Eating
regular variety of nuts
associated with lower risk of heart disease
American College of
Cardiology
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, according to a study published in the Journal
of the American College of Cardiology. The study is the largest to date looking at frequency of nut consumption in relation to incident cardiovascular disease.
Recently, dietary
recommendations have shifted toward diets including higher quantities of plant-based
foods over animal-based foods, with most dietary patterns including nuts
because of their association with reduced cardiovascular risk factors and
unique nutritional composition.
While many past
studies focused on nut consumption as a whole, researchers in this study also
looked at the association between specific types of nuts -- peanut butter,
peanuts, walnuts and tree nuts -- with major cardiovascular events.
Peanuts were included even though they are actually a legume because they have a similar fatty acid and nutrient profile as other nuts.
Peanuts were included even though they are actually a legume because they have a similar fatty acid and nutrient profile as other nuts.
The study looked at
over 210,000 people, including women from the Nurses' Health Study and Nurses'
Health Study II and men from the Health Professionals Follow-up Study, with up
to 32 years of follow up.
In all three groups, information about medical history, lifestyle and health conditions were collected via self-administered questionnaires every two years.
In all three groups, information about medical history, lifestyle and health conditions were collected via self-administered questionnaires every two years.
The primary endpoint
of the study was major cardiovascular disease, defined as a combined endpoint of
myocardial infarction, stroke or fatal cardiovascular disease.
Secondary endpoints were total coronary heart disease, defined as fatal or non-fatal myocardial infarction, and total stroke, which included all fatal and non-fatal strokes. Researchers documented 14,136 cardiovascular disease cases, including 8,390 coronary heart disease cases and 5,910 stroke cases.
Secondary endpoints were total coronary heart disease, defined as fatal or non-fatal myocardial infarction, and total stroke, which included all fatal and non-fatal strokes. Researchers documented 14,136 cardiovascular disease cases, including 8,390 coronary heart disease cases and 5,910 stroke cases.
The study found a
consistent inverse association between total nut consumption and total
cardiovascular disease and coronary heart disease.
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 13 percent and 15 percent lower risk of cardiovascular disease, respectively, and a 15 percent and 23 percent, lower risk of coronary heart disease, respectively, compared to those who never consumed nuts.
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 13 percent and 15 percent lower risk of cardiovascular disease, respectively, and a 15 percent and 23 percent, lower risk of coronary heart disease, respectively, compared to those who never consumed nuts.
Participants who consumed
five or more servings of nuts a week had a 14 percent lower risk of
cardiovascular disease and a 20 percent lower risk of coronary heart disease
than participants who never or almost never consumed nuts.
The results were similar when accounting for consumption of tree nuts, peanuts and walnuts individually.
Researchers 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.
The results were similar when accounting for consumption of tree nuts, peanuts and walnuts individually.
Researchers 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.
"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," said Marta Guasch-Ferre, PhD, lead author of the
study and research fellow at the department of nutrition at Harvard T.H. Chan
School of Public Health.
Several limitations
were noted in the study, including that the sample size was limited to white
health professionals.
However, the researchers note that the results can be generalized to men and women of different ethnicities because there is no reason to expect the underlying mechanisms to be different.
Also, because the nut intake was self-reported, errors are inevitable, and there was not data on how the nuts were prepared, so the influence of preparation methods was not able to be tested.
However, the researchers note that the results can be generalized to men and women of different ethnicities because there is no reason to expect the underlying mechanisms to be different.
Also, because the nut intake was self-reported, errors are inevitable, and there was not data on how the nuts were prepared, so the influence of preparation methods was not able to be tested.
In an accompanying
editorial comment, Emilio Ros, MD, PHD, of the Endocrinology and Nutrition
service at the Hospital Clínic in Barcelona and investigator of CIBEROBN, a
research network of Instituto de Salud Carlos III, Spain, confirmed that the
consistency of the findings strongly suggests an association between nut
consumption and heart disease protection, but there is more to research.
"Ideally, further investigations should test the effects of long-term consumption of nuts supplemented into the usual diet on hard cardiometabolic events," Ros said. "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 aging."