Delarue J, Matzinger O, Binnert C, Schneiter P, Chioléro R, Tappy L
Laboratoire régional de nutrition humaine, Hôpital de la Cavale Blanche, Brest, France.
Diabetes Metab. 2003 Jun;29(3):289-95. doi: 10.1016/s1262-3636(07)70039-3.
A diet rich in n-3 fatty acids (fish oils) is associated with reduced risks of cardiovascular and metabolic diseases, but the mechanisms remain incompletely understood. Sympathoadrenal activation is postulated to be involved in the pathogenesis of these diseases, and may be inhibited by n-3 fatty acids. We therefore evaluated the effects of a diet supplemented with n-3 fatty acids on the stimulation of the sympathetic nervous system and of stress hormones elicited by a mental stress.
Seven human volunteers were studied on two occasions, before and after 3 weeks of supplementation with 7.2 g/day fish oil. On each occasion, the concentrations of plasma cortisol, and catecholamines, energy expenditure (indirect calorimetry), and adipose tissue lipolysis (plasma non esterified fatty acid concentrations) were monitored in basal conditions followed by a 30 min mental stress (mental arithmetics and Stroop's test) and a 30 min recovery period.
In control conditions, mental stress significantly increased heart rate, mean blood pressure, and energy expenditure. It increased plasma epinephrine from 60.9 +/- 6.2 to 89.3 +/- 16.1 pg/ml (p<0.05), plasma cortisol from 291 +/- 32 to 372 +/- 37 micromol/l (p<0.05) and plasma non esterified fatty acids from 409 +/- 113 to 544 +/- 89 micromol/l (p<0.05). After 3 weeks of a diet supplemented with n-3 fatty acids, the stimulation by mental stress of plasma epinephrine, cortisol, energy expenditure, and plasma non esterified fatty acids concentrations, were all significantly blunted.
Supplementation with n-3 fatty acids inhibits the adrenal activation elicited by a mental stress, presumably through effects exerted at the level of the central nervous system.
富含n-3脂肪酸（鱼油）的饮食与心血管疾病和代谢性疾病风险降低相关，但其机制仍未完全明确。交感肾上腺激活被认为参与了这些疾病的发病机制，且可能受到n-3脂肪酸的抑制。因此，我们评估了补充n-3脂肪酸的饮食对精神应激引起的交感神经系统刺激和应激激素的影响。
对7名人类志愿者进行了两次研究，分别在补充7.2克/天鱼油3周之前和之后。每次研究时，在基础状态下监测血浆皮质醇、儿茶酚胺浓度、能量消耗（间接测热法）和脂肪组织脂解（血浆非酯化脂肪酸浓度），随后进行30分钟的精神应激（心算和斯特鲁普测试）以及30分钟的恢复期。
在对照条件下，精神应激显著增加心率、平均血压和能量消耗。它使血浆肾上腺素从60.9±6.2皮克/毫升增加到89.3±16.1皮克/毫升（p<0.05），血浆皮质醇从291±32微摩尔/升增加到372±37微摩尔/升（p<0.05），血浆非酯化脂肪酸从409±113微摩尔/升增加到544±89微摩尔/升（p<0.05）。在补充n-3脂肪酸饮食3周后，精神应激对血浆肾上腺素、皮质醇、能量消耗和血浆非酯化脂肪酸浓度的刺激均显著减弱。
补充n-3脂肪酸可抑制精神应激引起的肾上腺激活，可能是通过在中枢神经系统水平发挥作用。
