Omega-3: benefici contro ansia nell’uomo

Neuroscienze e nutrizione: Omega-3: benefici contro ansia nell’uomo

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.

La Vitamina D può ridurre la depressione nelle donne

Neuroscienze e nutrizione: La Vitamina D può ridurre la depressione nelle donne

Vitamin D intake from foods and supplements and depressive symptoms in a diverse population of older women.

English/Italiano

Bertone-Johnson ER, Powers SI, Spangler L, Brunner RL, Michael YL, Larson JC, Millen AE, Bueche MN, Salmoirago-Blotcher E, Liu S, Wassertheil-Smoller S, Ockene JK, Ockene I, Manson JE.

Am J Clin Nutr. 2011. Doi: 10.3945/ajcn.111.017384

ABSTRACT
Vitamin D may plausibly reduce the occurrence of depression in postmenopausal women; however, epidemiologic evidence is limited, and few prospective studies have been conducted. We conducted a cross-sectional and prospective analysis of vitamin D intake from foods and supplements and risk of depressive symptoms. Study participants were 81,189 members of the Women's Health Initiative (WHI) Observational Study who were aged 50-79 y at baseline. Vitamin D intake at baseline was measured by food-frequency and supplement-use questionnaires. Depressive symptoms at baseline and after 3 y were assessed by using the Burnam scale and current antidepressant medication use. After age, physical activity, and other factors were controlled for, women who reported a total intake of ≥800 IU vitamin D/d had a prevalence OR for depressive symptoms of 0.79 (95% CI: 0.71, 0.89; P-trend < 0.001) compared with women who reported a total intake of <100 IU vitamin D/d. In analyses limited to women without evidence of depression at baseline, an intake of ≥400 compared with <100 IU vitamin D/d from food sources was associated with 20% lower risk of depressive symptoms at year 3 (OR: 0.80; 95% CI: 0.67, 0.95; P-trend = 0.001). The results for supplemental vitamin D were less consistent, as were the results from secondary analyses that included as cases women who were currently using antidepressant medications. Overall, our findings support a potential inverse association of vitamin D, primarily from food sources, and depressive symptoms in postmenopausal women. Additional prospective studies and randomized trials are essential in establishing whether the improvement of vitamin D status holds promise for the prevention of depression, the treatment of depression, or both.

Commento
Un corpo esposto a luce solare produce vitamina D. Nei Paesi del Nord i livelli di esposizione sono così deboli durante i mesi invernali che il corpo non produce questa vitamina. Il che significa che i supplementi dietetici e gli alimenti fortificati sono l’unico modo per aumentare la sua assunzione. L'assunzione di una quantità superiore a 800 unità internazionali, tramite il consumo di alimenti che la contengono, è associata ad una riduzione del 21% dei sintomi depressivi nelle donne durante il periodo della menopausa. Questa osservazione è relativa ad uno studio condotto su 81.189 partecipanti di sesso femminile. L’assunzione della vitamina è stata misurata all'inizio dello studio mentre i sintomi della depressione sono stati testati utilizzando una scala ben consolidata.