This is how physical exercise between the ages of 45 and 65 helps prevent Alzheimer's.

Increasing physical activity between the ages of 45 and 65 could be key to preventing Alzheimer's, according to a new study published in the journal Alzheimer's & Dementia . The research, led by the Barcelona Institute for Global Health (ISGlobal) and the Barcelonaβeta Brain Research Center (BBRC), highlights that inactivity at this stage of life can be harmful to the brain.

The study reveals that up to 13% of Alzheimer's cases worldwide could be attributed to physical inactivity. The World Health Organization (WHO) recommends at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week, and the results of the study underscore the importance of following these guidelines, especially in middle age.

Researchers analyzed data from 337 individuals in the ALFA cohort with a family history of Alzheimer's. Over four years, their physical activity levels were assessed using questionnaires, and neuroimaging tests were performed to observe changes in brain structure and function.

"We observed that those who increased their physical activity to the levels recommended by the WHO showed less accumulation of beta amyloid, a protein associated with the onset of Alzheimer's disease," explains Müge Akıncı, a doctoral researcher at ISGlobal and BBRC, and first author of the study. "They also had greater cortical thickness in brain regions related to memory."

The benefits also appeared to depend on the amount of exercise: the greater the increase in activity, the greater the reduction in beta amyloid load. Even those who didn't reach the recommended levels but avoided a complete sedentary lifestyle showed improvements in brain health.

"These findings demonstrate that any level of movement is better than none and reinforce the need to promote exercise as a preventative tool," says Eider Arenaza-Urquijo, the study's principal investigator. "Promoting active habits in middle age could have a significant impact on the fight against Alzheimer's," she concludes.