Kelley D S, Taylor P C, Nelson G J, Mackey B E
USDA, ARS, Western Human Nutrition Research Center, Presidio of San Francisco, California 94129, USA.
Lipids. 1998 Jun;33(6):559-66. doi: 10.1007/s11745-998-0240-8.
The purpose of this study was to examine the effect of dietary docosahexaenoic acid (DHA), in the absence of eicosapentaenoic acid, on human immune response (IR). A 120-d study with 11 healthy men was conducted at the Metabolic Research Unit of the Western Human Nutrition Research Center. Four subjects (control group) were fed the stabilization or basal diet (15, 30, and 55% energy from protein, fat, and carbohydrate, respectively) throughout the study; the remaining seven subjects (DHA group) were fed the basal diet for the first 30 d, followed by 6 g DHA/d for the next 90 d. DHA replaced an equivalent amount of linoleic acid; the two diets were comparable in their total fat and all other nutrients. Both diets were supplemented with 20 mg d-alpha-tocopherol acetate per day. Indices of IR were examined on study day 22, 30, 78, 85, 106, and 113. Addition of DHA at moderately high levels did not alter the proliferation of peripheral blood mononuclear cells cultured with phytohemagglutinin or concanavalin A, or the delayed hypersensitivity skin response. Also, additional DHA did not alter the number of T cells producing interleukin 2 (IL2), the ratio between the helper/suppressor T cells in circulation, or the serum concentrations of immunoglobulin G, C3, and interleukin 2 receptor (IL2R). DHA supplementation, however, caused a significant (P = 0.0001) decrease in the number of circulating white blood cells which was mainly due to a decrease in the number of circulating granulocytes. The number of lymphocytes in peripheral circulation was not affected by Dietary DHA enrichment, but the percentage of lymphocytes in white blood cells increased because of a reduction in granulocyte numbers. None of these indices was changed in the control group. Our results show that when total fat intake is low and held constant, DHA consumption does not inhibit many of the lymphocyte functions which have been reported to be inhibited by fish oil consumption.
本研究的目的是在不含二十碳五烯酸的情况下，检测膳食二十二碳六烯酸（DHA）对人体免疫反应（IR）的影响。在西部人类营养研究中心的代谢研究室对11名健康男性进行了一项为期120天的研究。4名受试者（对照组）在整个研究过程中食用稳定或基础饮食（分别来自蛋白质、脂肪和碳水化合物的能量为15%、30%和55%）；其余7名受试者（DHA组）在最初30天食用基础饮食，随后90天每天食用6克DHA。DHA替代了等量的亚油酸；两种饮食的总脂肪和所有其他营养素含量相当。两种饮食均每天补充20毫克d-α-生育酚醋酸酯。在研究的第22、30、78、85、106和113天检测IR指标。适度高水平添加DHA并未改变用植物血凝素或伴刀豆球蛋白A培养的外周血单个核细胞的增殖，或迟发型超敏皮肤反应。此外，额外的DHA并未改变产生白细胞介素2（IL2）的T细胞数量、循环中辅助/抑制性T细胞的比例，或免疫球蛋白G、C3和白细胞介素2受体（IL2R）的血清浓度。然而，补充DHA导致循环白细胞数量显著减少（P = 0.0001），这主要是由于循环粒细胞数量减少所致。外周循环中的淋巴细胞数量不受膳食DHA富集的影响，但由于粒细胞数量减少，白细胞中淋巴细胞的百分比增加。对照组的这些指标均未改变。我们的结果表明，当总脂肪摄入量较低且保持恒定时，摄入DHA不会抑制许多据报道会被鱼油摄入抑制的淋巴细胞功能。
