In a recent issue of Nutrition Reviews, researchers from Penn State University report that regularly eating nuts significantly reduces the incidence of coronary artery disease.
The researchers, led by Dr. Penny Kris-Etherton, distinguished professor of nutrition, conducted a formal review of 16 studies that have been conducted over the years examining the question of whether nuts can help prevent heart disease. They concluded that, based on this large amount of available data, eating an ounce of nuts more than five times a week can reduce the risk of coronary artery disease by an astounding 25 – 39%. (An ounce is 3 – 4 tablespoons of nuts.)
The investigators were not able to characterize whether specific types of nuts were better than others at protecting from heart disease, but virtually every variety of nut was consumed by people participating in these studies. It is thought that peanuts (technically not a nut but a legume) accounted for at least 50% of the nuts consumed in these studies, however.
There are several reasons nuts may be useful in protecting from coronary artery disease. Nuts contain a lot of unsaturated fatty acids, and are low in saturated fatty acids. Saturated fatty acids are a major cause of high cholesterol, and substituting unsaturated for saturated fatty acids in the diet has long been recommended as part of a cholesterol-lowering diet. Thus, nuts appear to help lower cholesterol levels.
Nuts also contain the antioxidant vitamin E, folic acid (which reduces homocysteine levels) and plant fiber (which can reduce cholesterol levels). In addition, nuts contain arginine, which is a precursor to nitric acid, a substance made in the walls of blood vessels that relaxes the blood vessels and prevents clotting. Walnuts, in particular, contain alpha-linolenic acid, which is a precursor of omega-3 fatty acid, which is thought to protect against heart disease.
As noted, peanuts are not technically nuts. But they were linked to the same health benefits as the “real” nuts in these studies.
Precautions:
Nothing is free in this world. While nuts may be good for you, they have a few drawbacks that should be taken into account:- Nuts are loaded with calories. A handful of nuts contains about 150 calories. So, while nuts should be strongly considered in a heart healthy diet, they shouldn’t be added, they should be substituted for another source of calories. Otherwise, the benefits of eating nuts might be negated by your expanding waistline.
- Brazil nuts contain a relatively large amount of saturated fats, and should not be selectively added to the diet.
How to add nuts to your diet sensibly:
- Don’t just add nuts to your diet; to avoid obesity substitute nuts for something else. Good candidates for foods you can profitably displace from your diet with a tablespoon or two of nuts are: potato chips, butter, candy, ice cream, and any processed food (most of which are loaded with saturated fats.)
- Add some nuts to your salad, pasta dishes, and fish dishes.
- Choosing cereals that contain nuts makes sense, but make sure the cereal isn’t clogged up with saturated fats or trans fatty acids (as much processed cereal is.) Read the labels. (You’re looking for the phrase “hydrogenated” or “partly hydrogenated” oils. If you see that phrase, visualize a skull and crossbones.)
