Lifestyle factors linked to higher and lower dementia risk
Research indicates that up to 45% of dementia risk may be influenced by modifiable habits, with smoking, high red-meat intake and untreated hypertension among the risk-increasing behaviors, while regular exercise, social interaction and adequate daylight exposure appear protective.
A commission cited by The Lancet estimates that as much as 45% of dementia risk could be affected by lifestyle choices. Studies highlighted several habits that may increase the likelihood of developing dementia. Current smokers faced a 31% higher risk, particularly for vascular dementia, while former smokers did not show the same elevation except for some male ex-smokers. High consumption of red and processed meat was associated with higher risk and lower cognitive scores, prompting researchers to suggest reduced intake in dietary guidelines. Not receiving the shingles vaccine in older age may raise risk by up to 16%, according to research linking vaccination to lower dementia incidence. Both short and long sleep durations outside the 7-8 hour range were linked to increased risk, though the direction of causality remains unclear. Untreated high blood pressure was linked to a 36% higher incidence of Alzheimer’s disease compared with normal blood pressure, and a 42% increase relative to treated hypertension; medication use was associated with reduced risk.
Conversely, several behaviors were associated with lower dementia risk. Frequent egg consumption, which provides choline, has been linked to reduced Alzheimer’s risk. Social engagement may delay dementia onset by up to five years and cut risk by 38%, while social isolation can raise risk by about 60%. Physical activity as modest as 3,800 steps per day was linked to a 25% lower risk, with optimal benefits observed around 7,000 brisk steps or meeting recommended exercise guidelines. Regular reading was associated with reduced cognitive decline, especially when reading more than an hour daily. Exposure to at least 42 minutes of bright daylight each day correlated with a 16% risk reduction, outperforming several other risk factors. Continuing education in adulthood lowered risk by 19% within five years, and informal brain-training activities such as speed-processing exercises or birdwatching may also be beneficial. Protecting hearing was noted as another factor potentially influencing dementia risk.