Committing to a consistent exercise regime from your mid-forties could dramatically reduce your chances of developing dementia, a major new study has concluded.
Dementia remains the UK's leading cause of death, and experts have long suggested that 45 per cent of cases could be prevented through earlier lifestyle interventions, including increased physical activity. The critical question of when exercise is most beneficial has now been addressed by researchers from Boston University.
The Groundbreaking Research
Led by Dr Phillip H. Hwang from the Department of Epidemiology, the team analysed data from 4,354 adults who were descendants of participants in the renowned Framingham Heart Study. Their objective was to determine how physical activity levels at different life stages influenced dementia risk.
The participants, all free from dementia at the study's start, were divided into three distinct age groups: 1,526 early adults (average age 37), 1,943 midlife adults (average age 54), and 885 late-life adults (average age 71). Researchers then tracked them for decades to see who developed the condition.
Striking Results on Activity and Risk
Over the lengthy follow-up periods—up to 37 years for the youngest group—567 people developed dementia. Of these, 369 cases were diagnosed as Alzheimer's Disease, the most common form of dementia that affects approximately 982,000 people in the UK.
The analysis yielded a clear pattern: activity levels in early adulthood showed no significant link to future dementia risk. However, the impact of exercise in midlife and later years was profound.
Using a self-reported Physical Activity Index (PAI), subjects were ranked from Q1 (least active) to Q5 (most active). The findings, published in the prestigious JAMA medical journal, revealed that:
- Those most active in midlife (Q5) had a 41 per cent lower risk of dementia compared to the least active (Q1).
- Those most active in late life (Q5) had a 45 per cent lower risk of dementia.
What This Means for Public Health
'We found that higher physical activity levels in midlife and late-life were associated with similar reductions in all-cause dementia and Alzheimer's Disease dementia risk,' stated Dr Hwang.
He emphasised that these insights could guide future public health campaigns, helping to 'delay or prevent dementia through timing interventions... during the most relevant stages of the adult life course.'
The study does have limitations, including a predominantly white participant pool, meaning the results may not be universally applicable. Furthermore, the reliance on self-reported activity data could lead to some inaccuracies.
This research adds significant weight to existing NHS advice, which recommends adults get at least 150 minutes of moderate-intensity exercise weekly. With sedentary lifestyles estimated to contribute to 70,000 deaths annually in the UK, the message to get moving has never been more urgent for long-term brain health.
