As we age, it’s not uncommon to experience subtle changes in memory or mental sharpness. By the time many people reach age 40, they may begin to notice small lapses—forgetting items on a grocery list or walking into a room only to wonder why they entered. While many assume these signs point to serious conditions like Alzheimer’s disease, researchers say that for most people, these changes are simply part of the brain’s natural aging process.
What Really Happens to the Brain After 40?
According to Matt Huentelman, a professor at the Translational Genomics Research Institute in Phoenix, both processing speed and memory begin to decline with age. Huentelman leads MindCrowd, a free online cognitive test completed by over 700,000 adults, which explores how and why individual brain function varies.
Speaking to NPR, Huentelman shared insights from the project, including the discovery that some adults perform like individuals 30 years younger on memory and cognition tests. While genetics play a role, lifestyle choices appear to have a significant impact.
“These individuals can help us understand what it takes to maintain strong cognitive function well into older age,” Huentelman said.
The Habits That Keep the Brain Young
Initial findings from MindCrowd and other research point to simple yet powerful habits that support brain health:
- Consistent, high-quality sleep
- Regular physical activity
- Avoiding smoking
- Managing vascular health conditions like hypertension and diabetes
At the Brain Aging Conference in Miami, hosted by the McKnight Brain Research Foundation, experts emphasized sleep’s critical role in preserving brain function. Dr. Christian Agudelo explained that waking up at the same time daily and maintaining physical and social activity help build “sleep pressure”—a natural driver for falling into deep, restorative sleep.
The Link Between Vascular Health and Cognitive Decline
Dr. Charles DeCarli, a leading neurologist, highlighted how vascular risk factors like high blood pressure and diabetescan age the brain—even in individuals without a history of stroke or heart attack. His research shows that brain size, shape, and tissue quality tend to appear older in people with these conditions.
“The question is, if you have these diseases and they are well-controlled, will you have a younger-looking brain? And the answer seems to be yes,” said DeCarli.
The findings suggest that protecting the heart and circulatory system may directly contribute to preserving cognitive health, reinforcing the close relationship between physical and brain wellness.
