EVALUATION OF ADULTS’ WHOLE GRAIN CONSUMPTION AND THEIR ATTITUDES ABOUT WHOLE GRAINS
GÜLBİN IŞIKLI
UNDERGRADUATE THESIS STUDY
INSTRUCTOR
ASIST. PROF. DR. MÜJGAN ÖZTÜRK
EASTERN MEDITERRANEAN UNIVERSITY
JUNE, 2021
FAMAGUSTA, NORTH CYPRUS
OBJECTIVE: The aim of this study is to determine the whole grain consumption of adults and their attitudes and thoughts about whole grains.
METHODS: This study was done with 19-65 years old 50 adults in Aydın who don’t have any physical or psychologic sorun. All the participants voluntarily attended to the study. Adults’ whole grain consumption and their attitudes about whole grains were assessed using a questionnaire. The questionnaire consists of 4 parts including demographic characteristics, anthropometric measurements, knowledge and attitude to whole grains and food frequency questionnaire. Anthropometric measurements include weight and height, BMI, waist and hip circumference were measured for each participant. Knowledge and attitude to whole grains evaluated with the answers of the participants “yes”, “no” and/or “do not know”. The frequency of consumption is evaluated by every meal, every day, evvel or twice a week, 2-3 times a week, 3-4 times a week, 5-6 times a week, evvel a two week, evvel a month and never answers.
RESULTS: All the participants (100%) who had olağan weight or overweight heard about term of whole grain. However, only 66,7% of overweight or obese participants and 62,5% of participants who had olağan BMI knew the definition of whole grain. Besides, 94% of total participants described whole grain as 100% whole wheat. Also, 84,0% of total participants like the taste of whole grain and 94,4% of these participants were overweight and 78,1%of these participants were olağan weight. Moreover, %88,9 of overweight and 71,9% participants with olağan weight didn’t prefer taste of whole grain bread compared to taste of white bread. On the other hand, participants who said healthy for whole grain bread, the consumption was for olağan weight and overweight participants 26,03±32,50 g and 26,09≥±32,19 g respectively. Furthermore, participants who thoughts delicious for whole grain bread, overweight participants consumed 26,03≥±32,50 g and healthy weight participants consumed 25,35±23,40 g and there is no significant difference between overweight and healthy participants.
CONCLUSION: In conclusion, consumers’ consumption doesn’t change according to BMI except than rye bread. Consumers’ thoughts about whole grains differ according to BMI. Daily consumption amount of whole grain products doesn’t differ according to BMI but it differs according to gender. Consumers’ who thought whole grain bread delicious and/or healthy daily consumption amount of whole grain bread doesn’t differ according to BMI.
Consumers should be informed about the importance of whole grains in healthy eating habits. Promotion of whole grain products which frequently consumed such as bread, pasta and rice should be increased in the markets to increase daily consumption of whole grain products.
KEY WORDS: Whole grain, attitude, knowledge, consumption, BMI
To My Family and AllMy Loed Ones
I would like to thank warmly and gratitude to Asist. Prof. Dr. Müjgan ÖZTÜRK for guiding me with her vast knowledge and experience at every stage of my thesis work and for her support and understanding throughout the whole process.
Also, I would like to thank my dear family for their financial and moral support throughout my education.
TABLE OF CONTENTS
ABSTRACT.. i
DEDICATION.. i
ACKNOWLEDGEMENT.. i
1. INTRODUCTION.. 1
2. GENERAL INFORMATION.. 1
2.1. DEFINITION OF WHOLE GRAINS. 1
2.2. CONSUMER’S ATTITUDES TO WHOLE GRAINS. 1
2.3. DIET AND WHOLE GRAINS. 1
2.3.1. THE NUTRITIONAL COMPOSITION OF WHOLE GRAINS AND THEIR HEALTH BENEFITS. 1
2.4. RELATIONSHIP OF WHOLE GRAINS WITH DISEASES AND PUBLIC HEALTH 1
2.4.1. OBESITY.. 1
2.4.2. TYPE 2 DIABETES. 1
2.4.3. HYPERTENSION.. 1
2.4.4. CARDIOVASCULAR DISEASE.. 1
3. METHODOLOGY.. 1
3.1. THE PLACE AND TIME OF STUDY.. 1
3.2. POPULATION OF STUDY.. 1
3.3. VERİ COLLECTION.. 1
3.3.1. GENERAL INFORMATION COLLECTION.. 1
Table 3.1 BMI Classification (WHO, 2020) 1
Table 3.2. Waist to Hip Ratio Chart (WHO, 2020) 1
Table 3.3. Waist to Height Ratio Chart (TÜBER, 2016). 1
3.3.2. WHOLE GRAIN KNOWLEDGE.. 1
3.3.3. ATTITUDES TO WHOLE GRAINS. 1
3.3.4. FOOD FREQUENCY QUESSTIONNAIRE SPECIFIED FOR GRAINS 1
3.4. VERİ ANALYSIS. 1
4. RESULTS. 1
Tablo 4.1. Distribution of general information about consumers. 1
Table 4.2. Distribution of consumers according to lifestyle habits and health status. 1
Table 4.3. Distribution of age according to gender 1
Table 4.4. Distribution of consumer’s anthropometric measurements according to gender 1
Table 4.5. Distribution of consumer’s knowledge about whole grain according to BMI 1
Table 4.6. Distribution of recognizing whole grain products according to BMI. 1
Table 4.7. Consumer’s knowledge about recommended portion of whole grain consumption according to BMI. 1
Table 4.8. Distribution of consumer’s thoughts about the properties of whole grains according to BMI 1
Table 4.9. Comparison of daily grain consumption according to BMI. 1
Table 4.10. Comparison of daily grain consumption according to gender 1
Table 4.11. Distribution of whole grain bread consumption who thought healthy and/or delicious according to BMI. 1
5. DISCUSSION.. 1
5.1. SOCIODEMOGRAPHIC FEATURES. 1
5.2. KNOWLEDGE LEVEL OF WHOLE GRAINS. 1
5.3. ATTITUDE AGAINST WHOLE GRAINS. 1
5.4. GRAIN CONSUMPTION FREQUENCY.. 1
6. CONCLUSION.. 1
7. RECOMMENDATIONS. 1
REFERENCES. 1
9. APPENDIX.. 1
9.1. QUESTIONNAIRES. 1
ABBREVIATIONS
FDA U.S. Food and Drug Administration
AACC American Association for Clinical Chemistry
DGA Dietary Guidelines Advisory
NHANES National Health and Nutrition Examination Survey
WHO World Health Organization
SPSS Statistical Package for Social Sciences
BMI Body Mass Index
LIST OF FIGURES
Figure 2.1. The primary parts of Whole-wheat grain………………………………11
Figure 2.2. Whole grain intake of men in the world, 2010 (g/day)…………………12
Figure 2.3. Whole grain intake of women in the world, 2010 (g/day)………………13
LIST OF TABLES
Table 3.1 BMI Classification (WHO, 2020)………………………………………22
Table 3.2. Waist to Hip Ratio Chart (WHO, 2020)………………………………..22
Table 3.3. Waist to Height Ratio Chart (TÜBER, 2016)…………………………..23
Tablo 4.1. Distribution of general information about consumers………………….25
Table 4.2. Distribution of consumers according to lifestyle habits and health status…………………………………………………………………………………26
Table 4.3. Distribution of age according to gender…………………………………26
Table 4.4. Distribution of consumer’s anthropometric measurements according to gender……………………………………………………………………………….27
Table 4.5. Distribution of consumer’s knowledge about whole grain according to BMI…………………………………………………………………………………27
Table 4.6. Recognizing of whole grain products according to BMI…………………………………………………………………………………28
Table 4.7. Consumer’s knowledge about recommended portion of whole grain consumption according to BMI…………………………………………………….30
Table 4.8. Distribution of consumer’s thoughts about the properties of whole grains according to BMI…………………………………………………………………..31
Table 4.9. Comparison of daily grain consumption according to BMI……………32
Table 4.10. Comparison of daily grain consumption according to gender…………34
Table 4.11. Distribution of whole grain bread consumption who thought healthy and/or delicious according to BMI…………………………………………………36
1. INTRODUCTION
Cereals play an important role in nutrition (Marshall et al., 2020). Grain-based diets provide most of the world’s energy and nutrient requirements, supplying 25-50% of the daily calorie intake in the world. Dietary guidelines recommends 40-65% of energy as carbohydrates, with 65% considered by some to be high around the world (Julie Miller Jones et al., 2020).
Whole cereal grains are members of the Poaceae or Gramineae families (Beloshapka et al., 2016) and it has been a part of the human diet for millions of years (Shaltout et al., 2020). Foods made from whole grains are known to contain less starches and calories, more micronutrients and phytochemicals which can provide major health benefits instead of refined grain foods (Cho et al., 2013). Its fractions, bran and germ, consisting of specific bioactive components that promote wellbeing. The bran is the multi-layered outer skin that includes fiber, minerals, vitamins and bioactive compounds, among which it is of concern to identify phenolic acids as bioactive phytochemicals for significant effects on humans (Călinoiu & Vodnar, 2018).
