The incidence of many diseases, including heart attacks and multiple sclerosis, peaks in winter time. Now it looks like this could be an unfortunate throw-back to our prehistoric origins. Cambridge University scientist John Todd has found that the immune system goes through annual cycles of activity, with peak levels of inflammation coinciding with winter time. Historically, this would have protected our ancestors, but in the more luxurious modern era we inhabit, it's boosting our disease risk, as he explained to Georgia Mills... Like this podcast? Please help us by supporting the Naked Scientists