Moore Carmel S, Bryant Susan P, Mishra Gita D, Krebs Jeremy D, Browning Lucy M, Miller George J, Jebb Susan A
Medical Research Council Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK.
Nutrition. 2006 Oct;22(10):1012-24. doi: 10.1016/j.nut.2006.07.005.
Previous studies have demonstrated benefits of high-dose long-chain omega-3 polyunsaturated fatty acid (LC omega-3 PUFA) supplements on metabolic risk. Effects of increased dietary omega-3 PUFA, via oily fish and/or plant-derived omega-3 PUFAs, are less clear and may be modulated by the omega-6:omega-3 PUFA of the habitual diet. This study examined the effect on cardiovascular disease risk markers of reducing dietary omega-6:omega-3 PUFA by changes in linoleic acid:alpha-linolenic acid (LA:LNA) and/or increasing LC omega-3 PUFA. It tested whether decreases in LA:LNA modulate effects of LC omega-3 PUFA.
One hundred forty-two subjects, recruited to a 24-wk randomized study, were assigned to a control group or one of four interventions. Intervention groups received two portions of oily fish (4.5 g eicosapentaenoic acid + docosahexanoic acid) or white fish (0.7 g eicosapentaenoic acid + docosahexanoic acid) per week, and replaced habitual household fats with ones high in sunflower (high LA:LNA) or rapeseed (low LA:LNA) oil.
Modest dietary manipulations of omega-6 and omega-3 PUFAs resulted in significant group x time interactions for serum triacylglycerols (TAGs; P = 0.05); at 24 wk the control and two oily fish groups showed lower TAG than did the white fish/sunflower group (P = 0.05). Reductions in TAG, associated with increased oily fish intakes, were maximized when combined with lower dietary LA:LNA. There were no significant changes in several other cardiovascular disease risk markers.
Two portions of oily fish per week led to significant reductions in TAG relative to consumption of two portions of white fish per week. Changes in TAG were maximized when combined with lower LA:LNA.
既往研究已证明高剂量长链ω-3多不饱和脂肪酸（LC ω-3 PUFA）补充剂对代谢风险有益。通过油性鱼类和/或植物来源的ω-3多不饱和脂肪酸增加膳食中ω-3多不饱和脂肪酸的效果尚不清楚，且可能受习惯性饮食中ω-6:ω-3多不饱和脂肪酸的调节。本研究通过改变亚油酸:α-亚麻酸（LA:LNA）和/或增加LC ω-3多不饱和脂肪酸，探讨降低膳食中ω-6:ω-3多不饱和脂肪酸对心血管疾病风险标志物的影响。研究了LA:LNA的降低是否会调节LC ω-3多不饱和脂肪酸的作用。
142名受试者被招募参加一项为期24周的随机研究，被分配到对照组或四种干预措施之一。干预组每周食用两份油性鱼类（4.5克二十碳五烯酸+二十二碳六烯酸）或白鱼（0.7克二十碳五烯酸+二十二碳六烯酸），并用富含向日葵油（高LA:LNA）或菜籽油（低LA:LNA）的油脂替代习惯性家用油脂。
对ω-6和ω-3多不饱和脂肪酸进行适度的膳食调整后，血清三酰甘油（TAGs）出现显著的组×时间交互作用（P = 0.05）；在24周时，对照组和两个油性鱼类组的TAG低于白鱼/向日葵油组（P = 0.05）。当与较低的膳食LA:LNA相结合时，与油性鱼类摄入量增加相关的TAG降低幅度最大。其他几种心血管疾病风险标志物无显著变化。
每周食用两份油性鱼类相对于每周食用两份白鱼可使TAG显著降低。当与较低的LA:LNA相结合时，TAG的变化最大。
