Effects of walnut oil on lipid profiles in hyperlipidemic type 2 diabetic patients: a randomized, double-blind, placebo-controlled trial

BACKGROUND: The role of herbal medicine is now well documented in preventing and controlling diabetes mellitus. The main aim of this study was to evaluate the effects of walnut oil consumption on lipid profiles of hyperlipidemic patients with type 2 diabetes. METHODS: In a randomized, double-blind, placebo-controlled clinical trial, 100 hyperlipidemic type 2 diabetic patients aged 35–75 years were assigned to receive 15 cc Persian walnut oil or placebo every day for 90 days. The primary outcomes were the lipid profiles. RESULTS: Consumption of walnut oil by type 2 hyperlipidemic diabetic patients resulted in a significant decrease in total cholesterol levels (treatment difference (TD)=−30.04, P<0.001), triglyceride (TG) level (TD=−15.04, P=0.021), low-density lipoprotein (LDL) level (TD=−30.44, P<0.001) and total cholesterol to high-density lipoprotein (HDL) ratio (TD=−0.72, P<0.001) compared to the control group. There was a trend toward increasing HDL level with consumption of walnut oil (TD=2.28, P=0.06). Frequency of patients reaching a LDL level below 100 was higher in the case group (20 vs 0%). CONCLUSIONS: Addition of walnut oil in the daily diet of type 2 diabetic patients improves lipid profiles. Thus, it may be associated with a coronary artery disease risk factor modulation. Also, walnut oil may serve as a helpful natural remedy for hyperlipidemic patients with type 2 diabetes.