Tai chi, the martial art that has become popular as a gentle mind-body workout, may have another benefit: Helping to increase the size of the brain. And brain growth, scientists hope, could unlock a clue to staving off and even preventing dementia.
Chinese seniors who practiced tai chi three times a week increased their brain volumes and scores on tests of memory and thinking, said a study of 120 participants published in the Journal of Alzheimer's Disease.
Lead researcher James Mortimer, a University of South Florida professor of epidemiology and biostatistics, cautioned that the study is preliminary. Still, it's intriguing. He said, "In the tai chi group, we saw brain growth of one-half of 1 percent over eight months" measured through MRIs. How exactly that growth occurred -- and whether genetics or other factors might play into it -- is a topic for a new study, he said.
Studies have found that statins reduce the risk for recurring cardiac problems, but not the risk for death. Now an analysis suggests that the drugs may reduce mortality significantly only in men.
For the report, in Archives of Internal Medicine, researchers reviewed 11 randomized, double-blinded, placebo-controlled studies of statins that included 43,191 people, one-fifth of them women. For both sexes, statins were effective compared with placebos in preventing cardiovascular events and led to lower rates of coronary mortality and heart attacks.
But two of the five trials that reported on "all-cause mortality" showed a reduced risk for men, while none did for women. Overall, statins did not reduce stroke in women but were linked to a 16 percent lower risk for men.
The scientists said the disparity might be explained by such technical factors as less vigorous recruitment of women or a worse cardiovascular profile for those women, or by the undertreatment of women for other conditions that could contribute to disease.
"Our intention is not to have women stop using statins," said the lead author, Dr. Jose Gutierrez, a clinical instructor in neurology at Columbia. "For overall secondary prevention, statins work for women. But for two outcomes -- stroke and all-cause mortality -- they are not as beneficial."
Premature birth may increase the risk for serious mental illness in adolescence and young adulthood, a recent study reports.
Researchers reviewed birth and hospital admissions records of more than 1.3 million Swedes born from 1973 to 1985. They found that compared with those born at term, young adults born very premature -- at less than 32 weeks' gestation -- were more than twice as likely to be hospitalized for schizophrenia or delusional disorders, almost three times as likely for major depression, and more than seven times as likely for bipolar illness.
The lead author, Chiara Nosarti, a senior lecturer in neuroimaging at Kings College London, emphasized that while the increase in relative risk is substantial, the absolute increase in numbers of people with the illnesses is not.
"Despite these findings," she said, "the majority of people born preterm have no psychiatric problems, and the number of people hospitalized with psychiatric disease is very low."
Still, she added, "routine screening may help to detect early signs of illness."
The risk also increased for people born late preterm, or 32 to 36 weeks' gestation, but not as sharply. They were 60 percent more likely to be admitted for schizophrenia or delusional disorders, 34 percent more likely for depressive disorder, and about twice as likely to be hospitalized for bipolar illness.