A recent study carried out in the U.S. showed that healty eating and exercise is benifical for older people.  People were less likely to have risk factors for cardiovascular disease, such as hypertension, diabetes, or high cholesterol levels. 

For an abstract of the reserch go to http://jama.ama-assn.org/

Also see this report in The Telegraph http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2007/12/05/scifit105.xml