MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Although previous evidence has shown that frequent nut consumption is associated with reduced cardiovascular risk factors including dyslipidaemia, type 2 diabetes and metabolic syndrome; as well as with lower risk of coronary heart disease (CHD); most of the previous prospective studies have focused on total nut consumption in relation to the risk of CVD. However, the associations between peanut butter and specific types of nuts, such as peanuts and walnuts, with major cardiovascular events, and specifically the relation with stroke were unclear. Of note, because the nutritional composition of peanuts and walnuts differs from other nuts, it was of particular interest to evaluate the health effects of specific types of nuts. Therefore, our main aim was to look at several types of nuts including total nut consumption, peanuts, walnuts, and tree nuts.
Briefly, in three large prospective cohorts with up to 32 years of follow-up, people who regularly eat nuts, including peanuts, walnuts and tree nuts, have a lower risk of developing cardiovascular disease or coronary heart disease compared to people who never or almost never eat nuts. We found a consistent inverse association between total nut consumption and total cardiovascular disease (14% lower risk for those consuming nuts five or more times per week) and coronary heart disease (20% lower risk).
Also, after looking at individual nut consumption, eating walnuts one or more times per week was associated with a 19 percent lower risk of cardiovascular disease and 21 percent lower risk of coronary heart disease. Participants who ate peanuts or tree nuts two or more times per week had a 15 percent and 23 percent, respectively, lower risk of coronary heart disease compared to those who never consumed nuts.