Eating walnuts every day for two years modestly lowers levels of bad cholesterol according to new research published in the American Heart Association’s flagship journal Circulation.
Healthy older adults who ate about half a cup of walnut a day for two years lowered their level of low-density lipoprotein (LDL) cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk.
Walnuts are high in omega-3 fatty acids (alpha-linolenic acid), which have been shown to improve heart health.
“Prior studies have shown that nuts in general, and walnuts in particular, are associated with lower rates of heart disease and stroke. One of the reasons is that they lower LDL-cholesterol levels, and now we have another reason: they improve the quality of LDL particles. For individuals with high blood cholesterol levels, the LDL cholesterol reduction after a nut-enriched diet may be much greater.”
The study was conducted from May 2012 to May 2016 and involved 708 participants between the age of 63 and 79 (68 percent women) who were healthy, independent-living adults residing in Barcelona, Spain, and Loma Linda, California. Participants were randomly divided into two groups: active intervention and control. Those allocated to the intervention group added about a half cup of walnuts to their usual daily diet, while participants in the control group abstained from eating any walnuts.
Participants’ cholesterol levels were measured after two years, and nuclear magnetic resonance spectroscopy was used to examine the content and size of lipoproteins. This improved test allows doctors to more precisely detect lipoprotein characteristics linked to cardiovascular disease risk.
The study’s two-year retention rate was 90 percent. In 632 cases, complete lipoprotein analyses of 628 were available.
The walnut group had lower LDL cholesterol levels after two years, and daily walnut eating lowered the amount of total LDL particles by 4.3 percent and small LDL particles by 6.1 percent. Changes in the concentration and composition of LDL particles are linked to a lower risk of cardiovascular disease.
LDL cholesterol changes among the walnut group differed by sex, in men, it fell by 7.9 percent and in women by 2.6 percent. According to American Heart Association, more research is also needed to clarify the different LDL results in men and women.