Nobody likes being stressed out, but could small amounts of stress actually be good for us? As Nature reports, new research suggests mice placed in a stressful environment warded off cancer more successfully than the control mice, which lived in smaller groups with fewer stimuli:
Researchers from the United States and New Zealand injected mice with melanoma cells — the deadliest form of skin cancer. After six weeks, mice raised in an enriched environment — extra-large cages housing 20 individuals with running wheels and other toys — had tumours that were almost 80% smaller than those in mice raised in standard housing — five animals to a cage with no additional stimulation. Whereas all the normally housed mice developed tumours, 17% of the mice from the enriched environment developed no tumours at all. Tests in mice with colon cancer showed the same effect.
And no, it's not just about exercise. Nature says giving the control mice running wheels didn't help reduce tumor growth. The full article has more details, but reportedly, the "enriched" mice had slightly more stress hormones and "markedly reduced levels of the hormone leptin, known to regulate appetite."