Walking for more than 5,000 steps per day may reduce Alzheimer’s risk – study

Walking for more than 5,000 steps per day may slow down cognitive decline and the build-up of a protein linked to Alzheimer’s disease, research suggests.

Experts said the new 14-year study is one of the first to explore the relationship between different levels of activity and key markers of Alzheimer’s disease.

They said the findings are also important because they suggest people who already have the earliest signs of Alzheimer’s in their brains may benefit from modest amounts of exercise to slow down the disease.

For the new study, published in the journal Nature Medicine, experts from Harvard analysed data from 294 people aged 50 to 90.

These people had proteins called amyloid and tau present in their brains were not experiencing symptoms of dementia.

All were taking part in the Harvard Aging Brain Study and wore pedometers to measure physical activity such as walking.

They also underwent brain scans and annual cognitive assessments for up to 14 years.

The study found that higher levels of activity was linked to a slower decline in thinking and memory skills related to amyloid proteins in the brain, which can be a sign of Alzheimer’s.

There was a slowing in the build-up of the protein called tau, which is also seen in Alzheimer’s.

Even modest activity (3,001–5,000 steps per day) was linked with a notable slowing of tau accumulation and cognitive decline, experts said, though 5,001 to 7,500 steps per day appeared more beneficial.

Professor Tara Spires-Jones, group leader in the UK Dementia Research Institute, said further studies were needed, but added: “This study (from) Harvard Medical School shows taking over 5,000 steps a day is associated with slowing of cognitive decline and slowing the build-up of Alzheimer’s disease pathology in the brain.

“The study is well-conducted, and the data are an important advance as they indicate that people who already have early Alzheimer’s disease pathology in their brains may still benefit from taking even modest amounts of activity (over 3,000 steps per day).”

She added: “On balance, the data in the field indicate that keeping physically active is good for your brain but is not a guarantee of preventing or slowing dementia.”

Charles Marshall, professor of clinical neurology at Queen Mary University of London, said the research could not determine whether the people doing more exercise were also healthier in other ways, nor whether the development of Alzheimer’s disease changes are influencing activity levels.

But he added: “This research provides strong evidence that moderate levels of physical activity are associated with slower progression of the earliest stages of Alzheimer’s disease, and that this is linked to slower accumulation of tau protein, which is an important cause of brain cell loss.”

Dr Richard Oakley, associate director of research and innovation at Alzheimer’s Society, said: “One in three people born today will develop dementia in their lifetime, but evidence shows we can reduce our risk of getting the condition.

“This study reinforces the message that what’s good for our heart is also good for our head and that being more active can support brain health.

“However, because this is an observational study, we can’t draw a conclusive link between step count and changes to cognition or potential signs of Alzheimer’s disease in the brain.

“The study followed people with raised levels of amyloid in their brain – a potential early sign of Alzheimer’s – but who were not cognitively impaired.

“We don’t know if these people went on to develop dementia or whether walking 5,000-7,000 steps a day might reduce the risk of or prevent the condition.

“We would encourage everyone to exercise regularly if they can. Other steps like eating a healthy balanced diet, not smoking, drinking less alcohol and keeping on top of health conditions, such as diabetes or high blood pressure, can also help reduce our risk of getting dementia.”

Dr Julia Dudley, head of research at Alzheimer’s Research UK, said: “Research has shown that up to 45% of dementia cases could be prevented by addressing factors that may increase our risk, including physical inactivity.

“This study adds to existing knowledge that being active is good for brain health and could help slow memory and thinking decline as we age.”