A new long-term study from the Johns Hopkins Bloomberg School of Public Health has found that many cases of dementia before the age of 80 may be preventable.
By treating common health issues like high blood pressure, diabetes, and smoking earlier in life, it may be possible to reduce the risk of developing dementia by up to 44%.
This research, published in JAMA Neurology, followed over 12,000 adults in the U.S. for 33 years. Participants were from four different communities and ranged in age from 45 to 74 when their blood pressure, blood sugar, and smoking habits were first recorded.
The study tracked who went on to develop dementia and compared their risk based on these common vascular (blood vessel-related) problems.
Dementia, a condition that causes memory loss and problems with thinking and decision-making, is often linked to aging.
However, it’s becoming clear that it doesn’t happen overnight. Long before someone is diagnosed, small changes may already be happening in the brain—especially if blood vessels are damaged.
This type of damage is called cerebral small vessel disease (CSVD), where tiny blood vessels in the brain narrow, harden, or become blocked. When brain cells don’t get enough oxygen, they start to weaken and die.
The symptoms of this damage—like forgetfulness or confusion—can look similar to normal aging, making it hard to notice until it gets much worse.
What’s more, many people with dementia also show signs of both Alzheimer’s disease and vascular damage, which makes it difficult to say exactly how much is caused by blood vessel problems.
That’s why this study is so important. It aimed to find out how much dementia could be prevented if vascular problems were managed earlier. The results were striking.
People who had high blood pressure, diabetes, or smoked in their midlife (ages 45–64) had a significantly higher chance of getting dementia by age 80. In fact, up to 44% of dementia cases in people aged 65–74 could be linked to these conditions.
But after age 80, these same risk factors didn’t seem to matter as much—only 2% to 8% of dementia cases after age 80 were linked to them.
The study also looked at different groups of people and found that some were at even higher risk. For example, people who did not carry the APOE ε4 gene—a gene known to raise the risk of Alzheimer’s—were more likely to be affected by vascular-related dementia.
In this group, as much as 61% of dementia cases in people aged 65–74 could be tied to treatable health issues. Higher risks were also found in Black participants (up to 52.9%) and women (up to 51.3%).
These findings highlight how powerful it can be to treat high blood pressure, diabetes, and stop smoking—especially before the age of 75. Taking care of these health problems may be one of the best ways to reduce your risk of dementia.
In conclusion, this study suggests that nearly half of dementia cases before age 80 could be avoided with better control of vascular health. While age and genetics do play a role in dementia, there is now strong evidence that preventing and treating common health conditions in midlife and late life can make a big difference.
For anyone looking to protect their brain as they age, focusing on heart and blood vessel health is a smart place to start.
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The research findings can be found in JAMA Neurology.
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