Originally published for Medscape Health for Consumers

It's nuts, but adding fat--the right kind of fat, that is--to your diet

may help keep your heart healthy.

A recent study published in the December 1999 issue of the

American Journal of Clinical Nutrition found that diets high in

monounsaturated fats have heart-healthy benefits more

valuable than those of a low-fat diet.

"This higher-fat diet seemed to be better in many ways

than a low-fat diet in reducing overall risk of

cardiovascular disease," says the author of the study.

Penny M. Kris-Etherton, PhD, RD. "A low-fat diet may in

fact increase risk of heart disease."

The primary sources of fat in this higher-fat diet are

peanuts, peanut butter, and peanut oil--all high in

monounsaturated fats.

Lower Cholesterol and Other Benefits

This study looked at several indicators for heart disease, such

as HDL (good) and LDL (bad) cholesterol levels and blood

clotting factors. Both low-fat diets and diets high in

monounsaturated fats lowered LDL cholesterol levels.

The low-fat diet, however, lowered good cholesterol

levels and even increased other indicators for heart

disease such as fibrinogen levels. Fibrinogen levels,

when elevated, are associated with increased blood

clotting, which can lead to a heart attack or stroke.

"Both diets reduce the bad cholesterol comparably, but

monounsaturated fat doesn't lower good cholesterol

levels and it does not raise triglycerides [fat levels],"

says Dr. Kris-Etherton.

Desirable Fat, More Choices

For years we've heard health claims about olive oil--an

oil high in monounsaturated fats. Studies have shown

that these unsaturated fats have positive effects on

cholesterol levels. Now it may be time for peanuts to

have their moment of glory.

"Peanuts and peanut oil needed to be tested, as well.

People may be avoiding the peanuts because of fat, but

like olive oil, they are also high in monounsaturated

fats," says Dr. Kris-Etherton. The study, funded by the

Peanut Institute, set out to discover if peanuts and

peanut oil were as good as olive oil.

"Our data fits beautifully with other data," adds Dr.

Kris-Etherton. "Peanuts could be used as a source of

monounsaturated fat. The result is more options and

more sources of monounsaturated fat, so that we have

flexibility with diet planning. This makes it easier, with

more sources of a desirable fat."

Replace the Fat, Don't Add to It

But this doesn't mean you should go nuts over peanuts.

You have to watch your serving sizes. In this study, each

person consumed three servings per day: A serving was

1 ounce of peanuts or 2 tablespoons of peanut butter.

"You can't just open the jar and start spooning out the

peanut butter," Dr. Kris-Etherton cautioned. The key is

replacing, not adding to, the fat in your diet with

monounsaturated fats. Since fat is such a concentrated

source of calories, if you just add fat to the diet, you're

also likely to gain weight and erase any favorable

effects of peanuts on your cholesterol or your risk of

heart attack.

Know Your Fats

Finally, know your fats. Understand the sources of fat

and amount of fat in your diet. The peanuts in the

peanut butter may contribute to a healthy heart, but the

added hydrogenated oils in some peanut butters do not.

In fact, partially hydrogenated oils may be worse for

your cholesterol than saturated fat! Check your food

ingredient labels and always eat wisely.

Reviewer: Beth Israel Deaconess Medical Center. Reviewed for medical accuracy by physicians at Beth Israel Deaconess Medical

Center (BIDMC), Harvard Medical School. BIDMC does not endorse any products or services advertised on this Web site.