Whole grain foods are often recognized by the use of food labeling and by their appearance and color (Foster et al., 2020). In the USDA/Health and Human Services Dietary Guidelines Advisory(DGA) Expert Panel report, examples of whole-grain foods and ingredients include brown rice, oatmeal, whole oats, cracked wheat, popcorn, whole rye and whole wheat (Cho et al., 2013), which has rich source of various bioactive compounds and dietary fibers (Jawhara et al., 2019). However, consumers may become confused while choosing refined grains instead of whole grain sources by mistake without sufficient knowledge of how to read a label and classify whole grains (Foster et al., 2020).
The inverse correlation between the daily consumption of whole grain foods and the risk of heart disease, some forms of cancer, type 2 diabetes, and body weight control has been investigated in extensive studies but whole grains intake is still below the recommended amounts around the world (EUFIC, 2015).
The aim of this study is to determine the whole grain consumption of adults and their attitudes and thoughts about whole grain.
2. GENERAL INFORMATION
2.1. DEFINITION OF WHOLE GRAINS
Whole grains are a group of cereal foods that have an intact grain (Marshall et al., 2020).Kernels of cereal grain consist of three main components: endosperm, bran, and germ (Kamp et al., 2014). There are viscous soluble fibers, fermentable oligosaccharides, resistant starch (RS), lignans, vitamins, minerals, polyphenols, oils, and other phytonutrients in the inner germ and starchy endosperm. The outer bran layer consists of nondigestible carbohydrates such as cellulose, hemicelluloses, arabinoxylan, mostly insoluble, poorly fermentable (Jonnalagadda et al., 2011)(Slavin et al., 2013).
Figure 2.1. The primary parts of Whole-wheat grain (Călinoiu & Vodnar, 2018).
There are differences between refined grains and whole grains. They differentiate by milling, pearling, polishing, or de-germing any or all of the outer bran layers (Julie Miller Jones et al., 2020). During the processing of whole grains into white flour, the outer bran and inner germ layers are removed and the residual endosperm is processed into flour.There are also major losses of essential minerals, vitamins, and phytonutrients as a result of the refining process (Jonnalagadda et al., 2011)(Slavin et al., 2013). These processes also reduce dietary fiber by about 75 percent and some of the antinutritional components contained in the bran(Julie Miller Jones et al., 2020). Thus, whole grains are naturally richer in dietary fiber compared to refined grains, producing approximately 80% more dietary fiber than refined grains (Jonnalagadda et al., 2011)(Slavin et al., 2013). The original grains undergo processing and reconstitution must have the same proportion of bran, germ and endosperm to be considered as whole grains (Jonnalagadda et al., 2011). A variety of definitions accept that whole grain products should contain over half their weight from whole grain sources (Seal & Brownlee, 2015).
According to the Cereals and Grains Association whole grains consist of the intact, ground, cracked, flaked or otherwise processed kernel after the elimination of indigestible components such as the hull and husk (Nirmala Prasadi & Joye, 2020). Asimilar definition is also doneby The U.S. Food and Drug Administration (FDA) and American Association of Cereal Chemists (AACC) International as those whole grains are intact, ground, cracked or flaked fruit of the grain which has principal components. The starchy endosperm, germ and bran, are present in the same relative proportions as they exist in the intact grain (Cooper et al., 2015)(Jonnalagadda et al., 2011). This description also makes it possible to minimize the loss of these three components throughout the course of the processing of whole grains (Seal & Brownlee, 2015). Small component losses under 2% of the germ or 10% of the bran, which can occur through safety and quality-consistent processing methods, are acceptable (Cooper et al., 2015). In order to be classified as a whole grain food by the International Cross-Disciplinary Group, at least 8 grams of each 30 gram of the product should be composed of whole grain (Seal & Brownlee, 2015).
Dietary guidelines currently provide suggestions for eating whole grains in many countries around the world (Mathews & Chu, 2020). Whole grain consumption of men and women around the world is showed below (figure 2.2. and figure 2.3.).
Figure 2.2.Whole grain intake of men in the world, 2010 (g/day) (GDD, 2015)
Figure 2.3. Whole grain intake of women in the world, 2010 (g/day) (GDD, 2015)
World Health Organization affirms whole grains as an essential part of balanced diet (WHO, 2021). However, whole grains intake is below the recommended amounts around the world (EUFIC, 2015). For example, more than 70 percent of people consume less than dietary guidelines and less than 2 servings (32 g of whole grains) of grains in the United Kingdom. In fact, 18% of adults and 15% of children / young people never consume grains (Mann et al., 2015). Moreover, 2011-2015 Danish national survey in Denmark recorded an average intake of 55 g for whole grains considerably lower than the recommended amount which is 75 g per day (Mathews & Chu, 2020).
Also, in a study published in France in 2014, 55 percent of children and 68 percent of adults never eat whole grains, half of participants consume whole grains day (Bellisle et al., 2014). Additionally, in a study conducted in Germany, 19% of children and adolescents do not consume whole grains and the general intake was 20-33 g / day which is around half of the recommendations (Alexy et al., 2010). Also, according to Turkey Nutrition and Health Survey (TBSA), the percentage of those who never consume whole grain bread is 71.4 percent in Turkey (TBSA, 2014).
The Swedish National Food Agency recommends a daily intake of approximately 70 g and 90 g of whole grain for women and men respectively (Nirmala Prasadi & Joye, 2020) while the 2015-2020 Dietary Guidelines for Americans suggest a en az equivalent 48 g of whole grains should be consumed per day in the United States. However, the National Health and Nutrition Survey (NHANES) for 2009-2010 showed average intakes of less than one third of the recommended amounts for all age groups in the US population (Mathews & Chu, 2020).
Although the recommendations differ from the general guidance on enhancing whole grains, the statistical guidelines identify a daily target amount to highlight the significance of eating whole grains for health maintenance (Mathews & Chu, 2020). Furthermore, the International Whole Grain Day emphasizes the importance of whole grain consumption and wellness, well-being and sustainability for healthier lives in the world per year on 19 November (George, 2020).
2.2. CONSUMER’S ATTITUDES TO WHOLE GRAINS
Whole Grains Council has been recorded the number of whole grain foods and a change to whole grain offerings increase in all categories (J. M. Jones & Sheats, 2015). Whole grain foods are often recognized by the use of food labeling and by their appearance and color. Consumers may become confused while choosing refined grains instead of whole grain sources by mistake without sufficient knowledge of how to read a label and classify whole grains. This inadvertently reduces whole grain consumption (Foster et al., 2020). In particular, there are variations in descriptions of what leads to the consumption of whole grain and what forms a whole grain food (Kissock et al., 2020). Due to the lack of consistency in the methods used to measure intakes, it is difficult to make comparisons between populations, to assess how whole grains exert their protective impact, the amounts needed to sustain better health and to evaluate the effectiveness of health promotion strategies (A. R. Jones et al., 2017).
Research indicates that low consumption of whole grains can be due to limited knowledge of whole grain foods, lack of link between whole grain and possible health benefits, unfavorable taste, limited time and knowledge for the preparation of whole grain foods (MacNab et al., 2017). Therefore, potential barriers to adequate whole grain consumption relate to taste, lack of knowledge of health benefits, family effects, price and availability of whole grains. Current research study shows that education, cost and taste were common factors identified by participants to help them select whole grain foods more frequently (Foster et al., 2020).
Singapore’s current strategies for public health are aimed at raising the regular consumption of whole grain foods, especially by offering out-of-home whole grain alternatives and using a symbol of healthier choice for food items. (Neo & Brownlee, 2017). Moreover, E.M. Barrett, et al. emphasize that awareness of consumer preferences and attitudes towards added-fiber grain foods relative to whole-grain foods, including current knowledge of whole grain and fiber benefits, is necessary to consider the utility of such items as a tool for enhancing the health value of grain choices (Barrett et al., 2020).
2.3. DIET AND WHOLE GRAINS
Cereal grains are one of the main food sources contributing up to 300 million tons a year in the world (Călinoiu & Vodnar, 2018). Worldwide, health promotion institutions accept the essential role of grain-based foods in their guidelines based on food groups. Since 2005, dietary guidance has emphasized the significance of whole grain foods by clearly mentioning that half of the grains should be whole grains (Julie Miller Jones et al., 2020). The Mediterranean Diet Pyramid also recommends that for each main meal 1-2 servings of cereal, particularly whole grain should be consumed (Ruggiero et al., 2019). However, a recent study analyzing consumption across 195 countries found that about 3 million deaths could be attributed to insufficient intake of whole grain in 2017, accounting for just 27 percent of the 11 million deaths attributed to any dietary risk factor (Barrett et al., 2020).
