Mori T A, Bao D Q, Burke V, Puddey I B, Beilin L J
Department of Medicine, University of Western Australia, and the West Australian Heart Research Institute, Perth, Australia.
Hypertension. 1999 Aug;34(2):253-60. doi: 10.1161/01.hyp.34.2.253.
Animal studies suggest that the 2 major omega3 fatty acids found in fish, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may have differential effects on blood pressure (BP) and heart rate (HR). The aim of this study was to determine whether there were significant differences in the effects of purified EPA or DHA on ambulatory BP and HR in humans. In a double-blind, placebo-controlled trial of parallel design, 59 overweight, mildly hyperlipidemic men were randomized to 4 g/d of purified EPA, DHA, or olive oil (placebo) capsules and continued their usual diets for 6 weeks. Fifty-six subjects completed the study. Only DHA reduced 24-hour and daytime (awake) ambulatory BP (P<0.05). Relative to the placebo group, 24-hour BP fell 5.8/3.3 (systolic/diastolic) mm Hg and daytime BP fell 3.5/2.0 mm Hg with DHA. DHA also significantly reduced 24-hour, daytime, and nighttime (asleep) ambulatory HRs (P=0. 001). Relative to the placebo group, DHA reduced 24-hour HR by 3. 5+/-0.8 bpm, daytime HR by 3.7+/-1.2 bpm, and nighttime HR by 2. 8+/-1.2. EPA had no significant effect on ambulatory BP or HR. Supplementation with EPA increased plasma phospholipid EPA from 1. 66+/-0.07% to 9.83+/-0.06% (P<0.0001) but did not change DHA levels. Purified DHA capsules increased plasma phospholipid DHA levels from 4.00+/-0.27% to 10.93+/-0.62% (P<0.0001) and led to a small, nonsignificant increase in EPA (1.52+/-0.12% to 2.26+/-0.16%). Purified DHA but not EPA reduced ambulatory BP and HR in mildly hyperlipidemic men. The results of this study suggest that DHA is the principal omega3 fatty acid in fish and fish oils that is responsible for their BP- and HR-lowering effects in humans. These results have important implications for human nutrition and the food industry.
动物研究表明，鱼类中发现的两种主要的ω-3脂肪酸，即二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），可能对血压（BP）和心率（HR）有不同的影响。本研究的目的是确定纯化的EPA或DHA对人体动态血压和心率的影响是否存在显著差异。在一项平行设计的双盲、安慰剂对照试验中，59名超重、轻度高脂血症男性被随机分为三组，分别每天服用4克纯化的EPA、DHA或橄榄油（安慰剂）胶囊，并继续他们的常规饮食6周。56名受试者完成了研究。只有DHA降低了24小时和白天（清醒）的动态血压（P<0.05）。与安慰剂组相比，服用DHA后24小时血压下降了5.8/3.3（收缩压/舒张压）毫米汞柱，白天血压下降了3.5/2.0毫米汞柱。DHA还显著降低了24小时、白天和夜间（睡眠）的动态心率（P=0.001）。与安慰剂组相比，DHA使24小时心率降低了3.5±0.8次/分钟，白天心率降低了3.7±1.2次/分钟，夜间心率降低了2.8±1.2次/分钟。EPA对动态血压或心率没有显著影响。补充EPA使血浆磷脂中的EPA从1.66±0.07%增加到9.83±0.06%（P<0.0001），但没有改变DHA水平。纯化的DHA胶囊使血浆磷脂中的DHA水平从4.00±0.27%增加到10.93±0.62%（P<0.0001），并使EPA略有非显著性增加（从1.52±0.12%增加到2.26±0.16%）。纯化的DHA而非EPA降低了轻度高脂血症男性的动态血压和心率。本研究结果表明，DHA是鱼类和鱼油中主要的ω-3脂肪酸，对人体具有降低血压和心率的作用。这些结果对人类营养和食品工业具有重要意义。
