New York: Men and women with early-stage Alzheimer’s disease who were more physically fit also had larger brains compared to those who failed to keep fit.

Alzheimer’s and Memory Program at the Univesity of Kansas School of Medicine, are at an early stage but scientists believe they indicate that physical fitness may slow shrinkage of the brain, one of the symptoms of Alzheimer’s Disease.

In older adults without dementia, staying in good physical shape may help offset the changes in the brain, such as cognitive decline, associated with normal aging.

But experts have not yet clearly defined whether or not physical activity has an effect on those with Alzheimer’s.

For this study, 57 people with early-stage Alzheimer’s and 64 people without dementia, all aged 60 and over, underwent standard fitness tests and MRI brain scans.

“We used an objective, gold-standard measure of fitness which hadn’t been assessed in Alzheimer’s patients yet, cardiorespiratory fitness, or VO2 peak, where we basically measure how much work someone is capable of doing,” Burns explained.

Participants walked on a treadmill while their oxygen consumption was measured. “At their peak, how much oxygen they’re consuming is a measure of how physically fit they are,” Burns said.

MRI scans measured brain atrophy.

The VO2 peak was slightly lower in people with Alzheimer’s compared to controls. And individuals with Alzheimer’s who were less physically fit had quadruple the amount of brain shrinkage compared to normal older adults.

The study pointed to three possible explanations for the relationship: cardiorespiratory fitness affects brain atrophy related to Alzheimer’s disease; the Alzheimer’s disease process affects fitness; or some other, as-yet-unknown factor underlies both Alzheimer’s-related brain atrophy and physical fitness.

“We’re designing a study where we try to establish the cause and effect,” Burns said. “Can we use exercise to enhance fitness in Alzheimer’s disease and, by doing that, will it affect disease progression?”

For more information on how to keep your brain in shape try the Alzheimier’s Association’s Maintain your Brain Programm