Americans should increase the amount of selenium in their diets to help prevent cancer, a noted professor of nutrition said yesterday.

A diet supplemented with selenium, a trace element found in fish, fibers and grains, has been shown to inhibit the effect of carcinogens, John A. Milner, professor and head of the Department of Nutrition, told an audience of about 50 people.

"One out of four of us will get cancer sometime during our lifetime," Milner said, "and one out of ten of us will die."

The diet is clearly linked to cancer, he said, adding that 50 to 60 percent of cancers can be related to diet.

"Diet is a lifelong process that can have dramatic implications," Milner said.

Milner recommends doubling the daily selenium intake not only to inhibit cancer growth but also to improve overall health. Currently, Americans eat about 75 to 150 micrograms of selenium.

Milner emphasized that a selenium deficiency will not increase the risk of cancer, but a selenium supplement will inhibit the risk.

Milner's research involved using the carcinogen dimethylbenzanthracene to induce mammarian tumors in rats. Selenium supplemented diets were then given to the rats during the three different phases of cancer.

The rats that had been given selenium during the first phase of cancer, when the carcinogen alters the DNA gene, were found to have almost a 50 percent decrease in tumor growth than the control group. Selenium administered in later stages, although it stopped tumor growth, was not as effective in curing it, Milner said.

"Selenium can prohibit the binding of a carcinogen to the DNA," Milner said, therefore preventing the first stage.

It was shown in human mammary cells that selenium inhibits cancer growth in human as well as animal cells.

"Selenium clearly is not only effective in inhibiting cells of animal origin but of human origin as well," Milner said.

Despite reports as early as 1966 that selenium may have been an anti-carcinogen, clinical studies involving humans are just now becoming accepted because some people still believe selenium is harmful. In the 1930s and 1940s selenium was thought to be highly toxic and cancer causing itself, Milner said.

Milner said selenium should be combined with classic forms of cancer treatments such as chemotherapy and radiation therapy to form more effective treatments.

Amy Salem (graduate-veterinary science) said she found Milner's research very interesting.

"I think it is obvious that selenium will play a role in dealing with cancer in the future, but they are not sure how," she said. "It may be affecting some enzymes we don't know about yet."

While more research needs to be done, we are convinced that selenium is an effective factor in inhibiting cancer, Milner said.