Starting this habit early in your life can dramatically reduce dementia risk, study finds

A new study reveals that staying active throughout life, particularly before the age of 50, could play a vital role in preventing dementia. Researchers believe exercise helps maintain the volume in key areas of the brain responsible for memory and thinking, potentially staving off cognitive decline.

The findings suggest that lifelong exercise might also lessen the impact of Alzheimer’s markers, such as the buildup of amyloid protein, even in individuals showing signs of the disease.

The study, based on data from Insight46, a sub-study of the National Survey of Health and Development, tracked 5,362 participants born during one week in March 1946 across England, Scotland, and Wales, Bristol Live reports.

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The analysis included 468 people, all aged 70 at the time. Dr. Sarah-Naomi James, from the UCL Dementia Research Centre and the MRC unit for lifelong health and ageing at UCL, explained to the PA news agency: “When we’re thinking about brain changes, one of the biggest predictors of how big your brain volume is is age.

“So the fact that we’ve got exactly the same people born in the same week takes that into account.”

Over a period of three decades, researchers gathered data on participants’ involvement in activities like walking, swimming, cricket, rugby, and football, both before and after they turned 50. The brain scans taken at age 70 were then carefully analyzed.

The study revealed that consistent exercise throughout life was “associated with better cognitive functioning at age 70, even in those with early markers of Alzheimer’s disease,” with women showing particularly notable benefits.

Those who engaged in physical activity at least once a month before reaching 50 were found to have less shrinkage in the hippocampus, a brain region crucial for learning and memory. Dr. James highlighted its significance, stating: “It’s a really important part of the brain, and we’re showing that it’s actually larger.

“We call it preservation of this area of the brain that is usually starting to decline and that is responsible for the early signs of dementia.”

Dr. James suggested that the benefits of physical activity before the age of 50 might be tied to the intensity of exercise and the types of activities people engaged in during their 30s and 40s, though further research is necessary to confirm this.

While future studies could “shed light on the mechanisms of physical activity as a potential disease-modifying intervention,” Dr. James noted that her team’s findings, published in Brain Communications, “add a little bit about the question of how, or why.”

“Why is exercise good for us? It makes intuitive sense, but we still actually don’t know lots about, we call it the mechanisms, the pathways – what is it about being physically active that is good for for our brain,” she added.

“For instance, we look at something like dementia and we say ‘there’s a pattern that we can see replicated lots of times, people who are physically active, they they’re less likely to have dementia’.

“But what we’re showing is that even before they have dementia, they are able to tolerate and keep their cognitive function, regardless of if they start to have the early signs in the brain. It might be to do this preservation of the specific area of the brain. And then also you’re able to tolerate the pathology for longer.

“So it means that perhaps we’re not changing the disease itself, but we’re changing perhaps when you might start to develop symptoms.”

Alzheimer’s Research UK, which co-funded the study with the Medical Research Council, estimates that around 982,000 people in the UK are living with dementia, a number projected to exceed 1.4 million by 2040. Dr. James emphasized, “It’s never too late, it’s never too early. People who are active, it’s really good for your brain.

“But actually, even if you are later in life, and even starting to have disease symptoms, it could still be beneficial.”

She added that she would like policies to emphasise “the importance of access to physical activity throughout the life”.

“We can think about policies around schools, which is really important, but especially thinking about throughout the life – the early 30s, when people are starting to juggle careers and families. Then thinking about the 50s, and health is changing but we need to adapt and be physically active,” Dr James said.

David Thomas, head of policy and public affairs at Alzheimer’s Research UK, added: “Dementia is not just an inevitable part of ageing, and finding ways to prevent people from ever developing it is a vital part of our mission for a cure.

“While there is no sure-fire way to prevent dementia, there are some things within our control that can reduce our risk, including keeping active and looking after our heart health, challenging our brains and keeping connected to the people around us.

“The evidence shows that it’s never too early or late to start making positive changes.”

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