The skinny on saturated fat

James Beckerman, M.D., FACC
Cardiologist, Providence St. Vincent Medical Center
Providence St. Vincent Heart Clinic-Cardiology

Published June 2010

For more than 40 years, physicians have been recommending a relatively consistent dietary approach to prevent heart disease.

We tell our patients to avoid saturated fat from animal products and to increase intake of fruits and vegetables. This recommendation is widespread and widely endorsed by the American Heart Association and other organizations.

Scientists have begun to question the saturated fat-heart disease hypothesis.
 
Most of us assume that these recommendations are evidence-based and current. After all, one would hope that a dietary recommendation shared with millions of people would be based on more than common sense, right?

Yet “common sense” and conventional wisdom have gotten us into trouble before. Remember when eggs were considered to be unhealthy? Eggs have relatively high amounts of cholesterol, and it was believed that consuming cholesterol would result in a significant increase in blood cholesterol levels. But it turns out that dietary cholesterol plays a pretty small role in cholesterol profiles. Saturated fat plays a much bigger role.

Once the science was convincing, doctors then reconsidered prior recommendations to avoid eggs. In fact, many of us recommend them as a high-protein breakfast food that actually may be preferable to refined carbohydrates and simple sugars found in many cereals and baked goods.

Surprises on saturated fat

So what about saturated fat? Given that saturated fat does appear to negatively impact cholesterol profiles, it seems obvious that reducing saturated fat intake should reduce the risk of heart disease.

But a growing number of journalists and scientists have begun to question the saturated fat-heart disease hypothesis, with increasing justification.

In recent months, a study published in the American Journal of Clinical Nutrition tried to solve the controversy once and for all. Pooled data from 20-plus studies and nearly 350,000 participants found no difference in the risk of heart disease between people with the lowest and highest intake of saturated fat.

Sure, it’s not a perfect study. Some of the research relies on people’s recollections of what they ate, and it’s hard to draw any conclusions about whether there may be some benefit to a low-saturated-fat diet in older or higher-risk populations.

But we can’t ignore such a clear challenge to our way of thinking and hope that it just goes away. We need more research, more data and more open minds. Many are calling for a new approach to official dietary recommendations that takes the focus off pyramids and nutrients such as protein and fat, and more toward general dietary patterns.

Most people now agree that highly processed foods and refined carbohydrates and sweets are not as good for us as a more plant-based diet rich with whole grains, unsaturated fats and animal protein from fish.

While the data may not entirely support avoiding saturated fat, some have argued that replacing saturated fats with unsaturated fats may yield some benefit. The moral of the story is that conventional wisdom and common sense can be trumped by scientific data if we allow ourselves to examine old problems with new perspectives.

Clinical articles by James Beckerman, M.D.