The free workout that can slash dementia risk factor by up to 76% – and 5 other cheap ways to ward off the killer

IT'S official: exercise can slash your risk of dementia.

But before you drag yourself to the gym, here’s the catch – not any old workout will be effective.

Scientists from the University of Bristol say the key here is aerobic exercise – and the best part? It’s free!

Aerobic exercise, or cardio, is any activity that gets your heart pumping and your breathing faster. Think running, cycling, or even a brisk walk.

They found that regular cardio reduced signs of Alzheimer’s - the most common form of dementia - in rats’ brains, including harmful plaques.

Up to 40 per cent of cases are linked to preventable causes, according to Alzheimer’s Research UK, such as smoking, obesity or physical inactivity.

"While physical exercise is known to reduce cognitive decline, the cellular mechanisms behind its neuroprotective effects have remained elusive—until now," study co-author Augusto Coppi, senior lecturer in veterinary anatomy, said.

"This research highlights the potential for aerobic exercise to serve as a cornerstone in preventive strategies for Alzheimer's."

Alzheimer’s is thought to be caused by build-ups of proteins in the brain, including tau and amyloid.

There is currently no cure for the disease, although promising drugs to slow down its progress are currently in trials.

More than 3million Brits have cancer currently, with experts expecting rates to reach 5.3million by 2040.

Previous research suggested Just one or two workouts a week - 'weekend warrior' style - could be just as good, potentially better, than frequent bouts of exercise for slowing down mental decline.

Colombian researchers found that the risk of cognitive decline reduced by 15 per cent in those who exercised once or twice per week and by 10 per cent in the "regularly active" who exercised more often.

The latest study, published in , focused on the hippocampus, the area responsible for memory and learning, and looked at how aerobic exercise affects Alzheimer’s-related brain changes.

Alzheimer’s disease primarily affects memory, thinking, and behaviour.

Early symptoms include memory loss, confusion, and poor judgment.

As the disease progresses, it can cause severe cognitive decline, including difficulty recognising faces, and movement issues.

Amyloid plaques form between brain cells, disrupting communication, while tau tangles build up inside cells and cause damage.

Iron accumulation in oligodendrocytes is also linked to Alzheimer’s, as excess iron can lead to oxidative stress, which harms nerve cell function.

The researchers found that aerobic exercise helped reduce these harmful changes.

"Iron overload in the oligodendrocytes is an inducer of ferroptosis in aged brains," they explained.

Rats that exercised regularly saw a 63 per cent reduction in tau tangles, a 76 per cent decrease in amyloid plaques, and a 58 cent reduction in iron buildup, compared to those that didn’t exercise.

Exercise also boosted communication between brain cells, helping restore balance in brain function as it ages and becomes more vulnerable to dementia.

The researchers now hope to test if these findings apply to humans.

"Our data suggest the beneficial effects of physical exercise in Alzheimer's disease," they concluded.