Research Review by Dr. Shawn Thistle©

Date:

2005

Study Title:

Intakes of whole grains, bran, and germ and the risk of coronary heart disease in men

Authors:

Jensen MK, Koh-Banjeree P, Hu FB, Franz M, Sampson L, Grønbæk, Rimm EB

Publication Information:

American Journal of Clinical Nutrition 2004; 80: 1492-1499

Summary:

Intake of whole grains has been associated with a reduced incidence of coronary heart disease (CHD) in many large, prospective cohort studies.

Whole grains contain a number of nutrients such as fiber, vitamin E, vitamin B-6, minerals, anti-oxidants, and phytoestrogens, all of which have well-documented health benefits.

The objective of this study was to clarify some previous methodological discrepancies in this field of research, while evaluating the association of whole grain, bran and germ intakes with the incidence of CHD.

This study, utilizing a prospective cohort design, followed more than 40 000 male health care professionals over a period of 14 years starting in 1986. At the beginning of the study, participants were between the ages of 40-75 and were free of cardiovascular disease, cancer, and diabetes.

Detailed self-administered food frequency questionnaires (FFQ) and health and lifestyle questionnaires were administered at inception, and every two years thereafter for the course of the study. Outcome measures included non-fatal and fatal myocardial infarction (heart attack) occurring between 1986 and January 31 2000. These heart attacks were measured through biennial questionnaires and medical records according to World Health Organization criteria.

Results indicated that cold breakfast cereals were the largest source of whole grains, contributing 33% of total intake. Brown rice, dark bread, and cooked oats were also significant contributors to whole grain intake. Intakes were then divided into quartiles and compared to the incidence of CHD and heart attack.

Compared with the lower intake categories, higher whole grain intake (i.e. top quartile) was associated with a lower body mass index, increased physical activity, less smoking, lower blood pressure. Further, men who consumed more whole grains also ate more protein, vegetables, fruit and had lower intakes of alcohol and fat. Finally, in the age-adjusted analysis, a strong inverse association was found between whole grain intake and risk of fatal and non-fatal heart disease and heart attack. That is, the more whole grains consumed, the lower he risk of heart attack. Men in the highest intake group reduced their risk of CHD by 36% compared to those in the lowest intake group.

Conclusions & Practical Application:

This large study of male health professionals found a distinct relationship between whole grain intake and reduced risk of heart disease.

Further, I think an interesting finding was the association of high whole grain intake with other healthy lifestyle patterns, such as not smoking, exercising, and other healthy diet habits such as increased fruit and vegetable intake. This emphasizes a point that many of us in the fitness industry continue to preach - that being healthy is an overall approach, and no single lifestyle or diet adaptation alone can reverse poor health and diet patterns.

Please consult your team of health professionals before making any radical changes to your diet, or beginning a new exercise program. As always, consult your healthcare professional before adding any dietary supplement to your plan.