Consuming more nuts appears to be associated with improvements in blood cholesterol¹（胆固醇） levels, according to a pooled analysis of data from 25 trials reported in the May 10 issue of Archives（档案，案卷） of Internal Medicine, one of the JAMA/Archives journals. "Dietary interventions²（干预，干涉） to lower blood cholesterol concentrations and to modify blood lipoprotein（脂蛋白） levels are the cornerstone（基础，柱石） of prevention and treatment plans for coronary heart disease," the authors write as background information in the article. "Recently, consumption of nuts has been the focus of intense research because of their potential to reduce coronary heart disease（冠心病） risk and to lower blood lipid [fat and cholesterol] levels based on their unique nutritional³ attributes." Nuts are rich in plant proteins, fats (especially unsaturated fatty acids不饱和脂肪酸), dietary fiber⁴, minerals, vitamins and other compounds, such as antioxidants（抗氧化剂） and phytoesterols.

Joan Sabaté, M.D., Dr.P.H., of Loma Linda University, Loma Linda, Calif., and colleagues pooled primary data from 25 nut consumption trials conducted in seven countries and involving 583 women and men with high cholesterol or normal cholesterol levels. All the studies compared a control group to a group assigned to consume nuts; participants were not taking lipid-lowering medications（药物治疗） .

Participants in the trials consumed an average of 67 grams (about 2.4 ounces) of nuts per day. This was associated with an average 5.1 percent reduction in total cholesterol concentration, a 7.4 percent reduction in low-density lipoprotein (LDL, or "bad" cholesterol) and an 8.3 percent change in ratio of LDL cholesterol to high-density lipoprotein (HDL, or "good" cholesterol). In addition, triglyceride（甘油三酸脂） levels declined by 10.2 percent among individuals with high triglyceride levels (at least 150 milligrams per deciliter分升), although not among those with lower levels.

"The effects of nut consumption were dose related, and different types of nuts had similar effects on blood lipid levels," the authors write. "The effects of nut consumption were significantly modified by LDL-C, body mass index and diet type: the lipid-lowering effects of nut consumption were greatest among subjects with high baseline LDL-C and with low body mass index and among those consuming Western diets."

The results support the inclusion of nuts in therapeutic⁵ dietary interventions for improving blood cholesterol levels, they conclude. "Nuts are a whole food that have been consumed by humans throughout history. Increasing the consumption of nuts as part of an otherwise prudent⁶（谨慎的，节俭的） diet can be expected to favorably affect blood lipid levels (at least in the short term) and have the potential to lower coronary heart disease risk."