The researchers noted that previous studies have shown that peanuts may have a beneficial effect on cardiovascular disease. For the latest study, they set out to look not at stroke risk specifically, but at how peanut consumption is linked to various forms of cardiovascular disease and cardiovascular events, such as a stroke or heart attack. They did this by looking at data from 74,793 people ages 45 to 74 who completed a lifestyle and diet questionnaire as part of the Japan Public Health Center-based Prospective Study. Participants were followed in two different sets, or cohorts — one from 1995 to 2009, and one from 1998 or 1999 to 2012. Peanut consumption was estimated for each participant based on their answers on a food-frequency questionnaire, and data on cardiovascular disease and events during the follow-up period was taken from health records.
To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletters!
Peanut consumption linked to reduced cardiovascular disease
During a median follow-up period of 14.8 years, there were 3,599 reported cases of stroke and 849 reported cases of ischemic heart disease (caused by reduced blood flow). After adjusting for a number of factors — including age, sex, location, smoking status, alcohol consumption, physical activity, and dietary patterns other than peanut consumption — the researchers found that people who consumed the most peanuts were less likely to have cardiovascular disease in general, an ischemic stroke, or any type of stroke (including a hemorrhagic stroke, caused by a bleed).
Specifically, participants in the top quarter of peanut consumption — compared with those in the bottom quarter — were 20% less likely to have an ischemic stroke, 16% less likely to have any type of stroke, and 13% less likely to have cardiovascular disease in general. They were also found to be 7% less likely to have a hemorrhagic stroke and 3% less likely to have ischemic heart disease, but these differences weren’t large enough to reach statistical significance. For all of the observed differences, the trends were similar in men and women.
This study represents the first time peanut consumption has been linked to a lower ischemic stroke risk in an Asian study population, according to a Healio article on the study. This is important because many studies on diet and cardiovascular disease in Western countries, including the United States, have low numbers of participants of Asian descent — and because eating peanuts and tree nuts isn’t as common in most Asian countries as in many others. Another important finding from the latest study is that participants in the highest quarter of peanut consumption weren’t actually eating large quantities of peanuts — they consumed an average of just 4.3 peanuts per day, compared with an average of 0 in the lowest quarter. The average peanut intake among all participants was just 1.5 peanuts per day.
It’s unknown why, exactly, eating peanuts might help prevent stroke and cardiovascular disease. They might contain components that are particularly beneficial, including healthy forms of fat, but there could also be a simpler explanation — that they tend to replace less healthy foods in people who eat them. More research is needed to learn what foods peanuts or tree nuts tend to replace in people who eat them, and how this affects the risk for stroke and cardiovascular disease. Future studies could also look at whether consuming larger quantities of peanuts than just a few each day could have an even more beneficial effect on stroke and cardiovascular disease risk.