A British professor said one lifestyle change -- smoking cessation -- resulted in cutting in half the number of men dying in their 60s from heart disease. Sarah Harper, a professor of gerontology at the University of Oxford, said 11,000 men in their early 60s in Britain died each year in the 1980s from heart disease, but that number had been cut in half by 2000. Cancer deaths of males in the age group dropped by one-third and stroke deaths by two-thirds, Harper said. \"In 1971, half the U.K. male population was dead by their mid-70s; now nearly half are still alive in their mid-80s,\" Harper wrote in The Guardian. \"Up to two-thirds of the increase in male life expectancy can be attributed to the simple decision to quit smoking.\" Harper said there is growing evidence of the difference public health initiatives can make, even in today\'s high-tech, scientifically orientated society. Japan\'s proportion of people 65 and older increased from 6 percent to 23 percent in the last 50 years, while its healthcare expenditure -- a system that incorporates a large amount of social care and healthy lifestyles -- rose from 3 percent to 8 percent of its gross domestic product. In the United States, the percentage of seniors age 65 and older increased from 9 percent to 13 percent in the same time period, while U.S. healthcare expenditures increased from 5 percent to 17 percent of GDP, Harper said.