By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Much of what we have learned about the effects of different diets on heart disease has come from the Nurses’ Health Study. In this study more than 100,000 US nurses have provided detailed information about their eating habits in 1980 and 1984. Since then their health has been followed at regular intervals. One of the questions they were asked was to describe their intake of nuts, which are an important ingredient of the Mediterranean diet.

The main finding was that women who ate at least one ounce of nuts or one tablespoon of peanut butter five or more times a week had about a 35 per cent lower risk of having a heart attack than women who rarely ate nuts. Although the women who ate nuts had a generally more healthy lifestyle (they smoked less, exercised more and were thinner than the others), none of these factors could explain their lower rate of heart disease. Only 5 per cent of the women in the study ate nuts more than 5 times a week.

Doctor’s comments

This is not the first study to show a beneficial effect of eating nuts. Seventh Day Adventists also have a high consumption and also have relatively little heart disease.

Although nuts have a high fat (and hence calorie) content, the fat is mostly unsaturated, which has a beneficial effect on blood lipids. Experiments in which people have been fed diets rich in nuts such as walnuts or almonds have shown a reduction in blood cholesteroil levels. Other potentially beneficial ingredients in nuts include magnesium, vitamin E, fiber and potassium.

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