Daily walnut consumption lowers total cholesterol, LDL at 2 years
Healthy older adults who consumed walnuts daily for 2 years experienced reductions in total cholesterol and LDL, as well as small and total LDL particles, according to results of the WAHA trial.
Emilio Ros, MD, PhD, director of the Lipid Clinic, Endocrinology and Nutrition Service at Hospital Clínic of Barcelona, Spain, said in a press release that previous research had shown that nuts, in general, and walnuts, in particular, were 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,” Ros said.
Ros and colleagues conducted the two-center randomized controlled WAHA trial to test a walnut-supplemented diet in 708 cognitively healthy adults aged 63 to 79 years without major comorbidities.
Patients received a walnut-free or walnut-supplemented diet, with their compliance, tolerance, medication changes and body weight recorded during visits, which occurred every 2 months. Those in the walnut-supplemented group received 8-week allotments of raw, pieced walnuts at this time.
Primary care physicians supervised participants and modified medications, including lipid-lowering drugs, according to their assessment of risk factor levels.
In all, 636 participants completed the study and 628 had full data for lipoprotein analyses (mean age, 69 years; 67% women; 32% treated with statins).
Data revealed that the walnut diet significantly lowered total cholesterol by 4.4% (mean, –8.5 mg/dL; 95% CI, –11.2 to –5.4), LDL by 3.6% (mean, –4.3 mg/dL; 95% CI, –6.6 to –1.6) and intermediate-density lipoprotein cholesterol by 16.8% (mean, –1.3 mg/dL; 95% CI, –1.5 to –1); triglycerides and HDL were not affected.
In addition, walnut consumption reduced total LDL particles by 4.3% and small LDL particle number by 6.1%. The researchers also reported sex-based differences, with the walnut diet reducing LDL by 7.9% in men and 2.6% in women (P for interaction = .007).
“Thanks in part to statin treatment in 32%, the average cholesterol levels of all the people in our study were normal,” Ros said in the release. “For individuals with high blood cholesterol levels, the LDL cholesterol reduction after a nut-enriched diet may be much greater.”
Ros also said in the release that 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. Our study found that the healthy fats in walnuts did not cause participants to gain weight.”