Walnuts may be the healthy snack that is the key to a longer life.
A new study by a research team at Harvard University found a link between eating more walnuts and longer life expectancy plus a lower risk of death in adults.
"What we learned from this study is that even a few handfuls of walnuts a week may help promote longevity, especially among those whose diet quality is not good in the first place. This is a practical tip for people looking to improve their health," said lead researcher Yanping Lee of the Harvard School of Public Health. The findings appear in the journal Nutrients.
Researchers report that eating five or more servings of nuts a week may provide the largest increase in life expectancy.
Nutritionists define a handful (about 30 grams) of walnuts as one serving. Eating five or more servings weekly showed a 14% reduction in the risk of death from all causes. The study authors also found a 25% lower risk of death from cardiovascular disease, and a 1.3-year increase in life expectancy compared to people who never eat walnuts.
Meanwhile, eating two to four servings of nuts a week is also quite beneficial.
The study found that it contributes to a 13% lower risk of death from any cause, a 4% lower risk of dying from heart disease and an increase in one year of life.
Even if the rest of the diet has room for improvement, the study authors argue that eating half a serving of walnuts a day can reduce the risk of death from any cause by 12% and the risk of heart disease by 26%.
To arrive at these findings, the research team analyzed data from 67,014 women with an average age of 63.3 who were originally recruited for a health study of nurses. Meanwhile, the study authors also analyzed data on 26,326 older men from another follow-up study of other healthcare professionals. Both groups also completed a survey regarding their nut consumption.
All participants were healthy when the observations began, with researchers testing their diet every four years for about twenty years. With all the information compiled, researchers were able to link nut consumption to life expectancy.
The researchers note that these findings are ultimately observational, so they can’t definitively determine whether walnuts are directly responsible for longer life expectancy. Despite this, research still claims that eating walnuts helps promote a longer life expectancy and a healthier lifestyle. Most people who reported eating lots of walnuts had a healthier overall diet, exercised frequently, took multivitamins and drank alcohol only occasionally.