a new study has found that five or more servings of walnuts per week may lower the risk of death from cardiovascular disease by 25 per cent among older adults and increase life expectancy by over a year compared to those who just say no to the nutritious nuts.the research,
published in the journal nutrients, found that five ounces of walnuts per week imparted the greatest health benefits and may even decrease the risk of death from any cause by 14 per cent.“what we’ve learned from this study is that even a few handfuls of walnuts per week may help promote longevity, especially among those whose diet quality isn’t great to begin with,”
said yanping li, lead investigator of the study and senior research scientist at the department of nutrition at harvard t.h. chan school of public health.“it’s a practical tip that can be feasible for a number of people who are looking to improve their health, which is top of mind for many people.”li’s research was supported by the
california walnut commission — which had no role in the design and conduct of the study — found that two-to-four one-ounce servings per week was associated with a 13 per cent drop in the risk of all-cause death, a 14 per cent reduction in the risk of death from cardiovascular causes and a one-year increase in life expectancy compared to those who don’t partake.the health benefits extended to people with less than ideal diets (as determined by a validated index of foods associated with the risk of chronic disease), with a one half-ounce increase in walnuts per day tied to a 12 per cent drop in all-cause death and 13 per cent reduction in death from cardiovascular disease.“nuts are nutrient-dense foods rich in unsaturated fats, proteins, vitamins, minerals and fibres,” the study said. “consumption of nuts is associated with a lower risk of cardiovascular diseases,
obesity and type 2
diabetes in different populations from varying regions. compared to other nuts (i.e., almonds, hazelnuts, pistachio) that are rich sources for monounsaturated fatty acids, walnuts contain high content of alpha-linolenic acid, a plant-based omega-3 fatty acid, which might confer them additional antiatherogenic properties through improving blood lipids and endothelial function.”the prospective observational study relied on the data from 67,014 women included in the nurses’ health study (average age 63.6 years) and 26,326 men from the health professionals follow-up study (average age 63.3) beginning in 1986. subjects — who were relatively healthy and free of disease at the outset — were followed for roughly 20 years with dietary intake and lifestyle factors (such as physical fitness and smoking status) evaluated every four years.
the prolonged period of study allowed researchers to reach conclusions about the relationship between walnut intake, cardiovascular disease and longevity, but because the research was observational in nature, the study reveals correlation — not causation. the work also had several limitations, including using self-reporting as a means of determining walnut consumption — a method that may introduce measurement error. relying on pools of health professionals may also limit the ability to extrapolate findings to larger populations.the study found that subjects who were more inclined to eat walnuts also tended to be more physically active, eat better, drink less alcohol and take vitamins — other factors that influence life expectancy — but researchers said they controlled for these associations in their analysis, allowing them to conclude that consuming walnuts was worth every ounce of the effort.“our findings suggest that incorporating walnuts in diet may potentially contribute to improving overall dietary quality that has been associated with increases in life expectancy among adults in the u.s. and other countries.”
dave yasvinski is a writer with healthing.ca
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