Fitness the key to our brains running well

WHAT is good for our hearts is also good for our brains.

Victorian research institutes are among those contributing to growing evidence that huff-and-puff exercise — while keeping our cholesterol in check and our arteries wide and supple — is equally important to the vascular system in the brain.

Florey Institute of Neuroscience and Mental Health clinical neuropsychologist Dr Jo Robertson said their studies showed one of the most important factors for brain health was cardiovascular exercise.

“The cardiovascular system is responsible for supplying blood oxygen to every organ in your body, your brain included,” she said.

“The brain might be a small proportion of your overall body weight, but it uses 40 per cent of the blood oxygen from around your body.

“If your brain isn’t getting enough oxygen-rich blood, you’re more likely to have mini-strokes.”

The Australian Imaging, Biomarker and Lifestyle Flagship Study of Ageing has been scanning the brains of 1500 adults for a decade to look for the cognitive, health and lifestyle clues to predict who will develop Alzheimer’s disease.

“Irrespective of what your risk factors are, what your past history has been and how your thinking skills are at the moment, you’re certainly not going to do any harm by investing in your health, fitness and cognitive stimulation,” study coordinator Dr Robertson said.

The “vascular brain burden” — how impaired blood vessels cause dementia — is another angle being investigated at the Florey as part of the $6 million national research project.

Project lead Associate Professor Amy Brodtmann said a third of people who had a stroke developed dementia.

She said brain scans showed these people had higher rates of brain shrinkage, often in areas distant from where the stroke occurred. People with type 2 diabetes also had greater brain shrinkage, giving them a greater risk of dementia.

A study of 135 Victorian stroke patients tracked their physical activity for a week and measured their brain structure and cognitive performance.

Those who were more physically active performed better on those tasks and had stronger connections in the brain.

Now Florey wants to test whether exercise can prevent the decline to dementia.

The team has enrolled the first dozen of 100 stroke patients in a trial on how taking part in a cardio-based or stretch-and-balance exercise program can prevent brain atrophy. “Exercise is one of the only neuroprotective things we have,” Assoc Prof Brodtmann said. “We now know that inactivity is equal to the risk factor for smoking, when it comes to brain health, and that is quite astonishing.”