Kansas City, KS — A new study shows that exercise may help slow brain shrinkage in people with early Alzheimer's disease. In the study, people with early Alzheimer's who were less physically fit had four times more brain shrinkage than normal older adults.

One of the authors of the study, published last month in the journal Neurology, is Jeffrey Burns, who directs the Alzheimer and Memory Program at the University of Kansas School of Medicine in Kansas City, KS. While brains shrink with normal aging, the rate is doubled in people with Alzheimer's disease, Burns says.

The study included 57 people over the age of 60 in the early stages of Alzheimer's. The participants' physical fitness was assessed by measuring peak oxygen demand while on a treadmill. Brain shrinkage was estimated by MRI scans.

The study also showed that participants who were more physically fit did not do significantly better on tests for mental performance. Burns says the study may have had too few patients to show an effect in the analysis. He adds that the work is only a starting point for exploring whether exercise and physical fitness can slow the progression of Alzheimer's and that the study cannot prove an effect because the participants were evaluated only once rather than repeatedly over time.

According to previous studies and the AARP, exercise can help the brain in a number of ways, including improving concentration and attention, reducing gray-matter loss, promoting neurogenesis, enhancing blood flow and strengthening synapses.