Healthy older adults who ate a handful of walnuts a day for two years modestly lowered their level of low-density lipoprotein or LDL cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk.
Published: August 30, 2021
Source: American Heart Association
Walnuts are a rich source of omega-3 fatty acids (alpha-linolenic acid), which have been shown to have a beneficial effect on cardiovascular 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.
In a sub-study of the Walnuts and Healthy Aging study, a large, two-year randomised controlled trial examining whether walnuts contribute to healthy ageing, researchers evaluated if regular walnut consumption, regardless of a person's diet or where they live, has beneficial effects on lipoproteins.
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. After two years, participants' cholesterol levels were tested, and the concentration and size of lipoproteins were analysed by nuclear magnetic resonance spectroscopy.
Among key findings of all study participants:
- At 2 years, participants in the walnut group had lower LDL cholesterol levels
- Daily consumption of walnuts reduced the number of total LDL particles by 4.3% and small LDL particles by 6.1%. These changes in LDL particle concentration and composition are associated with a lower risk of cardiovascular disease.
- LDL cholesterol changes among the walnut group differed by sex; in men, LDL cholesterol fell by 7.9% and in women by 2.6%.
Eating a handful of walnuts every day is a simple way to promote cardiovascular health. Many people are worried about unwanted weight gain when they include nuts in their diet," Ros said. "Our study found that the healthy fats in walnuts did not cause participants to gain weight." More research is also needed to clarify the different LDL results in men and women.
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Materials provided by American Heart Association. Content may be edited for style and length.
- Sujatha Rajaram, Montserrat Cofán, Aleix Sala-Vila, Ella Haddad, Mercè Serra-Mir, Edward Bitok, Irene Roth, Tania M. Freitas-Simoes, Amandeep Kaur, Cinta Valls-Pedret, Mónica Doménech, Keiji Oda, Dolores Corella, Joan Sabaté, Emilio Ros. Effects of Walnut Consumption for 2 Years on Lipoprotein Subclasses Among Healthy Elders: Findings From the WAHA Randomised Controlled Trial. Circulation, 2021; DOI: 10.1161/CIRCULATIONAHA.121.054051