Washington: Here's more evidence that regular exercise does all sorts of good - a new study has found that patients with mild Alzheimer's who exercised had larger brains than those who did not.

As part of the study, 121 people aged 60 and above underwent fitness tests using a treadmill as well as brain scans to measure the white and grey matter and total brain volume.

Of the group, 57 were in the early stages of Alzheimer's disease while the rest of the group did not have dementia.

"People with early Alzheimer's disease who were less physically fit had four times more brain shrinkage when compared to normal older adults... suggesting less brain shrinkage in those with higher fitness levels," said Jeffrey M. Burns of the University of Kansas and the study's author.

The results remained the same regardless of age, gender, severity of dementia, physical activity and frailty. There was no relationship between higher fitness levels and brain changes in the group of people without dementia.

"People with early Alzheimer's may be able to preserve their brain function for a longer period by exercising regularly and potentially reducing the amount of brain volume lost.

"Evidence shows decreasing brain volume is tied to poorer cognitive performance, so preserving more brain volume may translate into better cognitive performance," Burns said.

"This is one of the first studies to explore the relationship between cardio-respiratory fitness and Alzheimer's disease," said Burns.

Burns said people should be cautious when interpreting the study results because scientists only observed the standard measure of fitness at one point in time.

The findings of the study have been published in the latest issue of the journal Neurology. IANS