Due to their fractions, bran and germ, which contain specific health-promoting bioactive components, whole grains possess great nutritional and bioactive properties. In human intervention research, as well as a 2012-2016 World Health Organization survey, the evidence of health benefits supports the dietary intake of whole grains and whole-grain foods (Călinoiu & Vodnar, 2018).
2.3.1. THE NUTRITIONAL COMPOSITION OF WHOLE GRAINS AND THEIR HEALTH BENEFITS
The bran is the multi-layered outer skin that helps protect the other two components of the kernel from sunlight, pests, and water. Fiber, minerals such as iron, zinc, copper and magnesium, vitamin E, B group vitamins are found in the bran. Also, bran part has a variety of bioactive compounds such as flavonoids and carotenoids which have a beneficial biological impact on the body. New evidence indicates that they may be responsible for many of the health benefits of whole grains along with fiber. Additionally, the germ which is also known as embryo consist of essential unsaturated fats, B vitamins, selenium, vitamin E, antioxidants, plant sterols, and other compounds that are bioactive. Lastly, the largest part of the kernel is the endosperm, which primarily includes starchy carbohydrates, some proteins, and small quantities of fiber, vitamins, and minerals (EUFIC, 2015).
2.3.1.1. DIETARY FIBER
Dietary fiber was consumed as part of the carbohydrate fraction within food for millennia (Fuller et al., 2016). It has two types; soluble and insoluble fiber. Soluble fibers absorb water, which contributes to the formation of gel, which increases the transit time of food, delays gastric emptying, reduces the absorption of nutrients and slows digestion. Vegetables such as carrots, broccoli, onion, and artichokes and fruits such as bananas, berries, apples, and pears, as well as legumes, oats, and barley are food sources of soluble fiber. Besides insoluble fiber reduces transit time and increases fecal bulk and prevent constipation. Whole grain, wheat, bran, nuts, and seeds, as well as in some fruits and vegetables rich in insoluble fibers (Soliman, 2019).
Higher dietary fiber intake has inverse correlation between premature mortality, noncommunicable diseases and their risk factors in the general population (Reynolds et al., 2020).
2.3.1.2. CAROTENOIDS
Carotenoids are a category of pigments that are only synthesized by plants and microorganisms. Carotenoids have strong antioxidant properties and they are responsible for the red, yellow, and orange colors in fruits, vegetables, and whole grains. There are more than 600 carotenoids in nature and common types of carotenoids in whole grains include α and β-carotene, β-kryptoxanthin, zeaxanthin and lutein. Many biological processes have been linked to carotenoids including the prevention of chronic diseases, cardiovascular diseases and multiple cancers(Borneo & León, 2012).
2.3.1.3 PHENOLIC ACIDS
Phenolics are components that have one or more aromatic rings with one or more hydroxyl groups. Phenols, phenolic acids, and flavonoids are all phenolics. Common phenolic acids found in whole grains are ferulic acid which can be found in free, soluble or insoluble form such as corn, wheat, oats, rye. The health benefits of phenolic acids are generally associated with their antioxidant activity (Borneo & León, 2012). Phenolic acids are important to human health because they are potential antioxidants that prevent cell damage caused by free-radical oxidation processes. They are easily absorbed through intestinal tract walls. Humans’ anti-inflammation capacity is also enhanced by phenolic acids when consumed on a regular basis (Kumar & Goel, 2019).
2.3.1.4. VITAMINS AND MINERALS
A variety of B vitamins such as thiamin, riboflavin, niacin and folate and minerals such as iron, magnesium and selenium are essential composition of whole grains. B vitamins play a key role in metabolism and it is essential for healthy nervous system. Also, they support the body in releasing energy from protein, fat and carbohydrate. Moreover, folate helps the body form red blood cells which reduces the risk of neural tube defects and spina bifida during fetal development. In addition, Whole grains are source of magnesium and selenium. Magnesium is a mineral used in building bones and releasing energy from muscle. Selenium protects cells from oxidation. It is also important for a healthy immune system. Moreover, whole grain products are major source of non-heme iron which is used to carry oxygen in the blood (USDA, 2020).
2.4. RELATIONSHIP OF WHOLE GRAINS WITH DISEASES AND PUBLIC HEALTH
Current epidemiological studies indicate that the intake of whole grain components appears to be associated with a lower risk of different chronic lifestyle-related diseases especially type 2 diabetes, obesity, and cardiovascular diseases, hypertension, gastrointestinal cancer and mortality (Marshall et al., 2020) (Jawhara et al., 2019) (Călinoiu & Vodnar, 2018)(Kirwan et al., 2016). Additionally, some studies show that whole grains can reduce blood pressure, cholesterol and fasting glucose (Kirwan et al., 2016). Whole grain intake is also linked to improved health and treatment outcomes in some inflammation related chronic diseases and contributes to human-microbe symbiosis (Jawhara et al., 2019).
2.4.1. OBESITY
Overweight and obesity are international health concerns that keep rising (Kirwan et al., 2016). In 2016, The World Health Organization stated that 1.9 billion people are overweight and 650 million are obese. Current studies showed that there is an adverse association between whole grain intake and risk of obesity (Kikuchi et al., 2018)(Choumenkovitch et al., 2013)(Ye et al., 2012). According to the World Health Organization report, whole grain consumption may reduce the risk of obesity (WHO, 2018). Also, systematic reviews and meta-analyses affirm positive correlations of whole grain consumption and body weight measures in observational and randomized control studies (Harland & Garton, 2008) (Pol et al., 2013)(Maki et al., 2019). Additionally, there are positive effects of whole grain consumption on body weight, BMI, percentage of body fat and waist circumference (Kissock et al., 2020b).
There are a variety of mechanisms that may help to weight control through the consumption of whole grains. One of these mechanisms is that the higher non-digestible carbohydrate content of whole grain product has a lower energy density (kilocalories/unit weight) (Călinoiu & Vodnar, 2018).
A whole grain enriched diet can lead to a greater difference in body composition (Kirwan et al., 2016) because it increases satiety and the feeling of fullness via dietary fiber (Călinoiu & Vodnar, 2018). Cross-sectional and long term prospective epidemiological studies show that the consumption of whole grains and whole grain products is related to decrease the risk of obesity and weight gain (Jonnalagadda et al., 2011) (Călinoiu & Vodnar, 2018).
Călinoiu and his friends showed in their study that, three servings of whole grain (48 g) per day may contribute to a lower body mass index, smaller waist circumference and lower body fat levels (Călinoiu & Vodnar, 2018).
2.4.2. TYPE 2 DIABETES
Diabetes is a chronic disease where the human body loses the capability to generate or use insulin effectively. Type 2 diabetes is a metabolic disorder caused by inadequate pancreatic insulin production (Nirmala Prasadi & Joye, 2020). It is a disease that impacts a rising percentage of the world’s population (Jonnalagadda et al., 2011). The International Diabetes Foundation has estimated that 463 million people have diabetes globally in 2019 and it will increase about 51% in the world by 2045 (Atlas, 2019). Besides, according to the World Health Organization, deaths from diabetes increased by 70% globally between 2000 and 2019 (WHO, 2021).
Several studies emphasized that type 2 diabetes risk decreases with high consumption of whole grain (McRae, 2017). Randomized controlled trials demonstrated that whole grain intake improves blood glucose regulation and insulin sensitivity. Also, it decreases fasting insulin level and insulin resistance (Călinoiu & Vodnar, 2018).
Whole grain products that naturally have a higher content of dietary fiber. It is an essential ingredient and isconsidered tobeat least partly responsible for these health benefits. A variety of human studies have shown an inverse association between cereal fiber consumption and the risk of type 2 diabetes. Increasing the daily consumption of fiber by 15g or up to 35g is predicted to reduce the risk of premature mortality in adults with diabetes (Reynolds et al., 2020). Furthermore, a cohort study which evaluated the risk of type 2 diabetes and different cereals and whole grain products consumption such as rye bread, whole grain bread and oatmeal/muesli found that people who consume 16 g of whole grain serving per day, have 11 percent and 7 percent lower type 2 diabetes risk for men and women respectively (Călinoiu & Vodnar, 2018).
2.4.3. HYPERTENSION
Hypertension has become a major public health sorun and causes death which has increased by 56.1% in the world (Kashino et al., 2020) and around one-third of the adult population worldwide has arterial hypertension (Valenzuela et al., 2020). There are indeed modifiable risk factors associated with hypertension such as unhealthy diets, physical inactivity, alcohol and tobacco use (Kashino et al., 2020). It is also a common comorbidity of obesity, which is a significant cardiovascular disease risk factor (Kirwan et al., 2016).
Heart-healthy diets such as the Dietary Approaches to Stop Hypertension (DASH) or the Mediterranean diet pattern are recommended for the prevention of hypertension (Byun et al., 2019). Both of these diets include whole grains (Fung et al., 2010), which has several kinds of nutrients such as fiber, vitamins and minerals (Kashino et al., 2020). These components reduce hypertension risk (Borneo & León, 2012).
