Exercise might slow Alzheimer's

Alzheimer’s disease, with its inexorable loss of memory and self, understandably alarms most of us, especially since there are no cures for the condition and few promising drug treatments. But a cautiously encouraging new study in The Archives of Neurology suggests that, for some people, a daily walk or jog could lower the risk of developing Alzheimer’s disease or change its course.

For the experiment, researchers at Washington University in St. Louis examined 201 adults, ages 45-88, who were part of a continuing study at the university’s Knight Alzheimer’s Disease Research Center. Some of them had a family history of Alzheimer’s disease, but none, as the study began, had clinical symptoms. They performed well on tests of memory and thinking.

“They were, as far as we could determine, cognitively normal,” said Denise Head, an associate professor of psychology at Washington University, who led the study.

Head and her colleagues began by using positron emission tomography, an advanced scanning technique, to examine the volunteers’ brains for signs of amyloid plaques, the deposits that are a hallmark of Alzheimer’s and have been linked to its progression.

Next the researchers tested their volunteers for APOE-e4, a variant of a gene involved in cholesterol metabolism. Everyone carries the APOE gene, but those with the e4 variation are at 15 times the risk of developing Alzheimer’s disease, compared with those who do not carry the variant.

Finally, the scientists asked the volunteers to fill out detailed questionnaires about their exercise habits during the past 10 years.

Recently, many studies have looked at whether being active can lessen someone’s risk for Alzheimer’s disease, but the results have been inconsistent. Some studies, in both animals and people, have suggested that regular exercise has a protective effect, while others have found little discernible benefit.