Soy Protein and Coronary Heart Disease: Knowledge, Attitudes, and Practices of College Students
Herring, Theresa A., Bakhiet, Raga M., Journal of Family and Consumer Sciences
This study assessed how knowledge of soy protein and its relationship to heart disease influences the attitudes and practices of college students. Results showed that family members, schools, and newspapers were the primary sources of students' nutritional information. One fourth of the participating students answered at least four nutrition knowledge questions correctly, and 53% were familiar with the term soy protein. Also, 40% knew that eating soy protein could lower their cholesterol, and 75% reported that they would change an eating habit if it benefited their health. Soy nutrition education programs should be implemented and soy foods should be promoted among college students.
Soy protein contributes to the prevention of coronary heart disease (CHD) by slowing atherosclerotic development (Wiseman et al., 2000) and by lowering total cholesterol and low-density lipoprotein (LDL) cholesterol (Sirtori & Lovati, 2001). Despite soy's many health benefits (Hecker, 2001; McCue & Shetty, 2004; Weisburger, 2000) and the Food and Drug Administration's approval of the claim that soy consumption may decrease the risk of CHD, consumption of soy is low in the United States. Soy could be a cost-effective and healthy means of aiding the prevention of CHD (Wenrich & Cason, 2004), and education about its benefits and ongoing research are important.
The purpose of this study was to establish whether there is a need for soy nutrition education among college students. A survey instrument was used to assess the knowledge, attitudes, and practices of students concerning soy protein and its relation to CHD. Although little research has been conducted in this area, incorporation of soy into young people's diets could benefit them at a pivotal point in their lives.
The Diet/Nutrition and Health Knowledge Survey (Rizek & Pao, 1990) was selected as the data collection tool. This survey helps link an individual's knowledge and attitudes to food choices and dietary behaviors. Seventeen questions were developed that spanned topics concerning knowledge, attitudes, and practices regarding soy foods and cholesterol and their relationship in prevention of CHD. Seven questions were designed to assess knowledge about soy protein and CHD prevention. For the purposes of this study, general nutrition knowledge was defined according to how many of five basic knowledge questions students answered correctly. Questions on familiarity with isoflavones and genistein were included to assess awareness of these soy components, which are under ongoing scientific inquiry. Six questions were designed to assess attitudes concerning soy protein use and prevention of CHD. Students' practices concerning soy protein use, acquisition of nutritional information, and prevention of hyperlipidemia were assessed via four questions. The project was approved by the study university's institutional review board.
The research questionnaire was tested for content by conferring with faculty members experienced in surveying knowledge and behaviors. The instrument was discussed with these faculty members and changes were made according to their recommendations. The survey was pilot tested with 20 students to ensure clarity of the items and to determine whether these students believed the survey served its purpose as explained to them. Administration of the survey to the same group of 10 students at two different points within the span of a week enabled assessment of test-retest reliability. The resulting correlation coefficient was .93, indicating high reliability.
Two hundred thirteen surveys were distributed to student volunteers. A heterogeneous sample of undergraduate students between the ages of 18 and 25 years was selected by asking every fourth student who passed a designated campus spot to complete the survey. If the student declined, the next student was asked. Students were recruited in the most frequented areas of the university: the library, student center, bookstore, and eating centers. Each student completed the survey at the time of recruitment and immediately gave it to the primary investigator. The survey was administered on 2 consecutive school days to lessen possible bias resulting from same-day schedules. Participants were informed that their responses would be anonymous.
Frequencies were calculated on all data. Comparisons were made among various responses and demographic subgroups to determine whether relationships existed between the variables. The chi-square statistic was used to determine whether relationships between variables were significant (p ≤ .05).
Students in the 18-21-year age range completed 84% of the surveys (2 surveys were completed by students falling outside of the designated age range, leaving 211 surveys available). Seventy-seven percent of the respondents were White, 9.5% were Black, 9.5% were Asian, and 3.3% were of other racial/ethnic backgrounds; two students did not provide their race/ethnicity. Male students made up 50.2% of the respondents, and female students accounted for 48.8%. Two students did not indicate their gender, and they were not included in the data analysis. A total of 209 responses were used in data analyses comparing relationships among gender, ethnicity, or degree of knowledge and other variables.
Eight students (3.8%) answered all five basic nutrition knowledge questions correctly. Approximately 22% answered four questions correctly. Several significant trends emerged in comparisons of degree of knowledge with other variables. For example, the more knowledgeable students were, the more likely they were to be concerned with the fat content of food (p = .024).
