据国外媒体5月11日报道，最新研究发现，每天吃坚果可有效改善胆固醇水平，降低罹患冠心病风险。
美国加州洛玛连达大学琼－萨巴特博士和同事搜集了25项有关7个国家坚果消费的数据，对583名胆固醇水平各异的男女患者进行了研究。在他们中间，没有一人服用降低胆固醇的药物。研究人员评估的坚果包括杏仁、榛子、美洲山核桃、开心果、核桃、花生等。
在这些实验中，患者每天平均吃67克坚果。结果，他们的胆固醇总体水平平均下降5.1%，低密度脂蛋白(俗称“有害胆固醇”)降低7.4%，低密度脂蛋白与高密度脂蛋白(俗称“有益胆固醇”)之比下降8.3%。此外，三酸甘油脂指数降低10.2%。食用坚果对改善男女患者胆固醇水平的影响相同。
研究还显示，不同类型的坚果对胆固醇水平的影响相同，但是，“低密度脂蛋白、身体质量指数和饮食类型可以显著增强食用坚果的作用：在那些低密度脂蛋白水平高、身体质量指数低以及坚持西餐习惯的参与者当中，食用坚果对降血脂的影响最为明显。”
虽然经常吃坚果看上去具有许多重要健康益处，但由于热量很高，每天吃坚果的数量不应超过85克。研究结果将刊登在最新一期的《内科学文献》（Archives of Internal Medicine）上。
推荐原文出处：
Arch Intern Med. 2010;170(9):821-827.
Nut Consumption and Blood Lipid Levels
Joan Sabaté, MD, DrPH; Keiji Oda, MA, MPH; Emilio Ros, MD, PhD
Background Epidemiological studies have consistently associated nut consumption with reduced risk for coronary heart disease. Subsequently, many dietary intervention trials investigated the effects of nut consumption on blood lipid levels. The objectives of this study were to estimate the effects of nut consumption on blood lipid levels and to examine whether different factors modify the effects.
Methods We pooled individual primary data from 25 nut consumption trials conducted in 7 countries among 583 men and women with normolipidemia and hypercholesterolemia who were not taking lipid-lowering medications. In a pooled analysis, we used mixed linear models to assess the effects of nut consumption and the potential interactions.
Results With a mean daily consumption of 67 g of nuts, the following estimated mean reductions were achieved: total cholesterol concentration (10.9 mg/dL [5.1% change]), low-density lipoprotein cholesterol concentration (LDL-C) (10.2 mg/dL [7.4% change]), ratio of LDL-C to high-density lipoprotein cholesterol concentration (HDL-C) (0.22 [8.3% change]), and ratio of total cholesterol concentration to HDL-C (0.24 [5.6% change]) (P & .001 for all) (to convert all cholesterol concentrations to millimoles per liter, multiply by 0.0259). Triglyceride levels were reduced by 20.6 mg/dL (10.2%) in subjects with blood triglyceride levels of at least 150 mg/dL (P & .05) but not in those with lower levels (to convert triglyceride level to millimoles per liter, multiply by 0.0113). The effects of nut consumption were dose related, and different types of nuts had similar effects on blood lipid levels. 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.
Conclusion Nut consumption improves blood lipid levels in a dose-related manner, particularly among subjects with higher LDL-C or with lower BMI.
