Low-fat doesn't work? Go deeper.

Philip J. Goscienski, M.D.

July 2007

It's enough to make you wonder if the Keystone Cops have been reincarnated within the healthcare community. The Cops were a zany group that romped through silent movies, so clumsy that at least a couple would tumble from a patrol wagon during every chase. Like 1900s-era Inspector Clouseau clones, they managed to collar the crooks by the end of the episode in spite of their ineptitude.

You can be forgiven if you think that the medical community is confused, contradictory or just plain wrong in the advice that they have been handing out about fats for a couple of decades — like the Keystone Cops in lab coats. Before you give up on them you need to know a little about how medical research gets reported.

An example of apparent medical contradiction appeared recently in reports about the Women's Health Initiative: a low fat diet won't protect post-menopausal women from heart disease and cancer. That makes revenue-producing headlines for the media but scientists who read the original report went beyond those headlines.

Discerning readers of the original article noted that there wasn't a large difference between the diets of the study group (29 percent fat calories) and the control group (37 percent fat calories) by the sixth year of this 8-year program. The diets were not tightly controlled or directly measured and researchers relied on self-reporting, a system that is hardly accurate. Besides, limiting fat intake doesn't protect you from becoming overweight or from developing heart disease if you replace those fats with foods that contain flour and sugar with just as many calories.

The researchers didn't compare the participants' intake of healthy versus harmful fats. That distinction is critical. Americans not only have a diet that is about 40 percent fat, most of that is saturated, which increases cholesterol levels. Much of Western-diet fat comes from deep-fried foods that contain by-products that are directly harmful to the lining of blood vessels. Perhaps the most dangerous fats are trans fats. These chemically altered fats have a different shape from those found in nature so the body can't use them as efficiently. The evidence that they are directly linked to heart disease and cancer is strong enough that the U.S. government has mandated labeling laws to identify them in all processed foods.

The traditional Mediterranean diet also provides about 40 percent of its calories from fat but virtually all of it comes from olive oil, which is mostly monounsaturated. Those who enjoy the true Mediterranean cuisine have barely a twentieth of the heart disease that is the leading cause of death in our country and lower rates of cancer as well.

It's not unusual for Arctic hunters to get more than 50 percent of their calories from fat but it's almost all polyunsaturated, which is heart-protective. The rest is monounsaturated.

The study simply showed that a slight reduction in overall fat intake doesn't matter much in preventing heart disease or cancer, but you could probably guess that. A major factor in maintaining good health is the elimination of the wrong kinds of fats, not all fats.

The Keystone Cops had it right on this one.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.