Could slicing more fat from diet improve health?


November 11, 1992|By Kim Pierce | Kim Pierce,Dallas Morning News

Even as millions of Americans struggle to cut down on burgers and fries, ham and eggs, pie and ice cream, they may not be doing enough, some scientists say.

Reducing dietary fat even more -- to less than half the American Heart Association's recommended level -- would virtually wipe out heart disease, diabetes, obesity and some cancers, says a small but outspoken minority.

Following their suggestions would involve daunting dietary changes for all but the most motivated individuals. It would mean a diet made up almost entirely of fruits, vegetables, non-fat dairy products and grains, with no meats or added fats.

But if Americans held fat consumption to 10 percent to 15 percent of total calories, "heart disease could be as rare as polio or malaria," says Dr. Dean Ornish of the University of California at San Francisco. He has used diet and lifestyle changes to reverse artery damage in patients.

The heart association disputes claims that such a diet is better for you.

"There is no proof that a very low-fat diet will prevent disease any better than a moderate fat-restriction diet," says Dr. Margo Denke, assistant professor at the Center for Human Nutrition at the University of Texas Southwestern Medical School and nutrition committee member for the heart association.

Other researchers, however, say they so strongly believe less is more that they've changed their own eating habits.

Dr. Ornish is a vegetarian. So is Dr. T. Colin Campbell of Cornell University, the lead U.S. author on the ambitious China Project, a study for the diet-disease connection in 6,500 Chinese. Dr. R. James Barnard, a researcher at the University of California at Los Angeles who studies people on the Pritikin diet, limits meat, including fish, to a small, 3 1/2 -ounce portion daily.

All three eat lots of fruits, vegetables and grains -- and no added fat. Breakfast might be cereal with skim milk and fruit. Lunch might be greens with balsamic vinegar, and pasta with marinara sauce. Dinner might be rice and steamed vegetables drizzled with low-fat lemon-pepper sauce -- with, in Dr. Barnard's case, a small piece of broiled fish or beef. They snack on fruits, vegetables and non-fat yogurt.

By most measures, the diet is austere. For a 120-pound, moderately active woman who consumes 1,800 calories a day, 10 percent calories from fat would amount to 20 grams. Fifteen percent calories from fat would allow for 30 grams. Just eight Hershey kisses -- which contain 11 grams of fat -- would blow half the woman's daily allotment.

The same woman, using the heart association guidelines, could eat up to 60 grams of fat per day.

Proponents of the very low-fat diet concede it's a tough sell. Most Americans get about 40 percent of their daily calories from fat.

And most Americans, say public health officials, aren't prepared to make such sweeping dietary changes. The meat and dairy industries, as well as many nutritionists, maintain that meat and milk products are important elements of a healthful diet.

The paradox of a very low-fat diet is you actually eat more because per gram, fat has more than twice the calories of carbohydrates and protein.

The three researchers say they don't feel deprived. It's a matter of making different choices.

"The next time you go to Haagen-Dazs, instead of ice cream you get non-fat yogurt," says Dr. Barnard.

He studies clients of the Pritikin Longevity Center in Los Angeles, whose diet and exercise regimen has brought about dramatic reductions in blood cholesterol and triglyceride levels -- key factors in heart disease. The Pritikin diet aims for 10 percent of calories from fat with limited meat and dairy.

Dr. Ornish has not only prevented but actually reversed artery damage in patients, emphasizing a very low-fat diet, stress reduction and moderate exercise.

But no one has yet done a controlled, large-scale study comparing people on two diets -- one very low-fat, the other not -- to see whether it's the diet itself that cuts the risk of heart disease and cancer. Most conclusions are drawn from population studies, such as Dr. Campbell's in rural China.

Saturated fat -- the kind that's usually solid at room temperature -- is the major dietary culprit in heart disease. Too much makes the body overproduce cholesterol, which builds up inside blood vessels, restricting blood flow.

But it's not enough, says Dr. Barnard, to replace saturated fat with the other types, polyunsaturated and monounsaturated.

"Polys are important factors in cancer promotion," he says. "If you're trading off fats, you're trading off diseases: the No. 1 killer for the No. 2 killer."

How to cut saturated fat

A very low-fat diet may well prevent heart disease and cancer, says Dr. William Castelli, who leads the Framingham Heart Study in Massachusetts.

But cutting saturated fat, the biggest dietary culprit in heart disease, would be a step in the right direction, he says.

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