People have been searching for the fountain of youth for a long time. Even the pharmaceutical industry, which has been the subject of many critiques for its track record in fighting illness with its gargantuan profits, understands that Americans want the country's health care system and researchers to fight cancer and heart disease and improve end-of-life care even as their own top personal goals are weight management, obesity and diet. It seems Americans at least intuitively understand that their personal health decisions somewhat influence the incidence of their more global health concerns.
That is not to say, of course, that a perfect diet and exercise regimen will necessarily shield anyone from cancer. Everything from environmental poisons and radiation to tobacco and too much sunlight can result in cancers. There are known genetic risk factors for heart disease as well.