A meta-analysis of four cohort studies done in the U.S. suggested that the risk of hypertension was inversely correlated with whole grain consumption (Kashino et al., 2020). The French NutriNet-Santé cohort recently reported that 15 percent lower hypertension risk odds for people who consume whole grains (Byun et al., 2019). In addition, the anti-inflammatory effects of whole grains can also lead to lower blood pressure and the risk of cardiovascular diseases (Jonnalagadda et al., 2011).
In the Health Professionals’ Report, people consuming at least 4 daily servings of whole grains per day have a 23 percent lower risk of hypertension (Byun et al., 2019).
2.4.4. CARDIOVASCULAR DISEASE
Cardiovascular disease (CVD) is a class of conditions that affect the heart or blood vessel structures or function. A combination of risk factors, such as tobacco use, unhealthy diet, obesity, lack of physical activity, excessive alcohol consumption, hypertension, diabetes and hyperlipidemia are typically the cause of heart attacks and strokes. It is one of the leading causes of death in the world (George, 2020). The World Health Organization estimated that 17.7 million people died from cardiovascular diseases in 2015 (WHO, 2018). Same organization also reported that cardiovascular disease will cause nearly 23.3 million deaths each year by 2030 (George, 2020).
Whole grain foods are recommended because of their cardioprotective properties, including dietary fibers, trace minerals and antioxidants (Wang et al., 2020). The aleurone-rich products due to their bioactive contents when they consumed regularly, it may considerably decrease plasma concentrations of the inflammatory marker, C-reactive protein which is significant risk factor for cardiovascular disease. Also, Whole grains are rich in phytochemicals that compete for absorption of cholesterol in the small intestine, reducing LDL cholesterol, a triggering factor for CVD (Călinoiu & Vodnar, 2018). The high intake of whole grain and bran mixtures had a greater positive effect on minimizing the risk of CVD death, CVD events, and heart failure (Călinoiu & Vodnar, 2018).
The most recent meta-analyses demonstrated that there is a strong inverse relationship between dietary whole grain intake and the occurrence of cardiovascular diseases (Călinoiu & Vodnar, 2018). Observational studies have reported intake of whole grain foods is associated with lower metabolic syndrome occurrence and lower CVD mortality rates (Wang et al., 2020). Framingham Offspring report also highlighted that whole-grain diets were inversely correlated with total cholesterol, low-density lipoprotein (LDL), cholesterol and body mass index (George, 2020).
George E. showed in his study that, people who consume 90 g of whole grains which is 3 servings, there is a substantial reduction in the risk of cardiovascular disease, stroke, and coronary heart disease (George, 2020). The Australian dietary guidelines clarified that grain foods which is primarily whole grains are recommended for adults at least 4 to 6 times a day, especially for people who is at high risk of cardiovascular diseases (Wang et al., 2020).
3. METHODOLOGY
3.1. THE PLACE AND TIME OF STUDY
This study was done in Aydın, Turkey between February 2021 and March 2021 dates.
3.2. POPULATION OF STUDY
This study was done on 19-65 years old 50 adults in Aydın who don’t have any physical or psychologic sorun. All the participants voluntarily attended to the study and they gave written informed consent.
3.3. VERİ COLLECTION
All questionnaires were done face to face individually. Although the duration of the questionnaires varies between individuals, grain knowledge and awareness level part about 7 minutes, whole grain consumption frequency and amount part of it took approximately 13 minutes and 20 minutes in total.
The questionnaire consists of 4 parts including demographic characteristics, anthropometric measurements, knowledge and attitude to whole grains and food frequency questionnaire.
3.3.1. GENERAL INFORMATION COLLECTION
In this part of the questionnaire, 11 questions were asked to participants which include demographic characteristics such as gender, age, marital status, occupation, income status, living place and other information like disorders, physical activity, alcohol consumption and smoking.
Anthropometric measurements include weight and height, BMI, waist and hip circumference, waist to hip ratio and waist to height ratio and they were measured for each participant. Participants were weighed with light clothes and without cardigans, coats, belts and shoes. Their pockets were emptied and jewelry was removed. Measurements were performed on an empty stomach and after urinate or defecation. Participants were not hold onto the anything to support and they were stand on both feet equally. Height measurement was taken by tape. Participants were on flat ground and against a flat surface such as a wall, stood Frankfurt plane with feet flat together. Also, legs were straight, arms were sides and shoulder were level against to the wall. They touched the wall with head, shoulders, buttocks and heels. BMI is a measure for signal of nutritional status in adults. It is defined as a person’s weight in kilograms divided by the square of the person’s height in meters (kg/m2). BMI is calculated by the researcher and evaluated according to the WHO classification.
Table 3.1 BMI Classification (WHO, 2020)
Waist Circumference is measured by tape. Participants stood and place a tape measured around middle, just above the hipbones. Tape was horizontal around the waist and it was not tight. The measurement was taken after the participants breath out.
Hip circumference is measured also by tape. Participants stood and place a tape measured around widest part of the hip. Tape was horizontal around the waist and it was not tight.
Waist to hip ratio is the dimensionless ratio of the circumference of the waist to that of the hips. It is as an indicator for risk of developing serious health conditions. This is calculated as waist measurement divided by hip measurement (W/H) and evaluated according to the WHO classification by the researcher.
Table 3.2. Waist to Hip Ratio Chart (WHO, 2020)
Waist to height ratio which is a measure of the distribution of body weight is defined as waist circumference divided by height and both measured in the same units and evaluated according to the Ashwell classification.
Table 3.3. Waist to Height Ratio Chart (TÜBER, 2016).
3.3.2. WHOLE GRAIN KNOWLEDGE
In this part of the questionnaire, the level of knowledge about whole grain and whole grain products are aimed to be evaluated. There are 3 questions about whole grain knowledge and the daily recommendation for consumption.
Among these questions, it was asked if the expression whole grain has been heard before and evaluated with the answers of the participants “yes”, “no” and “do not know”. Also, ‘’grain statement’’, ‘’color of the food’’, ‘’cereal’’, 100% whole wheat, whole grain or multi-grain’’ information on the product packaging were asked if indicate either the food is whole grain or not by ‘’ yes’’ ‘’no’’ and ‘’I don’t know’’ answers to evaluate the information. In addition, whether various foods such as white bread, wheat bread, whole wheat bread, multigrain bread, rye bread, whole grain pasta and popcorn are whole grain answered by ‘’100% whole grain, not a whole grain and I do not know / not sure’’ answers. Lastly, questions were asked about the recommended daily portion of whole grain.
3.3.3. ATTITUDES TO WHOLE GRAINS
In this part of the questionnaire, both whole grain products and refined grain products were designed to determine the participant’s product preferences. Also, they were asked about digestion and health benefits of whole grains, taste, price, naturalness, satiety and nutritiousness. Moreover, they were asked to evaluate their thoughts on whether whole grains are usefulfor various diseases such as hypertension, type 2 diabetes, obesity, bowel diseases (constipation, diverticulum), heart disease and cancer with “yes”, “no” or “I don’t know” answers.
3.3.4. FOOD FREQUENCY QUESSTIONNAIRE SPECIFIED FOR GRAINS
In the third stage of the questionnaire, the grain consumption was asked. Questionnaire includes 23 items such as white flour, whole grain flour, whole grain / whole wheat bread and types, whole rye bread, types of white bread, multigrain bread, rice, brown rice, cracked wheat, buckwheat, pasta, whole cereal pasta / noodles / noodles, quinoa/chia/amaranth/flaxseed, oatmeal, muesli, granola/granola bar, whole grain breakfast cereal, popcorn and corn chips, crackers/biscuits/cake, whole grain crackers / biscuits/cake.
The frequency of consumption is evaluated by every meal, every day, evvel or twice a week, 2-3 times a week, 3-4 times a week, 5-6 times a week, evvel a two week, evvel a month and never answers.
In line with the measurements given in the second part, where the consumption of cereal foods is evaluated, the question how much they were asked to indicate the amount they consumed.
Daily grain consumption of individuals was analyzed with a computer aided program developed for Turkey called ‘Nutrition Package Information Systems Program (BEBİS).
3.4. VERİ ANALYSIS
In this research, the knowledge and attitude of whole grain and its relationship with consumption among adults who lives in Aydın, Turkey has been evaluated. The veri obtained was analyzed with appropriate statistical techniques within the scope of the study with Statistical Package for Social Sciences (SPSS) program.
4. RESULTS
Tablo 4.1. Distribution of general information about consumers
GÜLBİN IŞIKLI
UNDERGRADUATE THESIS STUDY
INSTRUCTOR
ASIST. PROF. DR. MÜJGAN ÖZTÜRK
EASTERN MEDITERRANEAN UNIVERSITY
JUNE, 2021
FAMAGUSTA, NORTH CYPRUS
OBJECTIVE: The aim of this study is to determine the whole grain consumption of adults and their attitudes and thoughts about whole grains.
