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Eat range of unpeeled raw nuts to benefit heart, urge experts

People who regularly eat variety of nuts have lower risk of CHD and cardiovascular disease

Louise Prime

Tuesday, 14 November 2017

A variety of unpeeled and unprocessed raw nuts should be included in the diet to promote cardiovascular health, researchers have urged. Experts said the large long-term study,* published in the Journal of the American College of Cardiology, “strongly suggests an association between nut consumption and heart disease protection”.

The research team pointed out that many guidelines have moved recently towards recommending largely plant-based diets, with the inclusion of nuts because of their “unique nutritional composition” and reported association with reduced cardiovascular risk factors. But, they said, previous studies on this theme have tended to focus on overall nut consumption whereas they wanted to examine whether benefits varied between specific types of nuts.

They analysed up to 32 years’ follow up data on more than 210,000 participants in the Nurses’ Health Study, Nurses’ Health Study II, and the Health Professionals Follow-up Study. In all three groups, information about medical history, lifestyle and health conditions were collected via self-administered questionnaires every two years.

The researchers looked at the association between major cardiovascular events and people’s consumption of peanut butter, peanuts, walnuts and tree nuts; they explained that they included peanuts, which are not nuts but legumes, because they have a similar fatty acid and nutrient profile to that of other nuts.

During follow up, there were 14,136 cardiovascular disease cases recorded, including 8,390 coronary heart disease (CHD) cases and 5,910 stroke cases.

The researchers found a consistent inverse association between total nut consumption and total cardiovascular disease and CHD. They also reported that compared with people who never consumed nuts, those who ate walnuts at least once a week had a 19% lower risk of cardiovascular disease and 21% lower risk of CHD. Eating peanuts or tree nuts at least twice a week was associated with a 13% and 15% lower risk of cardiovascular disease, respectively; and a 15% and 23% lower risk of CHD.

Participants who consumed five or more servings of nuts a week had a 14% lower risk of cardiovascular disease and a 20% lower risk of CHD than those who never or almost never consumed nuts. The study authors said their results were similar when accounting for consumption of tree nuts, peanuts and walnuts individually. They said they found no evidence of an association between total nut consumption and risk of stroke, but eating peanuts and walnuts was inversely associated with the risk of stroke. Peanut butter and tree nuts were not associated with stroke risk.

They noted that as diet was self-reported, errors “are inevitable”, but concluded: “Our findings support recommendations of increasing the intake of a variety of nuts, as part of healthy dietary patterns, to reduce the risk of chronic disease in the general populations.”

The author of an accompanying editorial** said the consistency of the study findings strongly suggests an association between nut consumption and heart disease protection, although there is more to research.

He added: “Ideally, further investigations should test the effects of long-term consumption of nuts supplemented into the usual diet on hard cardiometabolic events. In the meantime, raw nuts, if possible unpeeled and otherwise unprocessed, may be considered as natural health capsules that can be easily incorporated into any heart-protective diet to further cardiovascular well-being and promote healthy ageing.”

* Guasch-Ferré M, Xiaoran Liu, Malik VS, et al. Nut consumption and risk of cardiovascular disease. Journal of the American College of Cardiology, Nov 2017, 70 (20) 2519-2532. DOI: 10.1016/j.jacc.2017.09.035.

** Ros E. Eat nuts, live longer. Journal of the American College of Cardiology, Nov 2017, 70 (20) 2533-2535. DOI: 10.1016/j.jacc.2017.09.1082.

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