An exciting new study was published in late November in the prestigious medical journal The New England Journal of Medicine. In a nut shell the study found that those who ate the most nuts had a lower death rate or a reduced mortality risk. Eating nuts seven or more times per week (that’s a healthy handful daily) had a 20% less chance of dying during the study period than people who didn’t eat nuts. Significant inverse associations were also seen between nut consumption and deaths due to cancer, heart disease, and respiratory disease.
The researchers, from prestigious US medical schools and research institutes, including the Harvard School of Public Health and the Harvard Medical School, studied two groups of subjects from the well-known Nurses’ Health Study and the Health Professional Follow-up Study. This resulted in the largest study ever done on nuts and risk of early death – nearly 115,000 men and women being followed over a 30 year period.
These new results support findings of other important, well-known studies, such as the Adventist Health Study, the Iowa Women’s Health Study, and the recent results of the large PREDIMED Spanish study which found that regular nut eaters have a reduce risk of developing heart disease and diabetes.
The Harvard researchers not only took into account a wide range of other healthy and unhealthy behaviours, like exercising or not smoking, they also tested the idea that it might be a result of other things in their diets, such as eating olive oil, or having less salt. The results still held up – nut eaters still did better.
Other published journal papers analysing the same two groups of people have also found that their nut intake was associated with less weight gain over time. And in this new Harvard study, frequent nut eaters were leaner than those who didn’t eat nuts.
The authors of the study propose that it’s the healthy nutrients in nuts, such as healthy unsaturated fats, protein, fibre, vitamins, minerals and phytochemicals which have heart-protective, cancer-protective effects; these components are also anti-inflammatory and antioxidant, which may play protective roles in many chronic diseases.
A study like this – called an observational study – can’t prove that eating nuts causes a reduced risk of early death, the nut eaters may have had other characteristics that meant they lived longer. Only long-term clinical trials can prove cause and effect. But eating a daily handful of nuts is one strategy to promote good health—and hopefully longer life —that everyone can adopt easily and deliciously.