After 65, A Head Injury Was Linked To Higher Dementia Risk. Half Of Them Began With A Fall.

By Paul E. Bendheim, MD — Founder of BrainSavers; board-certified neurologist and Clinical Professor of Neurology, University of Arizona College of Medicine – Phoenix; author of The Brain Training Revolution: A Proven Workout for Healthy Brain Aging

Huang YQ, Vyas MV, Bronskill SE, Li Z, Guan J, Hoang PM, Tam A, Bayley M, Vincent C, Straus SE, Watt JA. "Rate of incident dementia and care needs among older adults with new traumatic brain injury: a population-based cohort study." CMAJ, volume 197, issue 33, pages E1067–E1077, October 6, 2025.

When I teach about the lobes of the brain, I walk through the big regions one at a time: the frontal lobes that plan and decide, the temporal lobes that hold your memory maker, the hippocampus, and the parietal and occipital lobes behind them. What I don't spend much time on is how to protect them. A large study published last fall in the Canadian Medical Association Journal makes a strong case that one of the most practical ways to protect your brain has nothing to do with your brain at all. It has to do with your feet.

What The Researchers Did

A team of Ontario researchers working with ICES, the province's health research institute, looked at the health records of older adults across the province over 16 years. They found people over 65, living in their own homes, who had a new traumatic brain injury. That's a blow to the head serious enough to bring them to an emergency department or into the hospital. Their average age was 77.

Then they matched each person with someone the same age and sex who had no head injury and who looked as similar as possible on other health measures. That gave them 132,113 matched pairs, more than 264,000 people in all, followed for as long as 17 years. The question was simple: after a head injury late in life, what happens next?

What They Found

About half of the head injuries came from falls. Across every age group, a fall was the single most common cause.

Dementia was diagnosed more often afterward. In the first five years after the injury, the rate of new dementia was 69% higher than in the matched group. After five years, it was still 56% higher. People who had a head injury were typically diagnosed with dementia about two years sooner.

The risk climbed with age. Among people 85 and older, the researchers estimated that about one in three would go on to develop dementia after a head injury.

Independence was affected too. People with a head injury were more likely to need home care, and their rate of moving into a long-term care home was 45% higher.

Some groups fared worse. Older women from lower-income neighborhoods developed dementia more often than men in the same neighborhoods, 29% compared with about 25%. People in smaller communities received less home care and were more likely to end up in long-term care.

Why The Lobes Matter Here

This is where brain anatomy becomes practical. Your brain sits inside a hard skull, and the floor of the skull under the front of the brain is not smooth. In a Traumatic Brain Injury (TBI), the brain moves inside that space, and the undersides of the frontal lobes and the tips of the temporal lobes are among the areas most vulnerable to bruising. Those are the regions that handle planning, judgment, and the formation of new memories.

The study doesn't tell us exactly why a head injury late in life is followed by more dementia. But it makes sense that a brain already working with less reserve has less room to absorb an injury to the very regions it relies on most.

What This Study Does Not Say

This was an observational study. It shows that a head injury was associated with more dementia afterward. It can't prove the injury caused it. The authors point out that the link may run in both directions: early memory problems that haven't been diagnosed yet can make a person more likely to fall. They also note that the records can miss mild dementia and can't separate its different types, and that injuries treated only at a clinic, without an emergency visit, weren't counted.

So this isn't a reason to fear every stumble. It's a reason to take fall prevention as seriously as you take your blood pressure.

The Good News: Falls Are Often Preventable

The lead authors, Dr. Yu Qing Huang and Dr. Jennifer Watt, put the opportunity this way: "One of the most common reasons for TBI in older adulthood is sustaining a fall, which is often preventable. By targeting fall-related TBIs, we can potentially reduce TBI-associated dementia."

I find that encouraging. Many of the things that lower your risk of falling are things we already practice in BrainSavers: strength, balance, and staying active. A stronger body is a steadier body, and a steadier body protects the organ you care most about.

For BrainSavers Participants

Take the balance work in our Time to Move sessions seriously. It isn't a warm-up for the "real" exercise. It may be some of the most protective work you do. And if you've had a fall recently, or you've noticed yourself feeling less steady, mention it to your healthcare provider. A fall is worth reporting even when nothing seems broken.

Three Things You Can Do This Week

• Practice your balance every day. Stand behind a sturdy chair and hold the back lightly. Try standing on one foot for 10 seconds, then the other. Hold on with both hands if you need to.

• Walk through your home with fresh eyes. Look for loose rugs, cords across walkways, dim hallways, and stairs without a handrail. Fix one of them this week. A night light on the way to the bathroom is a good place to start.

• Ask about your medicines and your eyes. Some medications can make you dizzy or drowsy. Ask your healthcare provider or pharmacist to review yours, and keep your eye exams up to date.

You are not simply a passenger on the journey of your own brain aging. Sometimes the best thing you can do for your brain is make sure you stay on your feet.

This article is for general educational purposes and is not medical advice. Talk with your own healthcare provider before making changes to your health, exercise, or medication routine.