METHODS: This study was done with 19-65 years old 50 adults in Aydın who don’t have any physical or psychologic sorun. All the participants voluntarily attended to the study. Adults’ whole grain consumption and their attitudes about whole grains were assessed using a questionnaire. The questionnaire consists of 4 parts including demographic characteristics, anthropometric measurements, knowledge and attitude to whole grains and food frequency questionnaire. Anthropometric measurements include weight and height, BMI, waist and hip circumference were measured for each participant. Knowledge and attitude to whole grains evaluated with the answers of the participants “yes”, “no” and/or “do not know”. The frequency of consumption is evaluated by every meal, every day, evvel or twice a week, 2-3 times a week, 3-4 times a week, 5-6 times a week, evvel a two week, evvel a month and never answers.
RESULTS: All the participants (100%) who had olağan weight or overweight heard about term of whole grain. However, only 66,7% of overweight or obese participants and 62,5% of participants who had olağan BMI knew the definition of whole grain. Besides, 94% of total participants described whole grain as 100% whole wheat. Also, 84,0% of total participants like the taste of whole grain and 94,4% of these participants were overweight and 78,1%of these participants were olağan weight. Moreover, %88,9 of overweight and 71,9% participants with olağan weight didn’t prefer taste of whole grain bread compared to taste of white bread. On the other hand, participants who said healthy for whole grain bread, the consumption was for olağan weight and overweight participants 26,03±32,50 g and 26,09≥±32,19 g respectively. Furthermore, participants who thoughts delicious for whole grain bread, overweight participants consumed 26,03≥±32,50 g and healthy weight participants consumed 25,35±23,40 g and there is no significant difference between overweight and healthy participants.
CONCLUSION: In conclusion, consumers’ consumption doesn’t change according to BMI except than rye bread. Consumers’ thoughts about whole grains differ according to BMI. Daily consumption amount of whole grain products doesn’t differ according to BMI but it differs according to gender. Consumers’ who thought whole grain bread delicious and/or healthy daily consumption amount of whole grain bread doesn’t differ according to BMI.
Consumers should be informed about the importance of whole grains in healthy eating habits. Promotion of whole grain products which frequently consumed such as bread, pasta and rice should be increased in the markets to increase daily consumption of whole grain products.
KEY WORDS: Whole grain, attitude, knowledge, consumption, BMI
To My Family and AllMy Loed Ones
I would like to thank warmly and gratitude to Asist. Prof. Dr. Müjgan ÖZTÜRK for guiding me with her vast knowledge and experience at every stage of my thesis work and for her support and understanding throughout the whole process.
Also, I would like to thank my dear family for their financial and moral support throughout my education.
TABLE OF CONTENTS
ABSTRACT.. i
DEDICATION.. i
ACKNOWLEDGEMENT.. i
1. INTRODUCTION.. 1
2. GENERAL INFORMATION.. 1
2.1. DEFINITION OF WHOLE GRAINS. 1
2.2. CONSUMER’S ATTITUDES TO WHOLE GRAINS. 1
2.3. DIET AND WHOLE GRAINS. 1
2.3.1. THE NUTRITIONAL COMPOSITION OF WHOLE GRAINS AND THEIR HEALTH BENEFITS. 1
2.4. RELATIONSHIP OF WHOLE GRAINS WITH DISEASES AND PUBLIC HEALTH 1
2.4.1. OBESITY.. 1
2.4.2. TYPE 2 DIABETES. 1
2.4.3. HYPERTENSION.. 1
2.4.4. CARDIOVASCULAR DISEASE.. 1
3. METHODOLOGY.. 1
3.1. THE PLACE AND TIME OF STUDY.. 1
3.2. POPULATION OF STUDY.. 1
3.3. VERİ COLLECTION.. 1
3.3.1. GENERAL INFORMATION COLLECTION.. 1
Table 3.1 BMI Classification (WHO, 2020) 1
Table 3.2. Waist to Hip Ratio Chart (WHO, 2020) 1
Table 3.3. Waist to Height Ratio Chart (TÜBER, 2016). 1
3.3.2. WHOLE GRAIN KNOWLEDGE.. 1
3.3.3. ATTITUDES TO WHOLE GRAINS. 1
3.3.4. FOOD FREQUENCY QUESSTIONNAIRE SPECIFIED FOR GRAINS 1
3.4. VERİ ANALYSIS. 1
4. RESULTS. 1
Tablo 4.1. Distribution of general information about consumers. 1
Table 4.2. Distribution of consumers according to lifestyle habits and health status. 1
Table 4.3. Distribution of age according to gender 1
Table 4.4. Distribution of consumer’s anthropometric measurements according to gender 1
Table 4.5. Distribution of consumer’s knowledge about whole grain according to BMI 1
Table 4.6. Distribution of recognizing whole grain products according to BMI. 1
Table 4.7. Consumer’s knowledge about recommended portion of whole grain consumption according to BMI. 1
Table 4.8. Distribution of consumer’s thoughts about the properties of whole grains according to BMI 1
Table 4.9. Comparison of daily grain consumption according to BMI. 1
Table 4.10. Comparison of daily grain consumption according to gender 1
Table 4.11. Distribution of whole grain bread consumption who thought healthy and/or delicious according to BMI. 1
5. DISCUSSION.. 1
5.1. SOCIODEMOGRAPHIC FEATURES. 1
5.2. KNOWLEDGE LEVEL OF WHOLE GRAINS. 1
5.3. ATTITUDE AGAINST WHOLE GRAINS. 1
5.4. GRAIN CONSUMPTION FREQUENCY.. 1
6. CONCLUSION.. 1
7. RECOMMENDATIONS. 1
REFERENCES. 1
9. APPENDIX.. 1
9.1. QUESTIONNAIRES. 1
ABBREVIATIONS
FDA U.S. Food and Drug Administration
AACC American Association for Clinical Chemistry
DGA Dietary Guidelines Advisory
NHANES National Health and Nutrition Examination Survey
WHO World Health Organization
SPSS Statistical Package for Social Sciences
BMI Body Mass Index
LIST OF FIGURES
Figure 2.1. The primary parts of Whole-wheat grain………………………………11
Figure 2.2. Whole grain intake of men in the world, 2010 (g/day)…………………12
Figure 2.3. Whole grain intake of women in the world, 2010 (g/day)………………13
LIST OF TABLES
Table 3.1 BMI Classification (WHO, 2020)………………………………………22
Table 3.2. Waist to Hip Ratio Chart (WHO, 2020)………………………………..22
Table 3.3. Waist to Height Ratio Chart (TÜBER, 2016)…………………………..23
Tablo 4.1. Distribution of general information about consumers………………….25
Table 4.2. Distribution of consumers according to lifestyle habits and health status…………………………………………………………………………………26
Table 4.3. Distribution of age according to gender…………………………………26
Table 4.4. Distribution of consumer’s anthropometric measurements according to gender……………………………………………………………………………….27
Table 4.5. Distribution of consumer’s knowledge about whole grain according to BMI…………………………………………………………………………………27
Table 4.6. Recognizing of whole grain products according to BMI…………………………………………………………………………………28
Table 4.7. Consumer’s knowledge about recommended portion of whole grain consumption according to BMI…………………………………………………….30
Table 4.8. Distribution of consumer’s thoughts about the properties of whole grains according to BMI…………………………………………………………………..31
Table 4.9. Comparison of daily grain consumption according to BMI……………32
Table 4.10. Comparison of daily grain consumption according to gender…………34
Table 4.11. Distribution of whole grain bread consumption who thought healthy and/or delicious according to BMI…………………………………………………36
1. INTRODUCTION
Cereals play an important role in nutrition (Marshall et al., 2020). Grain-based diets provide most of the world’s energy and nutrient requirements, supplying 25-50% of the daily calorie intake in the world. Dietary guidelines recommends 40-65% of energy as carbohydrates, with 65% considered by some to be high around the world (Julie Miller Jones et al., 2020).
Whole cereal grains are members of the Poaceae or Gramineae families (Beloshapka et al., 2016) and it has been a part of the human diet for millions of years (Shaltout et al., 2020). Foods made from whole grains are known to contain less starches and calories, more micronutrients and phytochemicals which can provide major health benefits instead of refined grain foods (Cho et al., 2013). Its fractions, bran and germ, consisting of specific bioactive components that promote wellbeing. The bran is the multi-layered outer skin that includes fiber, minerals, vitamins and bioactive compounds, among which it is of concern to identify phenolic acids as bioactive phytochemicals for significant effects on humans (Călinoiu & Vodnar, 2018).
