In a study published in The American Journal of Clinical Nutrition, Fung et al. examined overall dietary patterns, rather than individual nutrients, to identify risk factors for cardiovascular disease (CVD) and obesity. In a group of male health professionals, they described the "prudent" diet, which is characterized by higher intakes of fruits, vegetables, whole grains and poultry; and the "Western" diet, which is characterized by higher intakes of red meats, high fat dairy products and refined grains. The participants completed food frequency questionnaires every 4 years beginning in 1986, as well as questionnaires regarding a variety of lifestyle factors. The characterization of the diets as either prudent or Western was correlated with the subjects’ plasma biomarkers associated with either high or low risk of CVD and obesity. Individuals who scored higher on the Western diet pattern had higher plasma levels of biomarkers for higher CVD risk, as well as lower concentrations of folate, a nutrient found in fruits and vegetables that may protect against heart disease. In contrast, the prudent diet pattern was associated with a favorable biomarker profile. Information on lifestyles for the two groups tended to parallel the results of the dietary comparison.
The 82 participants in the study were 40-75 years of age in 1986, and were followed until 1994. They were divided into quintiles according to their adherence to either the prudent or Western dietary pattern. Eighteen biomarkers associated with CVD risk and obesity were measured, including HDL and LDL cholesterol, triacyglycerols, leptin, homocysteine, insulin and folate. Among consumers of the highest quintile of the Western diet, insulin, homocysteine and leptin were 18%, 9% and 16% higher, and folate was 8% lower than in the prudent diet group. The mean body mass index (BMI) of Western diet consumers was 25, the cutoff point for the classification of "overweight," which was somewhat higher than their prudent diet counterparts. They also had higher levels of insulin, leptin and c-peptides, all biomarkers strongly associated with obesity and diabetes mellitus. High consumers of the Western diet tended to have less healthy lifestyles than prudent dieters. Adherents to the highest quintile of the Western diet were 90% more likely to be smokers, watched 30% more television, engaged in 23% less physical activity and were 50% less likely to take a vitamin E supplement.
In an accompanying editorial by Jacques and Tucker, they address the strengths and limitations of the statistical approaches that have been used to study disease risk from the perspective of dietary patterns. The authors suggest that the state of methodology in studying dietary patterns is still limited by the inherent complexity of such broad-spectrum dietary data, and that further research should assess the power and stability of the various statistical approaches.
Fung, Teresa T. et al.Association between dietary patterns and plasma biomarkers of obesity and cardiovascular disease risk. Am J Clin Nutr,2001;73:61-7.
Jacques, Paul G. and Katherine L. Tucker. Are dietary patterns useful for understanding the role of diet in chronic disease? Am J Clin Nutr,2001;73:1-2.
This media release is provided by the American Society for Clinical Nutrition, to provide current information on nutrition-related research. This information should not be construed as medical advice. If you have a medical concern, consult your doctor. To see the complete text of this article, please go to: http://faseb.org/ajcn/January/11787-Fung.pdf
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American Journal of Clinical Nutrition