Men's brains appear to deteriorate faster than women's, with males especially losing brain cells involved in language, reasoning and happiness, researchers reported.

A new study involving high-tech images of the brains of 69 men and women could indicate women are more likely than men to remain mentally sharp as they age, and perhaps explains why men might be more likely to become unhappy, researchers said Sunday."It may predict that men are more likely to get grouchy with age than women," said Ruben Gur of the University of Pennsylvania in Philadelphia, who helped conduct the study. "Some stereotypes have basis in reality."

The death of brain cells as people age has been well-known, primarily from examining and measuring the brains of people after they have died.

In the new study, Gur and his colleagues used a process known as magnetic resonance imaging to produce detailed images of the brains of 34 healthy men and 35 women ages 18 to 80.

The researchers found that while both men and women apparently tend to lose brain cells as they age, overall, the rate of brain cell death, called atrophy, was about three times higher in men than in women.

"We found some sex differences that have not been shown before," said Gur, director of the university's brain behavior laboratory and a professor of neuropsychology, psychiatry and neurology.

"We were able to show that the rate of cell loss is significantly faster in men than in women in aging," said Gur, who reported the findings in the Proceedings of the National Academy of Sciences.

Researchers are uncertain why male brains would deteriorate faster than female brains. But if hormones have anything to do with it, perhaps treatments could be developed to help reduce such deterioration, Gur said.

In addition, if the amount of brain loss found in the study is enough to influence ability, the findings indicate women should not have to retire earlier than men, which is the case in some countries, Gur said.

Men also tended to lose more cells from the more highly developed surface of the brain, which is thought to be involved in higher cognitive functions like reasoning, calculation, planning and conceptualization, than the center of the brain, which is believed to be involved in emotional regulation and survival, he said.

While women apparently tend to lose brain cells about equally on both sides of the brain, men in the study lost about twice as much brain on the left side as the right.

The left side of the brain is believed to be involved in language, speech, logical reasoning and analytical thought while the right side is associated with spatial abilities, facial recognition and other non-verbal reasoning.