Does Animal Fat Get a Bum Rap?

Yesterday, BoingBoing.net ran a story about a large new study indicating that animal fat really isn’t all that hazardous. The blog entry concludes:

I guess I’ll keep frying my eggs in bacon grease!

I asked Virginia Messina, author of The Dietitian’s Guide to Vegetarian Diets, if she could write up a response. She kindly obliged:

A meta-analysis published in this month’s American Journal of Clinical Nutrition, funded in part by the National Dairy Council, suggested that there was “insufficient evidence from prospective epidemiologic studies” for a link between saturated fat and heart disease.

This isn’t the first study to find that the link between saturated fat and heart disease risk is weak. Nutritionists have long known that heart disease risk can’t be pinned down to one nutrient or dietary component. That doesn’t mean that a diet high in animal products gets a free pass, though.

First, the authors of this study noted that they weren’t able to determine if saturated fat might have an effect in specific age groups. Nor did they look at the possible effects of replacing saturated fat with unsaturated fats or carbohydrate. And the studies they used in their meta-analysis were epidemiologic—which means that they look for associations, not cause and effect. Other research recently published in the same journal found that replacing saturated fat with polyunsaturated fat did in fact reduce heart disease risk. (Am J Clin Nutr 2009;89:1425–32).

And last year, Canadian researchers reviewed studies going all the way back to 1950. They too found a weak association between saturated fat and heart disease. But they also found that a Mediterranean style diet—high in plant foods and unsaturated fats—was strongly protective against heart disease. And a Western dietary pattern (characterized by high intake of processed meat, red meat, butter, high-fat dairy, eggs, and refined grains) was strongly associated with increased risk.

In addition, two large epidemiological studies and one meta-analysis found that vegetarians—who eat more plant foods and fewer animal foods– were at lower risk of death from heart disease than non-vegetarians.

Whether or not saturated fat is the culprit remains to be seen. But the evidence still suggests that a diet based on plant foods is the best choice for reducing risk.

Sounds like eggs-in-bacon-grease isn’t such a hot idea after all.

Many thanks to Virginia for guest-blogging here. I’m a big fan of her blog; go check it out.