Men who pop too many vitamins in the hope of improving their health may in fact be raising their risk of the deadliest forms of prostate cancer, especially men with a family history of the disease.

Researchers at the National Cancer Institute found that men who exceeded the recommended dose — taking more than seven multivitamins a week — increased the risk of advanced cancer by about 30%.

"We didn't see any relationship with overall prostate cancer," said Dr. Michael Leitzmann, a National Cancer Institute investigator who worked on the study, published Wednesday in the Journal of the National Cancer Institute.

The association was strongest in men with a family history of prostate cancer and men who also took selenium, beta-carotene or zinc supplements.



Sleeping like a Martian baby

An experiment aimed at finding ways to help astronauts adapt to life on Mars could end up benefiting insomniacs on Earth.

In it, researchers found that two 45-minute exposures to bright light in the evening could help people adjust to a longer, Martian-style day.

"The results have powerful implications for the treatment of circadian rhythm sleep disorders, including shift work disorder and advanced sleep phase disorder," said Dr. Charles Czeisler, chief of the Division of Sleep Medicine at Brigham and Women's Hospital and Harvard medical school in Boston.

The study was published in Tuesday's issue of the Proceedings of the National Academy of Sciences.



Testosterone gel aids men with MS

A testosterone gel slowed brain deterioration and boosted thinking ability in men with multiple sclerosis, according to a small study showing a possible new way to treat the incurable disease.

Writing in the May issue of Archives of Neurology, UCLA researchers said the study was based on the fact that men develop the disease less frequently than women and the idea that the male sex hormone testosterone may be protective.

The men applied a testosterone gel to their shoulders daily for a year. Tests of cognitive — the ability to think, learn and judge — improved, and brain atrophy diminished to the level of normal aging, the study found.

The treated men also had increased muscle mass.

But the study involved only 10 men, and bigger studies are needed, the researchers cautioned.

From Times wire reports