Whole grain foods are often recognized by the use of food labeling and by their appearance and color (Foster et al., 2020). In the USDA/Health and Human Services Dietary Guidelines Advisory(DGA) Expert Panel report, examples of whole-grain foods and ingredients include brown rice, oatmeal, whole oats, cracked wheat, popcorn, whole rye and whole wheat (Cho et al., 2013), which has rich source of various bioactive compounds and dietary fibers (Jawhara et al., 2019). However, consumers may become confused while choosing refined grains instead of whole grain sources by mistake without sufficient knowledge of how to read a label and classify whole grains (Foster et al., 2020).
The inverse correlation between the daily consumption of whole grain foods and the risk of heart disease, some forms of cancer, type 2 diabetes, and body weight control has been investigated in extensive studies but whole grains intake is still below the recommended amounts around the world (EUFIC, 2015).
The aim of this study is to determine the whole grain consumption of adults and their attitudes and thoughts about whole grain.
2. GENERAL INFORMATION
2.1. DEFINITION OF WHOLE GRAINS
Whole grains are a group of cereal foods that have an intact grain (Marshall et al., 2020).Kernels of cereal grain consist of three main components: endosperm, bran, and germ (Kamp et al., 2014). There are viscous soluble fibers, fermentable oligosaccharides, resistant starch (RS), lignans, vitamins, minerals, polyphenols, oils, and other phytonutrients in the inner germ and starchy endosperm. The outer bran layer consists of nondigestible carbohydrates such as cellulose, hemicelluloses, arabinoxylan, mostly insoluble, poorly fermentable (Jonnalagadda et al., 2011)(Slavin et al., 2013).
Figure 2.1. The primary parts of Whole-wheat grain (Călinoiu & Vodnar, 2018).
There are differences between refined grains and whole grains. They differentiate by milling, pearling, polishing, or de-germing any or all of the outer bran layers (Julie Miller Jones et al., 2020). During the processing of whole grains into white flour, the outer bran and inner germ layers are removed and the residual endosperm is processed into flour.There are also major losses of essential minerals, vitamins, and phytonutrients as a result of the refining process (Jonnalagadda et al., 2011)(Slavin et al., 2013). These processes also reduce dietary fiber by about 75 percent and some of the antinutritional components contained in the bran(Julie Miller Jones et al., 2020). Thus, whole grains are naturally richer in dietary fiber compared to refined grains, producing approximately 80% more dietary fiber than refined grains (Jonnalagadda et al., 2011)(Slavin et al., 2013). The original grains undergo processing and reconstitution must have the same proportion of bran, germ and endosperm to be considered as whole grains (Jonnalagadda et al., 2011). A variety of definitions accept that whole grain products should contain over half their weight from whole grain sources (Seal & Brownlee, 2015).
According to the Cereals and Grains Association whole grains consist of the intact, ground, cracked, flaked or otherwise processed kernel after the elimination of indigestible components such as the hull and husk (Nirmala Prasadi & Joye, 2020). Asimilar definition is also doneby The U.S. Food and Drug Administration (FDA) and American Association of Cereal Chemists (AACC) International as those whole grains are intact, ground, cracked or flaked fruit of the grain which has principal components. The starchy endosperm, germ and bran, are present in the same relative proportions as they exist in the intact grain (Cooper et al., 2015)(Jonnalagadda et al., 2011). This description also makes it possible to minimize the loss of these three components throughout the course of the processing of whole grains (Seal & Brownlee, 2015). Small component losses under 2% of the germ or 10% of the bran, which can occur through safety and quality-consistent processing methods, are acceptable (Cooper et al., 2015). In order to be classified as a whole grain food by the International Cross-Disciplinary Group, at least 8 grams of each 30 gram of the product should be composed of whole grain (Seal & Brownlee, 2015).
Dietary guidelines currently provide suggestions for eating whole grains in many countries around the world (Mathews & Chu, 2020). Whole grain consumption of men and women around the world is showed below (figure 2.2. and figure 2.3.).
Figure 2.2.Whole grain intake of men in the world, 2010 (g/day) (GDD, 2015)
Figure 2.3. Whole grain intake of women in the world, 2010 (g/day) (GDD, 2015)
World Health Organization affirms whole grains as an essential part of balanced diet (WHO, 2021). However, whole grains intake is below the recommended amounts around the world (EUFIC, 2015). For example, more than 70 percent of people consume less than dietary guidelines and less than 2 servings (32 g of whole grains) of grains in the United Kingdom. In fact, 18% of adults and 15% of children / young people never consume grains (Mann et al., 2015). Moreover, 2011-2015 Danish national survey in Denmark recorded an average intake of 55 g for whole grains considerably lower than the recommended amount which is 75 g per day (Mathews & Chu, 2020).
Also, in a study published in France in 2014, 55 percent of children and 68 percent of adults never eat whole grains, half of participants consume whole grains day (Bellisle et al., 2014). Additionally, in a study conducted in Germany, 19% of children and adolescents do not consume whole grains and the general intake was 20-33 g / day which is around half of the recommendations (Alexy et al., 2010). Also, according to Turkey Nutrition and Health Survey (TBSA), the percentage of those who never consume whole grain bread is 71.4 percent in Turkey (TBSA, 2014).
The Swedish National Food Agency recommends a daily intake of approximately 70 g and 90 g of whole grain for women and men respectively (Nirmala Prasadi & Joye, 2020) while the 2015-2020 Dietary Guidelines for Americans suggest a en az equivalent 48 g of whole grains should be consumed per day in the United States. However, the National Health and Nutrition Survey (NHANES) for 2009-2010 showed average intakes of less than one third of the recommended amounts for all age groups in the US population (Mathews & Chu, 2020).
Although the recommendations differ from the general guidance on enhancing whole grains, the statistical guidelines identify a daily target amount to highlight the significance of eating whole grains for health maintenance (Mathews & Chu, 2020). Furthermore, the International Whole Grain Day emphasizes the importance of whole grain consumption and wellness, well-being and sustainability for healthier lives in the world per year on 19 November (George, 2020).
2.2. CONSUMER’S ATTITUDES TO WHOLE GRAINS
Whole Grains Council has been recorded the number of whole grain foods and a change to whole grain offerings increase in all categories (J. M. Jones & Sheats, 2015). Whole grain foods are often recognized by the use of food labeling and by their appearance and color. Consumers may become confused while choosing refined grains instead of whole grain sources by mistake without sufficient knowledge of how to read a label and classify whole grains. This inadvertently reduces whole grain consumption (Foster et al., 2020). In particular, there are variations in descriptions of what leads to the consumption of whole grain and what forms a whole grain food (Kissock et al., 2020). Due to the lack of consistency in the methods used to measure intakes, it is difficult to make comparisons between populations, to assess how whole grains exert their protective impact, the amounts needed to sustain better health and to evaluate the effectiveness of health promotion strategies (A. R. Jones et al., 2017).
Research indicates that low consumption of whole grains can be due to limited knowledge of whole grain foods, lack of link between whole grain and possible health benefits, unfavorable taste, limited time and knowledge for the preparation of whole grain foods (MacNab et al., 2017). Therefore, potential barriers to adequate whole grain consumption relate to taste, lack of knowledge of health benefits, family effects, price and availability of whole grains. Current research study shows that education, cost and taste were common factors identified by participants to help them select whole grain foods more frequently (Foster et al., 2020).
Singapore’s current strategies for public health are aimed at raising the regular consumption of whole grain foods, especially by offering out-of-home whole grain alternatives and using a symbol of healthier choice for food items. (Neo & Brownlee, 2017). Moreover, E.M. Barrett, et al. emphasize that awareness of consumer preferences and attitudes towards added-fiber grain foods relative to whole-grain foods, including current knowledge of whole grain and fiber benefits, is necessary to consider the utility of such items as a tool for enhancing the health value of grain choices (Barrett et al., 2020).
2.3. DIET AND WHOLE GRAINS
Cereal grains are one of the main food sources contributing up to 300 million tons a year in the world (Călinoiu & Vodnar, 2018). Worldwide, health promotion institutions accept the essential role of grain-based foods in their guidelines based on food groups. Since 2005, dietary guidance has emphasized the significance of whole grain foods by clearly mentioning that half of the grains should be whole grains (Julie Miller Jones et al., 2020). The Mediterranean Diet Pyramid also recommends that for each main meal 1-2 servings of cereal, particularly whole grain should be consumed (Ruggiero et al., 2019). However, a recent study analyzing consumption across 195 countries found that about 3 million deaths could be attributed to insufficient intake of whole grain in 2017, accounting for just 27 percent of the 11 million deaths attributed to any dietary risk factor (Barrett et al., 2020).
Due to their fractions, bran and germ, which contain specific health-promoting bioactive components, whole grains possess great nutritional and bioactive properties. In human intervention research, as well as a 2012-2016 World Health Organization survey, the evidence of health benefits supports the dietary intake of whole grains and whole-grain foods (Călinoiu & Vodnar, 2018).
