The Food and Drug Administration said yesterday it was delaying the drafting of a new regulation banning saccharin probably until next fall because of a new Canadian study concluding that human males using artificial sweeteners face an increased risk of bladder cancer.

At the same time, another study, similar in form to the Canadian study, has reportedly concluded that "no association [of bladder cancer] with artificial sweeteners is found." The second study, made by the American Health Foundation, is to be published in Cancer, the journal of the American Cancer Society.

The American Health Foundation study was made by Ernst Winder, a leading authority on cancer causation, under the sponsorship of the National Cancer Institute and the American Cancer Society.

Like the Canadian study, Winder's research found that smoking substantially increased the risk of bladder cancer. Winder's study concluded that 50 per cent of the bladder cancer cases in males and 33 per cent in females could be accounted for by cigarette smoking and that reduction or cessation of smoking lowered the risk.

Winder's study also found a weak, but statistically insignificant, association with coffee-drinking and bladder cancer and use of non-nutritive artificial sweeteners in either males or females.

Experts noted yesterday that it is not unusual for different epidemiological studies to reach opposite conclusions when examining the same problem.

The Canadian study, the first ever to find an increased risk for humans from using artificial sweeteners, was made by the National Cancer Institute of Canada and four Canadian universities.

The FDA had proposed to ban saccharin from all food, beverages, ingested cosmetics and drugs allowing ent cosmetics and drugs allowing it to be sold only as a single ingredient drug in powder, tablet and liquid form with a cancer warning on the label. provided that manufacturers could demonstrate that saccharin was medically useful.The FDA moved to ban saccharin last March after another Canadian study indicated an association between saccharin and bladder cancer in animals.

Both the Canadian study of humans and Winder's research involved retrospective studies -- working back from a group that had bladder cancer to another with similar characteristics comprising individuals without bladder cancer. The Canadian study involved 480 males and 152 females in each group. The part of Winder's study involving the use of artificial sweeteners had 132 males and 31 females in each group.