Nut consumption cuts risk of cardiovascular disease
Consumption of peanuts, walnuts and tree nuts appears to reduce the risk of coronary heart disease (CHD) and cardiovascular disease (CVD), according to recent large prospective cohort studies.
“[W]e observed that nut consumption was associated with lower risk of developing CVD after adjusting for cardiovascular risk factors. As compared with those participants who never or almost never consumed nuts, those who consumed nuts five or more times per week had 14-percent lower risk of CVD and 20-percent lower risk of CHD,” said researchers.
Information from three different prospective cohort study populations were used for the present analysis: 76,364 females from the Nurses’ Health Study, 92,946 females from the Nurses’ Health Study II and 41,526 males from the Health Professionals Follow-Up Study. None of the participants had cancer at baseline.
Based on a semiquantitative food-frequency questionnaire, patients were grouped according to nut consumption categories: frequency (never or almost never, less than once per week, once per week, two to four times per week or five or more times per week) and type of nut (total nuts, peanuts, tree nuts, walnuts or peanut butter).
Over a total of 5,063,439 person-years of follow-up across all three cohorts, 14,136 CVD events were reported, of which 8,390 were CHD and 5,910 were stroke cases. [J Am Coll Cardiol 2017;70:14-21]
Multivariable analysis revealed a significant inverse association, with those consuming one serving of nuts five or more times per week showing significantly lower risks of total CVD (hazard ratio [HR], 0.86; 95 percent CI, 0.79 to 0.93; p=0.0002 for trend) and CHD (HR, 0.80; 0.72 to 0.89; p<0.0001 for trend) than those who never or almost never ate nuts.
Fatal (HR, 0.76; 0.70 to 0.84; p=0.0003) and nonfatal (HR, 0.91; 0.85 to 0.98; p=0.005) CVD were also inversely associated with total nut consumption frequency.
Moreover, each serving increase of nuts was associated with a 6-percent and 13-percent drop in the risk of total CVD (HR, 0.94; 0.89 to 0.99) and CHD (HR, 0.87; 0.81 to 0.94), respectively. In contrast, nut consumption frequency did not significantly impact the risk of stroke (HR, 0.98; 0.86 to 1.13; p=0.88 for trend).
Consumption by type of nut was also associated with the risk of CVD, with total nuts (HR, 0.86; 0.81 to 0.91), peanuts (HR, 0.87; 0.82 to 0.93), tree nuts (HR, 0.85; 0.79 to 0.91) and walnuts (HR, 0.81; 0.72 to 0.92) all significantly lowering the risk of CVD.
The risk of CHD was likewise reduced by consumption of total nuts (HR, 0.81; 0.75 to 0.87), peanuts (HR, 0.85; 0.79 to 0.92), tree nuts (HR, 0.77; 0.70 to 0.84) and walnuts (HR, 0.79; 0.66 to 0.94). Peanut butter consumption was not associated with any of the CVDs examined and the type of nut consumed had no significant impact on the risk of stroke.
“There are several mechanisms that may account for the inverse associations between nut consumption and CVD,” said researchers, adding that improvements in lipid profiles, inflammation, endothelial function, insulin resistance and oxidative stress have been attributed to nuts across several studies.
“Nuts are also rich in polymerized polyphenols, which provide a substrate for gut microbiota. The compounds arising from this metabolism may modulate gut microbiota through prebiotic effects and antimicrobial activities and consequently contribute to cardiovascular benefits for the host,” they said. [Food Sci Nutr 2017;57:3154-3163]