2.3.1. THE NUTRITIONAL COMPOSITION OF WHOLE GRAINS AND THEIR HEALTH BENEFITS
The bran is the multi-layered outer skin that helps protect the other two components of the kernel from sunlight, pests, and water. Fiber, minerals such as iron, zinc, copper and magnesium, vitamin E, B group vitamins are found in the bran. Also, bran part has a variety of bioactive compounds such as flavonoids and carotenoids which have a beneficial biological impact on the body. New evidence indicates that they may be responsible for many of the health benefits of whole grains along with fiber. Additionally, the germ which is also known as embryo consist of essential unsaturated fats, B vitamins, selenium, vitamin E, antioxidants, plant sterols, and other compounds that are bioactive. Lastly, the largest part of the kernel is the endosperm, which primarily includes starchy carbohydrates, some proteins, and small quantities of fiber, vitamins, and minerals (EUFIC, 2015).
2.3.1.1. DIETARY FIBER
Dietary fiber was consumed as part of the carbohydrate fraction within food for millennia (Fuller et al., 2016). It has two types; soluble and insoluble fiber. Soluble fibers absorb water, which contributes to the formation of gel, which increases the transit time of food, delays gastric emptying, reduces the absorption of nutrients and slows digestion. Vegetables such as carrots, broccoli, onion, and artichokes and fruits such as bananas, berries, apples, and pears, as well as legumes, oats, and barley are food sources of soluble fiber. Besides insoluble fiber reduces transit time and increases fecal bulk and prevent constipation. Whole grain, wheat, bran, nuts, and seeds, as well as in some fruits and vegetables rich in insoluble fibers (Soliman, 2019).
Higher dietary fiber intake has inverse correlation between premature mortality, noncommunicable diseases and their risk factors in the general population (Reynolds et al., 2020).
2.3.1.2. CAROTENOIDS
Carotenoids are a category of pigments that are only synthesized by plants and microorganisms. Carotenoids have strong antioxidant properties and they are responsible for the red, yellow, and orange colors in fruits, vegetables, and whole grains. There are more than 600 carotenoids in nature and common types of carotenoids in whole grains include α and β-carotene, β-kryptoxanthin, zeaxanthin and lutein. Many biological processes have been linked to carotenoids including the prevention of chronic diseases, cardiovascular diseases and multiple cancers(Borneo & León, 2012).
2.3.1.3 PHENOLIC ACIDS
Phenolics are components that have one or more aromatic rings with one or more hydroxyl groups. Phenols, phenolic acids, and flavonoids are all phenolics. Common phenolic acids found in whole grains are ferulic acid which can be found in free, soluble or insoluble form such as corn, wheat, oats, rye. The health benefits of phenolic acids are generally associated with their antioxidant activity (Borneo & León, 2012). Phenolic acids are important to human health because they are potential antioxidants that prevent cell damage caused by free-radical oxidation processes. They are easily absorbed through intestinal tract walls. Humans’ anti-inflammation capacity is also enhanced by phenolic acids when consumed on a regular basis (Kumar & Goel, 2019).
2.3.1.4. VITAMINS AND MINERALS
A variety of B vitamins such as thiamin, riboflavin, niacin and folate and minerals such as iron, magnesium and selenium are essential composition of whole grains. B vitamins play a key role in metabolism and it is essential for healthy nervous system. Also, they support the body in releasing energy from protein, fat and carbohydrate. Moreover, folate helps the body form red blood cells which reduces the risk of neural tube defects and spina bifida during fetal development. In addition, Whole grains are source of magnesium and selenium. Magnesium is a mineral used in building bones and releasing energy from muscle. Selenium protects cells from oxidation. It is also important for a healthy immune system. Moreover, whole grain products are major source of non-heme iron which is used to carry oxygen in the blood (USDA, 2020).
2.4. RELATIONSHIP OF WHOLE GRAINS WITH DISEASES AND PUBLIC HEALTH
Current epidemiological studies indicate that the intake of whole grain components appears to be associated with a lower risk of different chronic lifestyle-related diseases especially type 2 diabetes, obesity, and cardiovascular diseases, hypertension, gastrointestinal cancer and mortality (Marshall et al., 2020) (Jawhara et al., 2019) (Călinoiu & Vodnar, 2018)(Kirwan et al., 2016). Additionally, some studies show that whole grains can reduce blood pressure, cholesterol and fasting glucose (Kirwan et al., 2016). Whole grain intake is also linked to improved health and treatment outcomes in some inflammation related chronic diseases and contributes to human-microbe symbiosis (Jawhara et al., 2019).
2.4.1. OBESITY
Overweight and obesity are international health concerns that keep rising (Kirwan et al., 2016). In 2016, The World Health Organization stated that 1.9 billion people are overweight and 650 million are obese. Current studies showed that there is an adverse association between whole grain intake and risk of obesity (Kikuchi et al., 2018)(Choumenkovitch et al., 2013)(Ye et al., 2012). According to the World Health Organization report, whole grain consumption may reduce the risk of obesity (WHO, 2018). Also, systematic reviews and meta-analyses affirm positive correlations of whole grain consumption and body weight measures in observational and randomized control studies (Harland & Garton, 2008) (Pol et al., 2013)(Maki et al., 2019). Additionally, there are positive effects of whole grain consumption on body weight, BMI, percentage of body fat and waist circumference (Kissock et al., 2020b).
There are a variety of mechanisms that may help to weight control through the consumption of whole grains. One of these mechanisms is that the higher non-digestible carbohydrate content of whole grain product has a lower energy density (kilocalories/unit weight) (Călinoiu & Vodnar, 2018).
A whole grain enriched diet can lead to a greater difference in body composition (Kirwan et al., 2016) because it increases satiety and the feeling of fullness via dietary fiber (Călinoiu & Vodnar, 2018). Cross-sectional and long term prospective epidemiological studies show that the consumption of whole grains and whole grain products is related to decrease the risk of obesity and weight gain (Jonnalagadda et al., 2011) (Călinoiu & Vodnar, 2018).
Călinoiu and his friends showed in their study that, three servings of whole grain (48 g) per day may contribute to a lower body mass index, smaller waist circumference and lower body fat levels (Călinoiu & Vodnar, 2018).
2.4.2. TYPE 2 DIABETES
Diabetes is a chronic disease where the human body loses the capability to generate or use insulin effectively. Type 2 diabetes is a metabolic disorder caused by inadequate pancreatic insulin production (Nirmala Prasadi & Joye, 2020). It is a disease that impacts a rising percentage of the world’s population (Jonnalagadda et al., 2011). The International Diabetes Foundation has estimated that 463 million people have diabetes globally in 2019 and it will increase about 51% in the world by 2045 (Atlas, 2019). Besides, according to the World Health Organization, deaths from diabetes increased by 70% globally between 2000 and 2019 (WHO, 2021).
Several studies emphasized that type 2 diabetes risk decreases with high consumption of whole grain (McRae, 2017). Randomized controlled trials demonstrated that whole grain intake improves blood glucose regulation and insulin sensitivity. Also, it decreases fasting insulin level and insulin resistance (Călinoiu & Vodnar, 2018).
Whole grain products that naturally have a higher content of dietary fiber. It is an essential ingredient and isconsidered tobeat least partly responsible for these health benefits. A variety of human studies have shown an inverse association between cereal fiber consumption and the risk of type 2 diabetes. Increasing the daily consumption of fiber by 15g or up to 35g is predicted to reduce the risk of premature mortality in adults with diabetes (Reynolds et al., 2020). Furthermore, a cohort study which evaluated the risk of type 2 diabetes and different cereals and whole grain products consumption such as rye bread, whole grain bread and oatmeal/muesli found that people who consume 16 g of whole grain serving per day, have 11 percent and 7 percent lower type 2 diabetes risk for men and women respectively (Călinoiu & Vodnar, 2018).
2.4.3. HYPERTENSION
Hypertension has become a major public health sorun and causes death which has increased by 56.1% in the world (Kashino et al., 2020) and around one-third of the adult population worldwide has arterial hypertension (Valenzuela et al., 2020). There are indeed modifiable risk factors associated with hypertension such as unhealthy diets, physical inactivity, alcohol and tobacco use (Kashino et al., 2020). It is also a common comorbidity of obesity, which is a significant cardiovascular disease risk factor (Kirwan et al., 2016).
Heart-healthy diets such as the Dietary Approaches to Stop Hypertension (DASH) or the Mediterranean diet pattern are recommended for the prevention of hypertension (Byun et al., 2019). Both of these diets include whole grains (Fung et al., 2010), which has several kinds of nutrients such as fiber, vitamins and minerals (Kashino et al., 2020). These components reduce hypertension risk (Borneo & León, 2012).
A meta-analysis of four cohort studies done in the U.S. suggested that the risk of hypertension was inversely correlated with whole grain consumption (Kashino et al., 2020). The French NutriNet-Santé cohort recently reported that 15 percent lower hypertension risk odds for people who consume whole grains (Byun et al., 2019). In addition, the anti-inflammatory effects of whole grains can also lead to lower blood pressure and the risk of cardiovascular diseases (Jonnalagadda et al., 2011).
