Dementia Risk Starts In Childhood And Even Infancy, Scientists Warn

Though not all of our dementia risk is in our control, medical journal The Lancet has said that almost half of our likelihood of developing the condition is down to 14 potentially “modifiable” lifestyle factors. 

These include controlling LDL cholesterol, preventing and treating hearing loss, and staying physically active. 

These guidelines are heavily focused on those in midlife (aged 40-60), with the only comment for “early years” being that those who got a better education as kids were 5% less likely to develop dementia.

But writing to The Lancet in 2024, scientists in the Next Generation Brain Health (NGBH) team say they have identified “several high-priority modifiable factors in young adulthood and devised five key recommendations for promoting brain health, ranging from individual to policy levels.”

The researchers looked at data from 15 countries

Looking at data from 15 countries across six continents, the researchers found that many of the risk factors for dementia started younger than expected. 

“80% of adolescents living with obesity will remain this way when they are adults,” the group told The Conversation.

“The same applies to high blood pressure and lack of exercise. Similarly, virtually all adults who smoke or drink will have started these unhealthy habits in or around adolescence.” 

Vision loss, air pollution, and the aforementioned lack of education are less studied in young people, particularly as they relate to dementia risk, they argue in their Lancet paper.

They point out that a person’s cognitive ability at 11 is linked to their risk of dementia at 70; more and more research is showing associations between everything from childhood neglect to maternal smoking and the condition.

That means dementia risk could start as far back as infancy. But, the researchers argue, many dementia studies begin at midlife, skewing the recommendations towards an older crowd. 

“Young adults (aged 18–39 years) are a neglected population in dementia research and policy making despite being highly exposed to several known modifiable risk factors,” the group shared.

Isn’t that unfair?

It’s frustrating to think that a lot of the modifiable risk factors for dementia may have begun before you could agree to them (though we don’t yet know exactly how much, or by what age; that’s what the experts argue we should study).

But even among adults, the existing risk factors for midlife are not exactly in our full control. They include things like having depression, getting a traumatic brain injury, and hearing loss. 

The point is not to depress people out of trying to lower their dementia risk as soon as they can, the researchers say.

Instead, it is about encouraging both better policy (like making education, including post-secondary education, free) and improved community care (like ensuring people with hearing loss remain socially included) alongside personal self-improvement (like wearing a helmet when needed). 

But pretending not to notice, or failing to act in a coordinated way upon, increased dementia risk for younger people will not help, the NGBH say. 

And, as they told The Conversation, “while it’s never too late to take steps to reduce your risk of dementia, it’s also never too early to start.”