Dementia, a form of cognitive decline that interferes with normal daily living, affects approximately 50 million people worldwide. Findings from a recent study suggest that regular physical exercise can reduce the risk of developing dementia.

Dementia commonly occurs in older age and is characterized by a progressive loss of memory, executive function, and reasoning. Approximately 70 percent of all dementia cases are due to Alzheimer’s disease. Previous research has demonstrated that the incidence of dementia is influenced by non-modifiable risk factors, such as increasing age, ethnicity, and the presence of a genetic variant known as APOE4.

Researchers are less certain about modifiable factors that may alter dementia risk, including health behaviors such as exercise. The current retrospective cohort study investigated which individuals developed dementia and the factors associated with its incidence.

The study involved 206,073 people over the age of 50 years who were enrolled in the Health Check Ubon Ratchathani Project in Thailand. The authors of the study questioned participants about their medical and personal history, including the use of medications and exercise habits. Six years later, investigators reviewed the participants' electronic medical records for the incidence of physician‐diagnosed dementia. They found that a lack of physical exercise was associated with an increased risk of developing dementia in a dose-dependent manner. Exercising three to five days per week reduced the risk of dementia by 37 percent as compared to no physical exercise, while exercising more than five days per week reduced dementia risk by 59 percent.

These findings suggest that physical exercise at least three days a week can reduce the risk of developing dementia. Further clinical trials with longer follow-ups are needed to confirm the impact of lifestyle factors on dementia risk.

• Link to the study abstract.