Venkatraman J T, Feng X, Pendergast D
Department of Physical Therapy, Exercise and Nutrition Sciences, State University of New York at Buffalo, 14214, USA.
J Am Coll Nutr. 2001 Oct;20(5):529-36. doi: 10.1080/07315724.2001.10719062.
Exercise and the neuroendocrine and oxidative stress it elicits on immune function is modulated by dietary fat intake. The effects of increasing dietary fat on endurance exercise-induced alterations 80% of VO2max for 2 hours) in the plasma levels of cortisol and prostaglandin E2 (PGE2), interferon-gamma (IFN-gamma) and lipid peroxides were investigated. As higher levels of cortisol, PGE2 and lipid peroxides could be immunosuppressive, the effects of different levels of dietary fat on these measures in runners were determined.
Healthy trained runners (males and females) consumed serially 15% fat diet (of daily energy), 30% fat diet and 40% fat diets for four weeks each. In the last week of each diet period the subjects ran to exhaustion at 80% of their VO2max and blood was drawn pre- and post-run. Cortisol, IFN-gamma, PGE2 and lipid peroxides were determined using standard techniques.
Pre-exercise levels of plasma cortisol were elevated, IFN-gamma was unchanged and PGE2 and lipid peroxides decreased on the 40%F diet compared to 30%F and 15%F. Post-exercise levels of plasma cortisol (p < 0.004), PGE2 (p < 0.0057) and lipid peroxide levels increased (p < 0.0001) after endurance exercise on all diets. The rates of increase of plasma cortisol levels during exercise were similar on all three diets. Although absolute cortisol levels were higher in the high fat group, the rate of increase of plasma cortisol level during exercise was similar on each diet. The dietary fat levels did not affect IFN-gamma, however, PGE2 and lipid peroxides decreased with increasing fat at baseline at 40%F level (p < 0.01; 30%F vs. 40% F: p < 0.002; 15%F vs. 40%F: p < 0.007).
Data from the present study suggest that higher levels of fat in the diet, up to 40%, increase endurance running time without adverse effects on plasma cortisol, IFN-gamma, and lipid peroxide levels.
运动及其引发的对免疫功能的神经内分泌和氧化应激受膳食脂肪摄入量的调节。研究了增加膳食脂肪对耐力运动（最大摄氧量的80%，持续2小时）引起的血浆皮质醇、前列腺素E2（PGE2）、干扰素-γ（IFN-γ）和脂质过氧化物水平变化的影响。由于较高水平的皮质醇、PGE2和脂质过氧化物可能具有免疫抑制作用，因此确定了不同水平的膳食脂肪对跑步者这些指标的影响。
健康的受过训练的跑步者（男性和女性）依次食用15%脂肪饮食（占每日能量）、30%脂肪饮食和40%脂肪饮食，每种饮食持续四周。在每个饮食阶段的最后一周，受试者以最大摄氧量的80%跑步至 exhaustion，在跑步前后采集血液。使用标准技术测定皮质醇、IFN-γ、PGE2和脂质过氧化物。
与30%F和15%F饮食相比，40%F饮食时运动前血浆皮质醇水平升高，IFN-γ不变，PGE2和脂质过氧化物降低。所有饮食在耐力运动后血浆皮质醇（p < 0.004）、PGE2（p < 0.0057）和脂质过氧化物水平均升高（p < 0.0001）。三种饮食在运动期间血浆皮质醇水平的升高速率相似。虽然高脂肪组的绝对皮质醇水平较高，但每种饮食在运动期间血浆皮质醇水平的升高速率相似。膳食脂肪水平不影响IFN-γ，然而，在基线时，PGE2和脂质过氧化物随脂肪增加而降低，在40%F水平时（p < 0.01；30%F与40%F：p < 0.002；15%F与40%F：p < 0.007）。
本研究数据表明，饮食中高达40%的较高脂肪水平可增加耐力跑步时间，且对血浆皮质醇、IFN-γ和脂质过氧化物水平无不良影响。
