Physical exercise to prevent multifactorial diseases: A warning written in our genes?

The human genome has about forty thousand genes and has been subject to strong selective pressure in various periods and different geographical areas. Various evidence sustains the hypothesis that the widespread nature of multifactor diseases is partly due to modified life-styles (reduced physical activity, over-eating) and partly to genetic inheritance selected over thousands of years for life-styles that persisted almost up to the start of the twentieth century. Physical activity could therefore be a natural remedy for recovering part of the imbalance caused by modern life-styles in bodies "born to run" and fed parsimoniously. In order to prescribe it as a cure, more research is necessary into the effects of physical activity on the body at molecular level and into individual predispositions to be used in targeted prevention programmes.