In the Health Professionals’ Report, people consuming at least 4 daily servings of whole grains per day have a 23 percent lower risk of hypertension (Byun et al., 2019).
2.4.4. CARDIOVASCULAR DISEASE
Cardiovascular disease (CVD) is a class of conditions that affect the heart or blood vessel structures or function. A combination of risk factors, such as tobacco use, unhealthy diet, obesity, lack of physical activity, excessive alcohol consumption, hypertension, diabetes and hyperlipidemia are typically the cause of heart attacks and strokes. It is one of the leading causes of death in the world (George, 2020). The World Health Organization estimated that 17.7 million people died from cardiovascular diseases in 2015 (WHO, 2018). Same organization also reported that cardiovascular disease will cause nearly 23.3 million deaths each year by 2030 (George, 2020).
Whole grain foods are recommended because of their cardioprotective properties, including dietary fibers, trace minerals and antioxidants (Wang et al., 2020). The aleurone-rich products due to their bioactive contents when they consumed regularly, it may considerably decrease plasma concentrations of the inflammatory marker, C-reactive protein which is significant risk factor for cardiovascular disease. Also, Whole grains are rich in phytochemicals that compete for absorption of cholesterol in the small intestine, reducing LDL cholesterol, a triggering factor for CVD (Călinoiu & Vodnar, 2018). The high intake of whole grain and bran mixtures had a greater positive effect on minimizing the risk of CVD death, CVD events, and heart failure (Călinoiu & Vodnar, 2018).
The most recent meta-analyses demonstrated that there is a strong inverse relationship between dietary whole grain intake and the occurrence of cardiovascular diseases (Călinoiu & Vodnar, 2018). Observational studies have reported intake of whole grain foods is associated with lower metabolic syndrome occurrence and lower CVD mortality rates (Wang et al., 2020). Framingham Offspring report also highlighted that whole-grain diets were inversely correlated with total cholesterol, low-density lipoprotein (LDL), cholesterol and body mass index (George, 2020).
George E. showed in his study that, people who consume 90 g of whole grains which is 3 servings, there is a substantial reduction in the risk of cardiovascular disease, stroke, and coronary heart disease (George, 2020). The Australian dietary guidelines clarified that grain foods which is primarily whole grains are recommended for adults at least 4 to 6 times a day, especially for people who is at high risk of cardiovascular diseases (Wang et al., 2020).
3. METHODOLOGY
3.1. THE PLACE AND TIME OF STUDY
This study was done in Aydın, Turkey between February 2021 and March 2021 dates.
3.2. POPULATION OF STUDY
This study was done on 19-65 years old 50 adults in Aydın who don’t have any physical or psychologic sorun. All the participants voluntarily attended to the study and they gave written informed consent.
3.3. VERİ COLLECTION
All questionnaires were done face to face individually. Although the duration of the questionnaires varies between individuals, grain knowledge and awareness level part about 7 minutes, whole grain consumption frequency and amount part of it took approximately 13 minutes and 20 minutes in total.
The questionnaire consists of 4 parts including demographic characteristics, anthropometric measurements, knowledge and attitude to whole grains and food frequency questionnaire.
3.3.1. GENERAL INFORMATION COLLECTION
In this part of the questionnaire, 11 questions were asked to participants which include demographic characteristics such as gender, age, marital status, occupation, income status, living place and other information like disorders, physical activity, alcohol consumption and smoking.
Anthropometric measurements include weight and height, BMI, waist and hip circumference, waist to hip ratio and waist to height ratio and they were measured for each participant. Participants were weighed with light clothes and without cardigans, coats, belts and shoes. Their pockets were emptied and jewelry was removed. Measurements were performed on an empty stomach and after urinate or defecation. Participants were not hold onto the anything to support and they were stand on both feet equally. Height measurement was taken by tape. Participants were on flat ground and against a flat surface such as a wall, stood Frankfurt plane with feet flat together. Also, legs were straight, arms were sides and shoulder were level against to the wall. They touched the wall with head, shoulders, buttocks and heels. BMI is a measure for signal of nutritional status in adults. It is defined as a person’s weight in kilograms divided by the square of the person’s height in meters (kg/m2). BMI is calculated by the researcher and evaluated according to the WHO classification.
Table 3.1 BMI Classification (WHO, 2020)
BMI | Nutritional Status |
Below 18.5 kg/m2 | Underweight |
18.5-24.9 kg/m2 | Olağan weight |
25.0-29.9 kg/m2 | Pre-obesity |
30.0-34.9 kg/m2 | Obesity class I |
35.0-39.9 kg/m2 | Obesity class II |
Above 40.0 kg/m2 | Obesity class III |
Waist Circumference is measured by tape. Participants stood and place a tape measured around middle, just above the hipbones. Tape was horizontal around the waist and it was not tight. The measurement was taken after the participants breath out.
Hip circumference is measured also by tape. Participants stood and place a tape measured around widest part of the hip. Tape was horizontal around the waist and it was not tight.
Waist to hip ratio is the dimensionless ratio of the circumference of the waist to that of the hips. It is as an indicator for risk of developing serious health conditions. This is calculated as waist measurement divided by hip measurement (W/H) and evaluated according to the WHO classification by the researcher.
Table 3.2. Waist to Hip Ratio Chart (WHO, 2020)
Health risk | Women | Men |
Low | 0.80 or lower | 0.95 or lower |
Moderate | 0.81–0.85 | 0.96–1.0 |
High | 0.86 or higher | 1.0 or higher |
Waist to height ratio which is a measure of the distribution of body weight is defined as waist circumference divided by height and both measured in the same units and evaluated according to the Ashwell classification.
Table 3.3. Waist to Height Ratio Chart (TÜBER, 2016).
Waist/Height | Classification |
p> | Risky |
0.4p> | Olağan |
0.5p> | Risky |
>0.6 | Needs Treatment |
3.3.2. WHOLE GRAIN KNOWLEDGE
In this part of the questionnaire, the level of knowledge about whole grain and whole grain products are aimed to be evaluated. There are 3 questions about whole grain knowledge and the daily recommendation for consumption.
Among these questions, it was asked if the expression whole grain has been heard before and evaluated with the answers of the participants “yes”, “no” and “do not know”. Also, ‘’grain statement’’, ‘’color of the food’’, ‘’cereal’’, 100% whole wheat, whole grain or multi-grain’’ information on the product packaging were asked if indicate either the food is whole grain or not by ‘’ yes’’ ‘’no’’ and ‘’I don’t know’’ answers to evaluate the information. In addition, whether various foods such as white bread, wheat bread, whole wheat bread, multigrain bread, rye bread, whole grain pasta and popcorn are whole grain answered by ‘’100% whole grain, not a whole grain and I do not know / not sure’’ answers. Lastly, questions were asked about the recommended daily portion of whole grain.
3.3.3. ATTITUDES TO WHOLE GRAINS
In this part of the questionnaire, both whole grain products and refined grain products were designed to determine the participant’s product preferences. Also, they were asked about digestion and health benefits of whole grains, taste, price, naturalness, satiety and nutritiousness. Moreover, they were asked to evaluate their thoughts on whether whole grains are usefulfor various diseases such as hypertension, type 2 diabetes, obesity, bowel diseases (constipation, diverticulum), heart disease and cancer with “yes”, “no” or “I don’t know” answers.
3.3.4. FOOD FREQUENCY QUESSTIONNAIRE SPECIFIED FOR GRAINS
In the third stage of the questionnaire, the grain consumption was asked. Questionnaire includes 23 items such as white flour, whole grain flour, whole grain / whole wheat bread and types, whole rye bread, types of white bread, multigrain bread, rice, brown rice, cracked wheat, buckwheat, pasta, whole cereal pasta / noodles / noodles, quinoa/chia/amaranth/flaxseed, oatmeal, muesli, granola/granola bar, whole grain breakfast cereal, popcorn and corn chips, crackers/biscuits/cake, whole grain crackers / biscuits/cake.
The frequency of consumption is evaluated by every meal, every day, evvel or twice a week, 2-3 times a week, 3-4 times a week, 5-6 times a week, evvel a two week, evvel a month and never answers.
In line with the measurements given in the second part, where the consumption of cereal foods is evaluated, the question how much they were asked to indicate the amount they consumed.
Daily grain consumption of individuals was analyzed with a computer aided program developed for Turkey called ‘Nutrition Package Information Systems Program (BEBİS).
3.4. VERİ ANALYSIS
In this research, the knowledge and attitude of whole grain and its relationship with consumption among adults who lives in Aydın, Turkey has been evaluated. The veri obtained was analyzed with appropriate statistical techniques within the scope of the study with Statistical Package for Social Sciences (SPSS) program.
4. RESULTS
Tablo 4.1. Distribution of general information about consumers
Frequency | % |