London: Leading an active lifestyle, particularly before the age of 50, changes the brain in a way that could prevent dementia. According to a new study, the findings suggest this could be down to exercise helping to preserve the volume in the area of the brain that contributes to thinking and memory, researchers said.
According to Bahrain News Agency, the team collected information on how many times a person took part in activities such as walking, swimming, cricket, rugby, and football over the course of three decades, before and after they turned 50. Brain scans taken when participants were aged 70 were then analyzed.
The study found exercising throughout life was "associated with better cognitive functioning at age 70, even in those with early markers of Alzheimer's disease", with the benefits more pronounced in women.
People who reported exercising once or more a month before the age of 50 tended to have less shrinking in the hippocampus, the part of the brain that helps with learning and memory.
"It's a really important part of the brain, and we're showing that it's actually larger," Dr. Sarah-Naomi James added. "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."
The benefits of activity before the age of 50 could be linked to the intensity of exercise and the kinds of activity people were doing in their 30s and 40s, Dr. James said, although more research is needed to confirm this.
While future studies may "shed light on the mechanisms of physical activity as a potential disease-modifying intervention", Dr. James said 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 it. We call it the mechanisms, the pathways - what is it about being physically active that is good 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 are 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."
According to Alzheimer's Research UK, which funded the study alongside the Medical Research Council, about 982,000 people are estimated to be living with dementia in the UK. This figure is projected to rise to more than 1.4 million in 2040.
"It's never too late, it's never too early. People who are active, it's really good for your brain," Dr. James said. "But actually, even if you are later in life and even starting to have disease symptoms, it could still be beneficial."
She said she would like policies to emphasize "the importance of access to physical activity throughout life". "We can think about policies around schools, which we think are really important, but especially thinking about it throughout life, when we are in our early, when we start 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, said: "Dementia is not just an inevitable part of aging, 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 of developing it, including keeping ourselves active and looking after our heart health, challenging our brains and keeping ourselves connected to the people around us. The evidence shows that it's never too early or late to start making positive changes."