Maintaining a regular exercise routine from your mid-forties could reduce your risk of developing dementia, according to a new study from Boston University.
Dementia is the UK’s leading cause of death, and previous research has suggested that up to 45% of cases could be prevented through early lifestyle changes, including physical activity. However, it was unclear at which stage of life exercise provides the most benefit.
Led by Dr. Phillip H. Hwang from the Department of Epidemiology, researchers analyzed data from 4,354 adults who were offspring of participants in the Framingham Heart Study. Participants, none of whom had dementia at the start, were divided into three groups: early adulthood (average age 37), midlife (average age 54), and late life (average age 71). Follow-up periods varied: 37 years for early adults, 25 years for midlife, and 14 years for late-life participants.
During the study, 567 participants developed dementia, 369 of whom were diagnosed with Alzheimer’s Disease, the most common form of dementia affecting nearly 1 million people in the UK.
The study found no significant link between physical activity in early adulthood and dementia risk. However, being physically active in midlife or late life was associated with a markedly lower risk. Participants in the highest activity group during midlife had a 41% lower risk of developing dementia compared to the least active, while those active in late life had a 45% lower risk. The results were similar specifically for Alzheimer’s Disease.
Physical activity was measured using the Physical Activity Index (PAI), which considers hours spent sleeping and in sedentary, light, moderate, or heavy activity. Participants were categorized into five groups, from least active (Q1) to most active (Q5).
Dr. Hwang noted, “Higher physical activity levels in midlife and late life were associated with similar reductions in all-cause dementia and Alzheimer’s disease risk. These findings may guide future interventions to delay or prevent dementia by targeting key stages in adult life.”
The study has limitations: most participants were white, which may affect generalizability, and activity levels were self-reported, which could lead to inaccuracies.
Experts have long warned that sedentary lifestyles increase the risk of numerous health problems, including obesity, type 2 diabetes, cancer, and premature death. The NHS recommends adults get at least 150 minutes of moderate-intensity exercise—or 75 minutes of vigorous activity—each week.
