【原】以不饱和脂肪取代饱和脂肪可获他汀类降胆固醇效果

　　心血管疾病是全球首要死亡原因，每年所致死亡人数约1730万。减少心血管疾病的预防疗法即使比例很小，也可大大减少全国和全球发生心血管疾病的人数及其医疗成本。

　　2017年6月15日，美国心脏协会《循环》在线发表协会官方报告，推荐以多和单不饱和植物油取代饱和脂肪，有助于降低胆固醇、预防心血管疾病。

　　支持限制饱和脂肪的证据经常在科学文献和大众媒体中受到质疑。该报告回顾了现有证据，并解释了美国心脏协会（AHA）长期以来限制高饱和脂肪食物建议背后的科学框架。

　　第一作者、哈佛大学陈曾熙公共卫生学院心血管疾病教授弗兰克·萨克斯表示：希望能够直观地记录科学研究为何绝对支持限制饮食饱和脂肪预防心血管疾病，饱和脂肪会增加低密度脂蛋白胆固醇，这是导致动脉阻塞斑块和心血管疾病的主要原因。

　　饱和脂肪存在于肉类、全脂乳制品、热带植物油（例如椰子油、棕榈油）等。不饱和脂肪包括：玉米油、大豆油、花生油等多不饱和脂肪，橄榄油、菜籽油、红花油、牛油果油等单不饱和脂肪。

　　该报告要点如下：

• 降低饮食饱和脂肪摄入量并以多不饱和植物油代替的随机对照研究将心血管疾病减少约30%，与他汀类药物降低胆固醇的效果相似。

• 许多人群前瞻观察研究表明，饱和脂肪摄入量较低、多和单不饱和脂肪摄入量较高，与心血管疾病、其他主要原因、全部原因所致死亡率较低有相关性。

• 相比之下，以大多数精制碳水化合物和糖取代饱和脂肪，并不降低心血管疾病比例，并未降低临床研究中的心血管疾病。

• 以不饱和脂肪取代饱和脂肪，可降低引起动脉粥样硬化的低密度脂蛋白胆固醇，为人群和临床研究的心血管疾病发生率降低提供了生物学证据。

• 考虑到全部科学证据满足严格因果关系，故强烈建议降低饱和脂肪摄入量并以不饱和（尤其多不饱和）脂肪取代，可以降低心血管疾病发生率。

• 不建议孤立地将饱和脂肪转变为不饱和脂肪，而应结合整体的健康饮食模式，例如高血压饮食或地中海饮食，正如2013年美国心脏协会（AHA）和美国心脏病学会（ACC）生活方式指南、2015～2020年美国人饮食指南所强调的。

• 高血压饮食：1997年开展的饮食方法防止高血压（Dietary Approaches to Stop Hypertension，DASH）发现，如果摄入足够的谷物、蔬菜、水果、低脂或脱脂奶，以维持足够的钾、镁、钙等离子的摄入量，并尽量减少饮食脂肪（尤其是富含饱和脂肪的动物油），限制食盐摄入量，可以有效降低血压。因此，现在常以DASH饮食作为预防及控制高血压的饮食模式。

• 地中海饮食：泛指希腊、西班牙、法国、意大利南部等处于地中海沿岸的南欧各国以蔬菜水果、鱼类、五谷杂粮、豆类、橄榄油为主的饮食风格，研究发现地中海饮食可以减少心脏病风险，还可以保护大脑免受血管损伤，降低卒中和记忆力减退的风险。现在也用地中海式饮食代指有利于健康、简单、清淡以及富含营养的饮食。

小调查

Circulation. 2017 Jun 15. [Epub ahead of print]

Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association.

Sacks FM, Lichtenstein AH, Wu JHY, Appel LJ, Creager MA, Kris-Etherton PM, Miller M, Rimm EB, Rudel LL, Robinson JG, Stone NJ, Van Horn LV; American Heart Association.

Cardiovascular disease (CVD) is the leading global cause of death, accounting for 17.3 million deaths per year. Preventive treatment that reduces CVD by even a small percentage can substantially reduce, nationally and globally, the number of people who develop CVD and the costs of caring for them. This American Heart Association presidential advisory on dietary fats and CVD reviews and discusses the scientific evidence, including the most recent studies, on the effects of dietary saturated fat intake and its replacement by other types of fats and carbohydrates on CVD. In summary, randomized controlled trials that lowered intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil reduced CVD by ≈30%, similar to the reduction achieved by statin treatment. Prospective observational studies in many populations showed that lower intake of saturated fat coupled with higher intake of polyunsaturated and monounsaturated fat is associated with lower rates of CVD and of other major causes of death and all-cause mortality. In contrast, replacement of saturated fat with mostly refined carbohydrates and sugars is not associated with lower rates of CVD and did not reduce CVD in clinical trials. Replacement of saturated with unsaturated fats lowers low-density lipoprotein cholesterol, a cause of atherosclerosis, linking biological evidence with incidence of CVD in populations and in clinical trials. Taking into consideration the totality of the scientific evidence, satisfying rigorous criteria for causality, we conclude strongly that lowering intake of saturated fat and replacing it with unsaturated fats, especially polyunsaturated fats, will lower the incidence of CVD. This recommended shift from saturated to unsaturated fats should occur simultaneously in an overall healthful dietary pattern such as DASH (Dietary Approaches to Stop Hypertension) or the Mediterranean diet as emphasized by the 2013 American Heart Association/American College of Cardiology lifestyle guidelines and the 2015 to 2020 Dietary Guidelines for Americans.

KEYWORDS: AHA Scientific Statements; blood cholesterol; cardiovascular diseases, atherosclerosis; cholesterol, LDL; dietary fats; fatty acids, saturated; fatty acids, unsaturated

PMID: 28620111

PII: CIR.0000000000000510

DOI: 10.1161/CIR.0000000000000510