Too much exercise would lead to Alzheimer's
Posted: January 29, 2011 3:41 AM PST
Exercise protects against dementia and Alzheimer's disease. But forcing the dose on the treadmill may have the opposite effect.
Or so argues that a psychologist Toronto, Mary Tierney, of Sunnybrook Hospital. She said that intense exercise lowers estrogen levels, which has a negative effect on cognitive performance.
Ms. Tierney has raised this possibility after seeing a study showing that more women are exercising, the lower their risk of breast cancer is high. The reason was the decline in estrogen levels - for this reason that hormone therapy at menopause increases the risk of cancer.
In an interview with WebMD site at a conference on Alzheimer's in Vienna in 2009, the Ontario researcher said she immediately made the connection with Alzheimer's disease. "People often say they can not have too much of a good thing," she said. In this case, it would appear so. "The results announced in Vienna just been published in the Journal of Alzheimer's Disease.
Ms. Tierney was particularly well placed to address this issue. When it unveiled the results of her research she has published a study showing that moderate exercise such as walking, reduces the risk of Alzheimer's.
To test his thesis, she studied the records of 90 women in their fifties who were followed for 15 years after the initial assessment. Those who did moderate exercise were less likely to suffer from Alzheimer's disease than those who were not at all, but also less than those who were heavy exercise. In the category of intense exercise, Ms. Tierney was attended aerobics, swimming lengths, running, jogging, basketball, mountain biking and racquetball. Walking, golf, volleyball, cycling on level ground, tennis and softball are considered moderate exercise.
How intense exercise and lack of estrogen they damage the memory? Research on rats show that the hormone enters the brain and helps the functioning of the hippocampus, which plays an important role in memory, Ms. Tierney said in his interview with WebMD.
Toronto researcher now wants to gather a larger sample of women to check the validity of the results and expand the type of cognitive tests. In her study, she served eight verbal memory tests.