Dear Doctor: Will eating nuts really reduce my risk of heart disease, cancer and other diseases, which a new study has suggested? If so, how many should I be eating?
Dear Reader: Nuts are fruits. They consist of a hard shell and an edible seed. To answer your question, I'll use the definition of nuts to refer to the varieties we typically eat, although some, like the peanut, are not truly nuts. Nuts are a good source of fiber and contain antioxidants such as vitamin E, healthy polyunsaturated fats and magnesium. These aspects of nuts could reduce the risk of vascular disease and cancer and possibly rates of diabetes.
A 2013 study published in the New England Journal of Medicine looked at nut intake per week among both male and female health professionals. The researchers followed 173,000 people for a period of 30 years and looked at how many of those people died. They found a marked decrease in death rates among those study participants who ate nuts. They also found that the benefit was dose-dependent, meaning that the more nuts people ate per week, the smaller their chance of death during the study period. Compared to people who rarely ate nuts, those who ate nuts once per week had an 11 percent decrease in death rate, while those who ate nuts daily had a 20 percent decrease in death rate.
A much larger recent study, published in the journal BMC Medicine, combined multiple studies and looked at rates of death from heart attacks, strokes and cancer. The studies were from the United States, Europe, Asia and Australia and included a total of more than 819,000 participants. The study quantified the benefits of nuts by the number of servings per day.
The study authors found a 19 percent decrease in death rates among people who were high nut consumers compared to people who were low nut consumers, with a 24 percent decrease in heart disease, an 11 percent decrease in stroke and an 18 percent decrease in cancer. The authors also found that the greatest benefit was seen among those who consumed at least 15 grams to 20 grams of nuts five or six days per week. These results appear to support the findings in the New England Journal study.
So how many nuts is 15 to 20 grams? About 14 almonds, four Brazil nuts, 11 cashews, 12 hazelnuts, nine walnut halves, 29 pistachios and 18 peanuts.
That's not a lot. I'm not suggesting that you precisely count the number of nuts that you eat at any given time, but I would suggest that you eat nuts frequently, perhaps as a snack. I have them on my desk at work. They're much better for you than the unhealthy, high-sugar, high-carbohydrate snacks that can lead to obesity, diabetes and higher death rates. Nuts are high-energy snacks that provide a more sustained suppression of hunger than sugary snacks.
If you don't eat nuts already, start slowly. You may like some more than others, and you may tolerate some better than others. In any case, have some nuts; they're good for you.
(Send your questions to firstname.lastname@example.org, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)