Slightly more than half of the students (51.7%) knew that CHD is the leading cause of death in the U. S. Approximately 95% knew that high cholesterol increases the risk of developing CHD, and 76% identified saturated fat as the type of fat that raises blood cholesterol. Only 14.7% of the students correctly identified LDL cholesterol as the "bad" type of cholesterol; students either incorrectly selected high-density lipoprotein cholesterol (42.7%) or indicated that they did not know (41.7%). About 40% of the students were aware of the effect of soy protein consumption on lowering blood cholesterol.
Regarding high-profile soy components, 4.3% of the students were familiar with genistein, 4.7% were familiar with isoflavone, and 53% were familiar with soy protein. In contrast, 93.8% were familiar with saturated fat; 75.8%, with polyunsaturated fat; 72%, with monounsaturated fat; 51.7%, with trans fatty acids; and 29.4%, with hydrogenation. Nutritional terms most frequently mentioned by students as confusing them were isoflavone (50.0%), trans fatty acids (33.0%), monounsaturated fat (26.3%), polyunsaturated fat (25.6%), saturated fat (11.6%), and soy protein (10.7%).
Regarding consumption of soy products, students who were more knowledgeable were more likely to consume soy nuts (p = .035), soy hot dogs (p = .003), miso (p = .019), soy ice cream (p = .005), soy cheese (p = .001), soy milk (p = .0001), and soy flour (p = .001). Similarly, students who were more knowledgeable were more likely to be familiar with soy and nutrition terms such as genistein (p = .005), isoflavone (p = .014), polyunsaturated fat (p = .015), saturated fat (p = .0001), and soy protein (p = .001).
The most frequently reported source of nutritional information was family members (25.1% of students), especially mothers. Following in frequency were magazines or newspapers (18.0%), school or classes (11.4%), doctor's offices (9.5%), TV programs (9.0%), friends (7.1%), journal articles (3.3%), and registered dietitians (2.8%). The most often reported source of information among the 84 students who reported that they were aware of the hypolipidemic effect of soy protein was a TV program (33%), followed in frequency by family members (32%), school (21%), and friends (21%).
Among those students who ate soy products, soy sauce was the most popular product (consumed by 52.6% of students), followed by soy burgers (36.0%), tofu (34.1%), and soy milk (22.3%). More than one fourth of the students (26.5%) had never consumed any soy products. Approximately 70% reported that they would eat a low-fat diet if they were at risk of hypercholesterolemia, 12.8% reported that they would eat a regular diet enriched with soy protein if they were at risk, and 10.0% reported that they would take a cholesterol-lowering drug.
Most of the students were concerned with the fat content (66.8%) or nutritional content (82.0%) of foods. However, 53.6% were not concerned with the cholesterol content of foods. Students who had consumed soy products mentioned taste (22.3%) and health (17.1%) as the two primary reasons. In order of frequency, other reasons mentioned were "like to try new things" (7.6%), "eating with family and friends" (7.1%), "was the only choice" (4.3%), "served at school" (2.8%), and "being a vegetarian" (1.9%). Among those who reported not eating any soy products, 12.3% believed they "would not like the taste," 9.5% were "not familiar with the preparation methods," and 7.6% "did not know the product existed." Most students (74.4%) reported that their primary reason to change an eating habit would be health concerns, followed in frequency by taste (11.8%) and price (5.7%).
Responses on attitude items revealed a relationship between gender and the primary reason students had not consumed a soy product (p = .0001). Male students were more likely to show a lack of interest in soy products, to think that they were costly, and to think that their taste was unacceptable. Conversely, female students were more likely to indicate that they were "not sure how to prepare" soy products. They were also more concerned with the fat (p = .0001), cholesterol (p = .042), and nutritional content (p = .043) of foods.
There was a significant relationship (p = .043) between ethnicity and awareness of the hypolipidemic effect of soy protein (Table 1). Asian students were more aware of soy's benefits and more likely to try soy products. Among the soy products, there were significant ethnic group differences for miso (p = .049), tofu (p = .048), soy milk (p = .0001), and soy flour (p = .047). More Asian than White students had tried miso, and no Black students had tried it. The majority (60%) of Asian students had eaten tofu, whereas the majority of White and Black students had not. The same pattern was evident for soy milk. Unlike Black and White students, Asian students were relatively unfamiliar with different types of fat (p = .009).
Ethnicity also was significantly related to students' primary sources of nutrition information (p = .014; Table 2). Asian students depended more on family members for information, whereas Blacks relied primarily on TV programs or doctor's offices. White students also relied mainly on family members, followed closely by magazines or newspapers, school or classes, doctor's offices, and friends. Another significant relationship was that between students' ethnicity and their choice of a cholesterol-lowering therapy if they were at risk of hypercholesterolemia (p = .013; Table 3). Although a majority of students of all ethnicities reported that they would opt for a low-fat diet, Asian students were more prone than students in other ethnic groups to indicate they would choose a regular diet enriched with soy. No Black students reported that they would opt for a cholesterol-lowering drug.
