Washington: A new study has suggested that living in an environment rich with physical, mental and social stimulation – a setting that causes mild stress – might by itself curb cancer growth.
The animal study, led by researchers at The Ohio State University Comprehensive Cancer Center – Arthur G James Cancer Hospital and Richard J Solove Research Institute, also shows how this effect happens and that it might have therapeutic use.
The researchers discovered that an enriched environment activates a nervous-system pathway by which the brain talks to fat tissue.
That pathway, called the hypothalamic-sympathoneural-adipocyte (HSA) axis tells fat cells to stop releasing a hormone called leptin into the bloodstream.
Leptin normally helps restrain appetite, but this study discovered that it also accelerates cancer growth.
The enriched environment had the same cancer-curbing influence in models of melanoma and colon cancer.
"People tend to think that cancer survivors should avoid stress, but our data suggests that this is not completely true," says research leader Dr Matthew J During, professor of neuroscience, of neurological surgery and of molecular virology, immunology and medical genetics.
"The anti-cancer effect we observed in this study was not due simply to increased activity by the animals, but rather it was induced by social and physical challenges that are associated with the release of stress hormones from the adrenal gland.
"But the most dramatic hormonal change we observed was the drop in leptin from fat after richer housing conditions activated the HSA pathway. That pathway is also present in humans, where it is likely to be activated by a more complex and challenging life," he adds.
The study has been published in the July 9 issue of the journal Cell.