Dr. Howes – Whole grain diets have scant proof of being heart healthy

By Dr. Randolph M. Howes, M.D. Ph.D.

Times Columnist

Cereal advertisements constantly suggest that a diet heavy in whole high fiber grains has been proven to be of great benefit to your heart and cardiovascular health.

If so, where is the evidence?

Whole grain foods encompass a range of products and include whole grain wheat, rice, maize, and oats as well as milled whole grains such as oatmeal.

The American Heart Association recommends the Dietary Approaches to Stop Hypertension (DASH) diet or a Mediterranean-style diet to help prevent cardiovascular disease. Both diets emphasize cooking with vegetable oils with unsaturated fats, eating nuts, fruits, vegetables, low-fat dairy products, whole grains, fish and poultry, and limiting red meat and added sugars and salt.

But, studies published by the Cochrane Library, have found that experiments testing the heart benefits of whole grains have been too small, too brief, or both, making it impossible to determine how these foods might lead to long-term heart benefits in the general population. Basically, scientists have not yet proved beyond a doubt that a diet rich in whole grains is healthy for the heart.

Researchers, who analyzed only randomized controlled trials (RCTs), selected some healthy adults to consume lots of whole grains from products like cereal, rice and oats – and other healthy individuals to eat plenty of refined grains like white bread, or stick to their usual diets.

None of these experiments tested whether eating whole grains might influence the risk of dying from heart disease or having a heart attack or stroke, the research review found. All of the experiments did assess how consuming whole grains impacts risk factors for heart disease like blood pressure and cholesterol, however, and “none found a difference in these risk factors based on what types of grains people ate.”

Still, others argue that there is a large and undisputed body of evidence documenting the many health benefits of a diet rich in whole grains. It may be true that whole grains have been associated with lower weight gain, better cholesterol, glucose and insulin levels in previous studies, which are risk factors for heart disease. But, this is only an association and not a proven “cause and effect” relationship.

People must realize that high fiber grains are only one component of a healthy diet. Dr. Margo Denke said, “We have known for some time that fiber makes a small contribution to altering risk factors for heart disease. One needs to quit asking small modifications to bear the weight of the effects of a complete diet; diet is not a simple thing and diet is a composite, an overall approach to life.”
In the America that I love, we must not be misled by clever marketing tactics. Always eat a well-balanced diet.