Which is a heart-healthier choice for a snack: a package of nuts, a chocolate bar, a package of pretzels or a bag of chips? In the past, the answer would have been pretzels or none of the above. The reason? Pretzels were lowest in fat. Recent evidence, however, is pointing to nuts as the better choice. Why? Because of the type of fat, and possibly the type of carbohydrates and fiber, found in nuts.
Although more than 70 percent of the calories in most nuts come from fat, much of this fat is in the form of monounsaturated and polyunsaturated fat rather than saturated fat. Saturated fats are those most associated with increasing the risk of heart disease. In the past, monounsaturated fats were thought to have a neutral effect on heart disease risk. Today, the more common opinion is that they may have a positive effect.
So far, five large prospective cohort studies (the Adventist Health Study, the Iowa Women Health Study, the Nurses’ Health Study, the Physicians’ Health Study and the CARE Study) have examined the relationship between nut consumption and the risk of coronary heart disease, and all have found higher nut consumption to be associated with lower risk of heart disease. In addition, several clinical studies have found heart-healthy diets containing various nuts or peanuts to be beneficial in lowering total and low-density lipoprotein (LDL) cholesterol in study participants.
Just how healthy are nuts? In the Nurses’ Health Study, 86,000 women were followed over a 14-year period. Researchers found that the women who ate the most nuts, more than half a cup per week, were about 35 percent less likely to develop heart disease or suffer a heart attack than women who rarely or never ate nuts. Further, the relationship between nut consumption and heart disease held true even after controlling for differences in exercise, smoking, body weight and fiber or vitamin intake. Likewise, in the Physicians’
Health Study of 22,000 men over a period of 11 years, men whose diets included the most nuts had the lowest risk of dying from heart disease during the study. Again, researchers took care to look at nut consumption independent of other factors like exercise, high blood pressure, smoking and diabetes.
While the reasons for these findings are still somewhat unclear, most researchers are pointing to the favorable fatty acid profile of nuts (high in unsaturated fatty acids and low in saturated ones) as the major contributor to the cholesterol-lowering effects seen and therefore the lower risk of heart disease. Scientists are also eyeing the magnesium, vitamin E and fiber content of nuts as possible factors. Magnesium, for example, is an important mineral in proper heart muscle function.
The bottom line? There is good evidence to suggest that replacing foods high in saturated fats with a handful of nuts may be a good choice. However, it’s important to remember that whether unsaturated or saturated, fats pack in a whopping nine calories per gram. Because of their high fat content, nuts are rich sources of calories. Most types provide around 100 calories per ounce (approximately two tablespoons). If you don’t want your scales to creep up, it’s best not to add nuts to an already calorie-laden day. Instead, replace other high-fat foods in your diet with a serving of nuts. The next time you choose a snack at the convenience store, go for a package of nuts over chips, donuts or cookies.