Physical exercise appears to slow down the development of Alzheimer's disease. New research data, published in the journal Neurology, shows that seniors who were less fit had four times more signs of brain shrinkage than those who were fit.

The results are also consistent with other studies which found that exercising cuts the risk of dementia. The 121 seniors tested were put on treadmills to measure their peak oxygen consumption, which is the standard used to measure cardiorespiratory fitness.

The problem is that there might be a link between low cardiorespiratory fitness and Alzheimer's, in the form of an underlying condition which favors both. This means that higher brain volumes in those physically fit may not be directly related to exercising. There is also the possibility that Alzheimer's itself causes lower cardiorespiratory fitness.

Alzheimer’s causes a progressive loss of memory and mental faculties, which can be devastating for the patients concerned and those around them. According to the World Health Organization, there are about 18 million people worldwide with Alzheimer’s disease. By 2025, that number is expected to reach 34 million, as existing drugs can ease symptoms but do not stop the disease.

Last month, Myriad Genetics, Inc. has announced its upcoming Alzheimer drug Flurizan (tarenflurbil) which the company alleges that it works in two different ways to stop the disease. Tarenflurbil is part of a class called gamma-secretase modulators (GSM), whose exact way of action was still unclear.

Also, in late June, a team led by Dr. Ganesh M. Shankar and Dr. Dennis J. Selkoe of Harvard Medical School has found that a particular form of beta-amyloid, extracted from brains of dead humans, causes Alzheimer's in rats. This partly solves a medical dilemma which surrounded the fact that although some people develop beta-amyloid plaques they do not have Alzheimer's symptoms. The new experiment points out the area where future research needs to focus, which might eventually lead to developing a cure or means to prevent Alzheimer's altogether.