Heavy smokers and heavy drinkers who do little exercise are five to six times more likely to develop cancer than healthy people who exercise every day, according to a recent study.

Susumu Sawada, of the health development center of Tokyo Gas Co., studied the relationship between smoking and drinking habits and the effects of exercise, as well as the connection between such habits and the risk of cancer.

He said the minimum risk of cancer for those who smoke more than 20 cigarettes a day is still 2.5 times higher than that for nonsmokers, regardless of how much exercise they do, while smokers who hardly exercise have a risk of cancer 5.1 times higher.

To prevent cancer, "It is important we stop smoking first and control our intake of alcohol," Sawada said. "Then we should exercise an hour every day."

As for drinking, people who drink more than 0.36 liter of alcohol a day and do not exercise have a 6.6 times higher risk of cancer than those who do not drink and who do exercise, according to Sawada. However, he added, a reasonable intake of alcohol does not affect the risk of cancer.

The study also showed that those who do not drink but also do not exercise have a 4.6 times greater risk of getting cancer than other nondrinkers who exercise every day. Sawada explained that the risk of cancer may be related to stress and physical characteristics.

The study was conducted on 9,039 Tokyo Gas employees over 16 years. The results of the study will be announced at the annual meeting of the Japanese Cancer Association, which started Wednesday in Yokohama.