Omega-3 supplementation lowers inflammation and anxiety in medical students: A randomized controlled trial.
English/Italiano
American Journal of Clinical Nutrition. 2010;91: 757-770
Kiecolt-Glaser JK., Belury MA, Andridge R, Malarkey WB, Glaser R
ABSTRACT
Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) production and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis.
Commento
La maggior parte degli studi scientifici inerenti gli omega-3 si sono concentrati sui benefici cardiovascolari, ma un numero crescente di studi riportano i potenziali effetti a livello cognitivo e comportamentale. Una dose giornaliera di 2.5 g di omega-3 può ridurre i sintomi ansiosi di circa il 20% in individui senza una diagnosi di disturbo d'ansia. Nello studio sono stati reclutati 68 studenti di medicina i quali hanno assunto capsule contenenti oli ricchi di omega-3 (contenenti 2085 mg di EPA e 348 mg DHA): si è osservata una riduzione del 14% dei livelli di produzione di interleuchina pro-infiammatoria 6 (IL-6), nonché una riduzione del 20% dei sintomi ansiosi. Gli omega-3 promuovono la secrezione di CRH, l’ormone responsabile del rilascio di corticotropina e quindi correlato alla risposta allo stress: CRH stimola l'amigdala, una regione del cervello che controlla stati di paura ed ansia.
English/Italiano
American Journal of Clinical Nutrition. 2010;91: 757-770
Kiecolt-Glaser JK., Belury MA, Andridge R, Malarkey WB, Glaser R
ABSTRACT
Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) production and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis.
Commento
La maggior parte degli studi scientifici inerenti gli omega-3 si sono concentrati sui benefici cardiovascolari, ma un numero crescente di studi riportano i potenziali effetti a livello cognitivo e comportamentale. Una dose giornaliera di 2.5 g di omega-3 può ridurre i sintomi ansiosi di circa il 20% in individui senza una diagnosi di disturbo d'ansia. Nello studio sono stati reclutati 68 studenti di medicina i quali hanno assunto capsule contenenti oli ricchi di omega-3 (contenenti 2085 mg di EPA e 348 mg DHA): si è osservata una riduzione del 14% dei livelli di produzione di interleuchina pro-infiammatoria 6 (IL-6), nonché una riduzione del 20% dei sintomi ansiosi. Gli omega-3 promuovono la secrezione di CRH, l’ormone responsabile del rilascio di corticotropina e quindi correlato alla risposta allo stress: CRH stimola l'amigdala, una regione del cervello che controlla stati di paura ed ansia.
