Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Salivary cortisol and mood in older adults, mediating effects of zinc supplementation

Cortisol effects mood and behaviour as it alters brain cells and some neurotransmitters. Negative mood has been associated with increased cortisol levels (Gold et al 1986), positive mood is associated with lowered cortisol levels (Rudolph and McAuley, 1995). The latter finding is less conclusive and more research is needed (Hubert and de Jong-Meyer, 1990). Zinc (Zn) supplementation may enhance positive mood (Fabris and Macchegiani, 1995) by its effect on tryptophan, which increases levels of serotonin leading to a reduction in cortisol levels (Hambridge and Mills, 1989) and an inhibitory effect on negative affect. Little research has been carried out looking at this in older adults. This study aimed at investigating the effects of Zn supplementation on cortisol levels and mood in healthy older adults. This is a randomised placebo controlled double blind intervention study investigating supplementation of either 15 or 30 mg Zn/day or placebo for six months on mood and cortisol levels.

A Northern Ireland sample of 43 older adults, aged 55-70 years were recruited. Baseline and 6 month follow up measures of salivary cortisol, measured using an enzyme immunoassay kit, were obtained twice a day for 7 consecutive days in conjunction with measures of positive and negative affect measured using the PANAS scale (Watson et al, 1988). Evening cortisol was negatively correlated to serum Zn and positive mood. Perceived stress was correlated to negative mood. Zinc supplementation did not effect cortisol levels. Cortisol levels were related to positive mood but Zn does not appear to mediate cortisol levels in healthy adults.

Reported by

Univ. Ulster
BT52 1SA Coleraine
United Kingdom