Kris-Etherton Penny M, Fleming Jennifer A
Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA
Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA.
Adv Nutr. 2015 May 15;6(3):326S-37S. doi: 10.3945/an.114.006981. Print 2015 May.
Recent dietary guidance for heart health recommends a reduction (by ∼50%) in saturated fatty acid (SFA) intake to reduce LDL cholesterol and to decrease risk of cardiovascular disease (CVD). The 2010 Dietary Guidelines for Americans recommends substituting unsaturated fat [both polyunsaturated and monounsaturated fatty acids (PUFAs and MUFAs, respectively)] for SFAs. There are many dietary options that can be implemented to replace SFAs, given the different sources of unsaturated fats in the food supply. Compelling evidence exists for the cardioprotective benefits of n-3 (ω-3) PUFAs, both marine- and plant-derived. In addition, the evidence of cardioprotective benefits of n-6 (ω-6) PUFAs is strong, whereas that for MUFAs is mixed, although there is emerging evidence of benefits. Quantitatively, lowering SFAs by 50% will require, in part, substituting food sources of n-6 and n-3 PUFAs and MUFAs for food sources of SFAs. The use of n-3 PUFAs as a replacement for SFAs will result in a shortfall in reaching the SFA goal because of the relatively low amounts that can be incorporated in the diet, even with very high n-3 PUFA substitution. SFAs also can be replaced with dietary carbohydrate and/or protein. Replacing SFAs with carbohydrate, specifically refined sources, however, has little impact on reducing CVD risk. There is evidence about the health benefits of dietary protein on CVD risk, which merits study. Dietary guidelines have advanced considerably with the "replacement of SFA with unsaturated fat message" instead of recommending decreasing SFAs alone. A key question that remains is what is the optimal mix of macronutrients to maximally reduce CVD risk.
近期关于心脏健康的饮食指南建议将饱和脂肪酸（SFA）摄入量减少约50%，以降低低密度脂蛋白胆固醇并降低心血管疾病（CVD）风险。《2010年美国膳食指南》建议用不饱和脂肪（多不饱和脂肪酸和单不饱和脂肪酸，分别为PUFA和MUFA）替代SFA。鉴于食物供应中不饱和脂肪的不同来源，有许多饮食选择可用于替代SFA。有令人信服的证据表明，海洋和植物来源的n-3（ω-3）PUFA具有心脏保护益处。此外，n-6（ω-6）PUFA具有心脏保护益处的证据确凿，而MUFA的相关证据则好坏参半，不过也有新出现的有益证据。从数量上看，将SFA降低50%部分需要用n-6和n-3 PUFA以及MUFA的食物来源替代SFA的食物来源。使用n-3 PUFA替代SFA会导致无法达到SFA目标，因为即使进行非常高比例的n-3 PUFA替代，其在饮食中可摄入的量相对较低。SFA也可用膳食碳水化合物和/或蛋白质替代。然而，用碳水化合物，特别是精制碳水化合物替代SFA对降低CVD风险几乎没有影响。有证据表明膳食蛋白质对CVD风险有益，值得研究。膳食指南随着“用不饱和脂肪替代SFA的信息”有了很大进展，而不是仅仅建议减少SFA。仍然存在的一个关键问题是，什么是能最大程度降低CVD风险的最佳宏量营养素组合。
