As the number of patients with Alzheimer’s disease is going to quadruple worldwide by 2050 reaching approximately 106 million cases, the researchers try to find answers on how to treat or to ease symptoms of this devastating disease.

Therefore, pharmaceutical companies have tried to develop drugs to fight Alzheimer’s, which causes a progressive loss of memory and mental faculties, but none of them appears to improve the condition. There are currently five drugs approved to treat Alzheimer’s, but they only mask symptoms for 6 to 12 months at most, according to the Alzheimer’s Association, an advocacy group based in Chicago.

It has long been know that physical exercise on regular basis is good for the body, improving health. Now, two new studies presented Sunday at the 2008 International Conference on Alzheimer’s Disease in Chicago, reveal that physical exercise is also good for the mind of people with early Alzheimer’s.

According to one of the studies, magnetic resonance imaging (MRI) showed that physical exercise has a positive effect on hippocampus, an area of the brain important for both memory and balance. In Alzheimer’s, the hippocampus is one of the first regions of the brain that has to suffer damage.

“This is the first study to get an inside look into specifically where these changes occur in the brain – we’re able to locate the changes associated with fitness to the actual memory region, the hippocampus, which is a key area for Alzheimer’s-related atrophy. This suggests that maintaining cardiorespiratory fitness may positively modify Alzheimer’s-related brain atrophy,” Robyn A. Honea, PhD, of the University of Kansas Medical Center, in Kansas City and a lead investigator on the study, said.

The Alzheimer’s patients who were non-carriers of the APOE4 gene benefited the most from exercising. APOE4 gene is known to increase the risk of developing Alzheimer’s.

The theory is bolstered by a study published July 15 in the journal Neurology, which involved a group of 121 people age 60 and older, including 57 who had early Alzheimer’s. The participants were put on treadmills to measure their peak oxygen consumption, which is the standard used to measure cardiorespiratory fitness.

The study found that people with Alzheimer’s who had low levels of fitness had four times more brain shrinkage than those with Alzheimer’s who had high levels of fitness. However, lead author Jeffrey Burns, an associate professor of neurology at the University of Kansas School of Medicine noted that the study looked at fitness levels but not exercise activities. What remains to be seen is whether exercise itself can help prevent brain atrophy in people who are at risk for developing Alzheimer’s. “The cause and effect has yet to be established, but evidence is building,” Burns said.

Another separate study presented at the same conference revealed that a 12-month home-based exercise program reduced falls and improved balance in patients with dementia. People with dementia usually fall up to three times more than those who have no cognitive impairment, according to researchers from Western Medicine, a consultant physician service provider for Hollywood Hospital in Nedlands, Western Australia, which conducted the study.

“Falls have a negative impact on a person’s quality of life, often resulting in nursing home placement, increased mortality and significant costs to the community. Targeting this high risk may be a relatively cost effective way of having a significant impact on the overall rate of falling in the elderly,” Megan J. Wraith, a speech pathologist at Western Medicine and a researcher on the study said.

The two studies were funded by the National Institute on Aging and National Institute on Neurological Disorders and Stroke, and the Sir Charles Gairdner Research Foundation and Hollywood Private Hospital Research Foundation.