Exercise May Fight Depression in Older Adults, Study Suggests

A study published in the American Journal of Physiology — Cell Physiology suggests exercise-induced muscle changes could help improve depression in older adults, reports Medical Xpress . The expression of transcription factors help regulate gene expression and the processing of the mood-enhancing chemical tryptophan. Tryptophan is similar to serotonin, whose concentration in the blood is low in people with depression. Tryptophan metabolism occurs almost completely through the kynurenine pathway, which branches out into either a path protective of brain tissue or into one that is damaging. The former path requires the KAT enzyme to function, and aerobic and resistance exercise promote KAT activity and tryptophan metabolism via the neuroprotective branch. For the study, a group of healthy men 65 or older, without history of depression, participated in a 12-week trial involving resistance exercise and high-intensity interval training on a stationary bicycle. Their gene and protein expression in the muscles before, during, and after the trial were measured. The researchers observed that the expression of transcription factors and KAT rose significantly during the trial, which was consistent with previous research performed in younger adults.