DISCUSSION AND CONCLUSIONS
Recognition must be given to small cell numbers in interpreting the practical significance of this study's findings. The fact that only 3.8% of students answered all five knowledge questions correctly and 22% answered four correctly may indicate the need for soy nutrition education at the college level. A similar trend in terms of lack of knowledge was observed in a study involving senior medical students in Taiwan (Hu, Liu, & Shieh, 1997). The influence of national nutrition education programs, education programs provided by family and consumer sciences (FCS) professionals in middle and high schools, and nutrition college education was demonstrated by the correct responses by most students to questions relating to the prevalence of and risk factors for CHD and the link between CHD and saturated fats.
The finding that female students were significantly more knowledgeable about basic nutrition than men and were more concerned with the fat, cholesterol, and nutritional content of foods indicates that they may feel more responsibility for acquiring food- and nutrition-related knowledge as a result of the traditional roles of women in the home. Because most male students were concerned with the nutritional content of food, education aimed at these students should stress the nutritional benefits of all food groups and, at the same time, highlight the benefits of soy (Wansink & Chan, 2001; Yamori, Miura, & Taira, 2001) within the context of the meat group. This recommendation was supported by the responses of the more knowledgeable students, who were more familiar with soy foods, more likely to consume soy foods or regular diets enriched with soy foods, and more concerned about fat content. Previous research (Pelletier, Kundrat, & Hasler, 2003; Verheijden & Kok, 2005) has shown that education modifies knowledge, which, in turn, changes behavior.
Ethnicity also played a role in this study. More Asian students knew about the hypolipidemic effect of soy protein. Conversely, Black students were the least likely to know, and the majority of White students were not aware of soy's benefits. Most of the students, regardless of ethnicity, learned about soy benefits from television or family members, or both. The same trend was observed for soy consumption. Many of the students were not familiar with the different types of fat. It may be that, with respect to different ethnic groups' knowledge regarding cholesterol and fat and their actual nutritional practices, lower degrees of familiarity are related to acculturation levels and reduced exposure to "heart-healthy" messages (see BenjaminGarner et al., 2002; Kaplan, Bhalodkar, Brown, White, & Brown, 2006). The differences observed among ethnic groups may indicate the need for targeted soy education programs.
In this study, students' primary reason for consuming or not consuming soy products was taste. A secondary reason (among soy consumers) was health. These results highlight the need for taste evaluations of soy products, cooking/baking demonstrations, and distribution of recipes (Pelletier et al., 2003; Wansink & Chan, 2001; Wenrich & Cason, 2004) and cookbooks. In addition, a widespread campaign on the health benefits of soy, within the context of the Food Guide Pyramid, would be timely. Studies have demonstrated soy's health benefits and acceptability to Americans (Pelletier et al., 2003).
Given that common sources of nutrition information for all students were family members, magazines or newspapers, and school or classes, a national campaign involving the use of these resources might be the most effective strategy (Benjamin-Garner et al., 2002). Introducing soy education to middle and high school students via programs designed by FCS professionals could prove beneficial to all ethnic groups.
In conclusion, notwithstanding this study's use of a nonprobability sample, soy nutrition education is recommended for the college population. Such a campaign could be implemented as an extension of the educational programs of the U.S. Department of Agriculture, the American Heart Association, and the American Cancer Society. An effective method may be including a basic nutrition course (or courses) as part of the university core curriculum required of all students and updating current courses to include discussions of the benefits of soy nutrition. Faculty and graduate students from nutrition and FCS departments could volunteer to speak at student organization meetings and residence halls, where samples of soy protein foods could be available for tasting. Students need to be aware of soy research so that they can follow developments in this evolving area and learn to adjust their nutrition practices on the basis of scientific findings.
Among those students who ate soy products, soy sauce was the most popular product (consumed by 52.6% of students), followed by soy burgers (36.0%), tofu (34.1%), and soy milk (22.3%).
In this study, students' primary reason for consuming or not consuming soy products was taste.
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Theresa A. Herring, PhD, RD
Department of Nutrition and
University of Nebraska-Lincoln
Raga M. Bakhiet, PhD
School of Mathematics, Science
Chula Vista, CA…
Questia, a part of Gale, Cengage Learning. www.questia.com
Publication information: Article title: Soy Protein and Coronary Heart Disease: Knowledge, Attitudes, and Practices of College Students. Contributors: Herring, Theresa A. - Author, Bakhiet, Raga M. - Author. Journal title: Journal of Family and Consumer Sciences. Volume: 99. Issue: 2 Publication date: April 2007. Page number: 16+. © American Association of Family & Consumer Sciences Apr 2008. Provided by ProQuest LLC. All Rights Reserved.
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