Being aerobically fit in middle age may reduce Alzheimer’s and dementia risk, study says

Regular aerobic exercise may reduce the risk of dementia, including Alzheimer’s disease, according to a new study. The research, led by Professor Weili Xu from the Aging Research Center at Karolinska Institute, highlights the importance of cardiovascular fitness for brain health.

“Our study shows that staying fit reduces dementia risk, even for those genetically predisposed to Alzheimer’s,” Xu explained. “Improving fitness gradually offers a simple way to protect brain health.”

The findings, published in the British Journal of Sports Medicine, show that participants with the highest fitness levels had better cognitive function. Their relative risk for dementia was only 0.6% compared to less fit individuals. This advantage delayed dementia onset by 1.5 years on average.

Fitness as a “Brain Booster”

The study revealed even greater benefits for people at genetic risk for Alzheimer’s. Those with the best fitness levels had a 35% lower relative risk of developing the disease.

“Genes aren’t destiny,” said Dr. Richard Isaacson, a preventive neurologist and director of research at the Institute for Neurodegenerative Diseases. “Exercise is like a miracle drug for the brain. It boosts memory and delays dementia.”

Aerobic activities such as walking, jogging, swimming, and cycling improve cardiorespiratory fitness. This type of fitness enhances oxygen flow in the heart and lungs, which helps sustain physical activity and supports brain health.

Lifelong Fitness Matters

The study tracked over 61,000 adults aged 39 to 70 from the UK Biobank. Researchers tested participants’ fitness, cognitive abilities, and genetic risk factors. They followed up 12 years later to assess dementia risk.

“Higher fitness levels improved memory, cognitive speed, and task execution,” Isaacson explained. “The more fit a person was, the greater the benefits.”

Fitness declines with age. Inactive adults lose 3% to 6% of fitness per decade starting in their 20s. This rate increases to over 20% per decade in the 70s, making regular exercise crucial for long-term health.

Key Takeaways and Recommendations

Although the study was observational, cardiologist Dr. Valentin Fuster emphasized its significance. “Low fitness often coincides with conditions like hypertension, diabetes, and obesity. These are risk factors for dementia,” he said.

Fuster stressed the connection between heart and brain health. Protecting cardiovascular fitness also supports cognitive function and may slow Alzheimer’s progression.

Experts recommend 30 minutes of aerobic exercise at least five days a week. Activities like brisk walking, hiking, swimming, and team sports help build fitness. High-intensity interval training is another effective option.

In addition to lowering dementia risk, exercise supports weight management, mood stabilization, and better sleep. It also promotes longer, healthier lives.