While previous studies have linked nut consumption to a lower risk of heart disease, diabetes, and high blood pressure, the earlier research focused mostly on wealthier white people in the US and Europe. This study, with a more ethnically and economically diverse population in the US and China, suggests that nuts can benefit people from a wide variety of backgrounds
“We can now tell people that peanuts are just as good as more expensive tree nuts, and that the benefit isn’t just for white, upper class people, it’s for everybody,” said senior study author Dr Xiao-Ou Shu, a professor of epidemiology at Vanderbilt University School of Medicine in Nashville, in a phone interview.
Shu’s team studied 71,764 people in the southeastern US – mostly low-income, and about two-thirds African-American – and 134,265 residents of Shanghai.
They looked at how many grams of peanuts and other nuts participants ate on an average day and sorted them into five groups ranging from a low of less than 0.95 grams to a high of at least 18.45 grammes. A peanut – which is technically not a nut – weighs about one gramme and there are about 28 peanuts in a one ounce serving.
The Chinese participants ate far fewer nuts than the Americans and in both countries women generally ate less than men. Average daily nut consumption ranged from a low of 1.6 grammes for Chinese women to a high of 16.4 grammes for white men in the US south.
In the American study, half the people were tracked for at least five years. In the Chinese group, half were tracked for six to 12 years. For the Americans, the risk of dying from any cause was 21 percent lower in the group that ate the most peanuts, compared to the group that ate the least. For the Chinese, the risk reduction was 17 percent.
Nuts and peanuts also lowered the risk of death from strokes and heart disease in both study groups, but not the risk of death from cancer or diabetes.