It’s not too late to protect your brain from dementia

In the quest to better understand the effects of ageing on the brain and the causes of brain impairment, scientists have looked at diet, lifestyle and genetic factors. But they keep coming back to one thing – and the good news is it’s something we can all aim for.

A study of the brains of mice shows that structural deterioration associated with old age can be prevented by long-term aerobic exercise starting in mid-life.

Gareth Howell, Ileana Soto and their colleagues at The Jackson Laboratory in Bar Harbor, Maine, found that structural changes that make the blood–brain barrier leaky and result in inflammation of brain tissues in old mice can be mitigated by getting the animals to run regularly.

This is one of numerous explorations of  how and why exercise helps prevent dementia in humans.

Another study published this month shows that people who exercise regularly have longer telomeres, the tiny caps found on the end of DNA strands. These are believed to protect the DNA from damage during cell division and replication.

Physical activity is already known to slow cognitive decline in humans as well as in mice. To investigate the impact of long-term physical exercise on the brain changes seen in the ageing mice, the researchers provided the animals with a running wheel from 12 months old (equivalent to middle aged in humans) and assessed their brains at 18 months when the risk of Alzheimer’s disease is greatly increased.

Young and old mice alike ran about two miles per night, and this physical activity improved the ability and motivation of the older mice to engage in the typical spontaneous behaviours that seem to be affected by ageing.

The researchers concluded that a long-term exercise program is capable of preventing brain deterioration associated with old age.

Dr Howell says, “In this day and age, with so many distractions and conveniences, it is easy to fall into a lifestyle that does not include enough exercise. With an aging population, I hope our study helps in encouraging a healthy lifestyle that includes exercise.”

He adds, “For those that are unfortunately unable to exercise, our study provides insight into a possible mechanism by which exercise may benefit the ageing brain and may one day lead to improved treatments for age-related cognitive decline, Alzheimer’s disease and other neurodegenerative disorders.”

Do you have an exercise program? Could you step it up a little to protect your brain?