Health Benefits of Nuts

By Donald R. Hall, DrPH, CHES

You've probably heard, "You shouldn't eat nuts, they are high in fat." That idea came from the out-of-date view that "all fats are bad." It's now known that while animal fats contribute to heart disease, healthy fats, as found in nuts, actually reduce the risk of heart attack.

The first study to show this affect was a study of 31,208 Adventists where they found that those who ate nuts one to four times each week had a 27 percent reduced risk of dying from heart disease compared to those who ate nuts less than once per week. Those who ate nuts five or more times each week cut their risk of death from heart disease in half (48 percent reduction) even after adjusting for standard risk factors such as age, smoking, exercise, high blood pressure, and seven other foods including meat, cheese, legumes, and fruit. Later research on the same group showed that those who ate nuts daily lived nearly three years longer on the average than those who seldom ate nuts.

The Nurse's Health Study, including 86,016 women followed for 14 years, showed similar results. Those women who ate five or more ounces of nuts a week reduced their risk of death from heart attacks by 35 percent. This reduction continued even after adjusting for obesity, blood pressure, exercise, smoking, alcohol, vitamin E, dietary fats, dietary fiber, red meat, and fruit and vegetable intake. In nonsmokers and nondrinkers (of alcohol) the frequent nut users reduced their risk by 52 percent.

In the Iowa Women's Health Study, women who ate nuts frequently, compared to those who seldom ate nuts, reduced their risk of fatal heart disease by 57 percent. Here are a few of the reasons researchers believe nuts are good for your health:

• Although nuts are high in fat, the fat is mostly unsaturated fat which has a beneficial effect on health.
• Studies with almonds and walnuts have both shown a beneficial effect on blood cholesterol levels.
• The protein in nuts is high in arginine, a precursor to nitric oxide which is important to help keep blood vessels relaxed and open and helps prevent clotting.
• Walnuts in particular, are high in alpha-linolenic acid, an essential (n-3 or omega) fatty acid that is protective to the heart and circulation. This fat has been shown to reduce the risk of heart disease and fatal arrhythmias in various studies.
• Nuts are also good sources of dietary fiber, magnesium, copper, folic acid, vegetable protein, potassium, and vitamin E, all of which have been shown to be important for heart health.

Some people have been hesitant to eat nuts thinking that because they are high in fat, they may cause obesity. This concern was looked at in the Adventist health study. They found that nuts provide satiety or satisfaction to a meal and that those who frequently ate nuts were actually more lean than those who didn't eat nuts. If you have the trouble of getting stopped when eating nuts, buy your nuts in the shell. Cracking them slows you down and should prevent you from eating too many.

When peanuts were looked at separately from the rest of the nuts (peanuts are really a legume) they also showed protective effects. Peanut butter, however, was only weakly protective. This is most likely due to the fact that most peanut butter has hydrogenated fats added. If you choose the unhydrogenated or "old fashioned" peanut butter, where the oil rises to the top, you should get all the benefits of real nuts.

For optimal health enjoy a variety of nuts and seeds daily: walnuts, hazelnuts, Brazil nuts, filberts, almonds, cashews, peanuts, sunflower seeds, sesame seeds, flax seed, and unhydrogenated nut butters such as peanut butter, almond butter, and tahini. Add nuts to salads, stir fry, and toppings on desserts. An ounce each day is a good goal. Raw or roasted, it doesn't seem to matter. Enjoy!

Sources:

1. Gary Fraser, et al, A possible protective effect of nut consumption on risk of coronary heart disease, the Adentist Health Study, Archives of Internal Medicine 152:1416-1424, July 1992.

2. Frank Hu, et al, Frequent nut consumption and risk of coronary heart disease in women, British Medical Journal 317:1341-5, Nov. 14 1998.

3. Prineas RJ, et al, Walnuts and serum lipids, New England Journal of Medicine, 1993;328:603-7.

Reprinted with permission from Wellsource.