People at risk of dementia could reduce chance of condition through exercise

A new study suggests that individuals at risk of dementia could potentially decrease their chances of developing the condition by over a third if they maintain good health and fitness.

The research found a link between high "cardiorespiratory fitness" (CRF), achievable through regular exercise, and a 35% reduced risk of dementia among those considered at risk. Experts have suggested that "enhancing CRF could be a strategy for the prevention of dementia".

The study indicates that those in the "medium" risk group with better cardiorespiratory fitness may be able to reduce their risk of developing dementia by 35%. The research, published in the British Journal of Sports Medicine, analysed data from over 60,000 participants in the UK Biobank study.

At the beginning of the study, participants underwent several tests, including a fitness test to assess their CRF after a period on an exercise bike. The researchers explained that CRF refers to "the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria in order to meet the energy demands of physical activity". Participants also took several tests to evaluate their cognitive abilities, memory, and information processing speed.

Researchers also analysed their "polygenic risk scores" by looking at whether each person had any common genetic variants associated with Alzheimer’s disease and dementia risk. The group, who were an average age of 56 at the start of the study, were tracked for almost 12 years to see whether they were diagnosed with dementia.

During the follow-up period, some 553 people were diagnosed with dementia. After comparing the information, the researchers found that people with high CRF appeared to have a 40% reduced risk of dementia compared to people with low CRF.

They also discovered that people with high CRF who did develop dementia tended to develop it later in life compared to those who had low levels of CRF. And among people with a moderate or high polygenic risk score, high CRF "attenuated all dementia risk by 35%", they said.

The researchers, led by academics from Tianjin Medical University in China, said: "CRF may be used as a predictor of cognitive health" and that "enhancing CRF could be a strategy for the prevention of dementia, even among people with a high genetic predisposition for Alzheimer’s disease."

Dr Jacqui Hanley, head of research at Alzheimer’s Research UK, said: "According to the latest research, nearly half of dementia cases globally could be prevented or delayed by addressing 14 risk factors, and keeping active is one of them."

She further emphasised the potential benefits of physical fitness: "This new research highlights how good cardiorespiratory fitness, a key measure of overall physical health, could help lower the risk of developing dementia in the future."

But she added: "However, it is important to note that we don’t know if there is a direct link between cardiorespiratory fitness and reduced dementia risk, more research is needed to find out exactly how it effects the brain."