Dementia and Alzheimer's disease are two of the most common causes of cognitive decline in older adults. Dementia affects approximately 47 million individuals globally with projections of 130 million by the year 2050. Late-onset Alzheimer's disease is the most common form of dementia, accounting for approximately 75% of all cases and is characterized by a progressive decline in cognitive function, memory, and cerebral volume. While there currently is no cure for these conditions, there is solid evidence that exercise can reduce your risk of dementia and Alzheimer's. Here are just a few examples of recent research on the link between exercise and cognitive health.
A 2018 study conducted in Sweden followed 1,462 Swedish women for 44 years. Those who exercised regularly were one-tenth as likely to suffer dementia as those who did not exercise. If the more fit study participants did develop dementia, they developed it an average of 11 years later than women who were less fit (at age 90 instead of age 79).
Researchers followed nearly 6,500 adults, aged 61-78, who wore exercise trackers for three years. Their study, published in 2021, found that those adults who exercised regularly had a 36% lower risk of memory loss as well as better memory and executive function.
A 2022 study https://alz-journals.onlinelibrary.wiley.com/doi/abs/10.1002/alz.12530 found that exercise, late in life, appears to protect the aging connections between brain cells - the synapses where memories are made. According to the lead author of the study, there is a 30-80% reduced risk of dementia in people who exercise.
Data from two generations of middle-aged and older adults followed for the Framingham Heart Study in the United States showed that each additional hour spent in light-intensity physical activity is associated with larger brain volume, equivalent to approximately 1.1 years less brain aging. Achieving 10,000 or more steps per day is associated with higher brain volume compared to those achieving fewer than 5,000 steps per day.
A 2011 meta analysis and a subsequent 2021 meta analysis of hundreds of research articles showed that older people who exercise lose less brain function, have larger hippocampal brain size (better memory), less loss of brain tissue, better spatial memory, better communication between brain cells, and improved ability to learn new facts.
Tips for Maintaining a Youthful Brain
In addition to exercise, an individual's diet and lifestyle over several decades appear to be key determinants in whether or not someone will develop Alzheimer's. In a massive study published in 2021, researchers monitored over 300,000 people, aged 50-73, for eight years to see who did and did not develop dementia. They found that the following healthy lifestyle behaviors reduced your chance of dementia/Alzheimer's:
Eating a healthy diet with more fruits and vegetables and less processed meat and refined grains
Meeting physical activity guidelines of 150 or more minutes a week of moderate-to-vigorous physical activity
Sleeping 6 to 9 hours each day
Drinking alcohol in moderation
Not smoking
Having a body mass index (BMI) under 30
The good news is that you have the ability to significantly reduce your risk of Alzheimer's and dementia. The saying, "Genetics loads the gun, but lifestyle pulls the trigger" is very true in this case. If you want to maintain a youthful brain, get serious about prioritizing sleep, push yourself to exercise consistently, ditch the cigarettes, and embrace a no-nonsense, healthy diet. Take control of your brain health and reap the rewards of a razor-sharp mind well into your later years.
For in-depth discussions on this subject, check out the following podcasts:
The Drive with Dr. Peter Attia - #236 - Neurodegenerative disease: pathology, screening, and prevention
The Neuro Experience Podcast - The Real Cause of Alzheimer's Disease and What You Can Do About it
The Huberman Lab Podcast - Dr. Rhonda Patrick: Micronutrients for Health and Longevity