Exercise Saves Aging Brains

Exercise Saves Aging Brains....If this is not an incentive, I don't know what is!

Everyone knows exercise keeps bodies young, and now a new study confirms it keeps brains young, too. The study, carried out with mice, demonstrated that exercise reverses age-related decline in the creation of neural stem cells by restoring an essential brain chemical.

The focus of the study, which was performed by the National Cheng Kung University Medical College in Taiwan, was the hippocampus. Mammals, including both humans and mice, have a hippocampus on each side of the brain. When fewer new stem cells are produced in the hippocampus, which plays a major role in short term memory and spatial navigation, the result is an impairment of memory functions and of the capacity to learn. In Alzheimer’s disease, the hippocampus is one of the first areas of the brain to suffer damage.

The researchers knew from prior studies with mice that the production of stem cells in the hippocampus declined dramatically in middleaged mice, and also that exercise seemed to slow the decline. The new study aimed to trace the progression of the decline and to attempt to find out what causes it.

The study used mice that had been trained to exercise on a treadmill for an hour a day. Mice varying in age from young (aged 3 months) to old (24 months) were tested, with special attention given to mice aged 13 months, which for them is middleaged.

The study soon focused on a brain chemical known as “brain-derived neurotrophic factor” or BDNF. This chemical promotes “neurogenesis,” or the growth of new neurons, and supports the survival of existing ones.

As the researchers expected, the study showed that in the normal course of events, neurogenesis fell sharply in middleaged mice, with these mice having only about five percent of the number of neural stem cells of young mice.

Importantly, the researchers discovered that exercise slows down the loss of new nerve cells in the middleaged group while actually improving neural stem cell production by 200 percent over middleaged mice that did not exercise. Further, new nerve cell survival was up by 170 percent over the non-exercising group. Exercise also benefited young mice, producing an even stronger effect than in the older mice.

The researchers concluded that at least in mice, exercise—by stimulating the production of BDNF—promotes the development and survival of new brain cells.