Sedentary lifestyle accelerates rate at which the brain shrinks

by Ben Spencer for Daily Mail:

If you require a dig in the ribs to get off the sofa, the latest research may give you the encouragement you need.

For scientists have found that failing to exercise may shrink your brain.

A major study concluded that people with poor levels of physical fitness in their 30s and 40s were likely to have smaller brains two decades later.

Experts think that a sedentary lifestyle accelerates the ageing process, speeding the rate at which the brain shrinks.

The researchers, from Boston University School of Medicine, said staying fit in middle age is crucial to staying healthy in later life.

Brain shrinkage is a major factor in early cognitive decline, dementia and even premature death.

The scientists analysed medical data from nearly 1,600 people who were tracked over 20 years.

The participants underwent a fitness test on a treadmill in the late 1970s and early 1980s, when they were each aged between 31 and 49.

Each volunteer ran on the treadmill until their heart reached a certain heart rate, with the fitter participants taking longer to hit the target than those who were less fit.

Two decades later, between 1998 and 2001, the volunteers underwent a series of MRI brain scans and neurological tests.

The scientists, whose results are published in the Neurology medical journal, found that those people who had the lowest fitness levels initially were most likely to have smaller brains 20 years later.

Study author Dr Nicole Spartano said: ‘We found a direct correlation in our study between poor fitness and brain volume decades later, which indicates accelerated brain aging.’

All brains shrink with age, a natural part of the ageing process.

But the new results suggest that exercise levels determine the rate at which this happens.

On average, the authors found that the participants’ total brain volume shrank by roughly 0.2 per cent a year.

But those who were less fit when they were in their 30s and 40s saw their brains shrink faster.

For every 20 per cent reduction in fitness score below average in the initial exercise test, the participants displayed an additional 0.2 per cent brain shrinkage - the equivalent of an entire additional year of ageing.

This is thought to be because physical fitness reduces blood pressure, decreasing the strain on the brain.

People who were 20 per cent less fit were able to process less oxygen, had a heart rate of 17 beats per minute higher than average, and blood pressure of 14 points above normal.

As well as impacting on the size and health of the brain, each of these factors also increases the risk of heart disease and stroke.

Dr Spartano added: ‘While not yet studied on a large scale, these results suggest that fitness in middle age may be particularly important for the many millions of people around the world who already have evidence of heart disease.’

NHS guidelines which suggest adults should undertake either 150 minutes of moderate activity or 75 minutes of vigorous activity each week.

Source: http://dailym.ai/1TgJO9w