The 20th century rise in life expectancy is one of the great successes of public health, but has contributed importantly to the aging of western populations. Aging poses great challenges to the modern welfare state, not only by threatening the sustainability of pension systems but also by inducing a greater demand for social services, including health care. There is an urgent need for developing strategies which can help to alleviate the societal consequences of the aging of populations. Unfortunately, the ill-health which tends to accompany aging is often seen as an independent variable only, leading to higher rates of morbidity, work disability, and demand for health and social care services. There is good evidence to suggest that many manifestations of ill-health at advanced ages are amenable to intervention, e.g. prevention by lifestyle improvement or early detection, treatment by drugs or surgery, and functional rehabilitation by training and devices. The health care system should therefore not only be seen as part of the problem, but should be used to become part of the solution.