Dementia is often associated with older people, but it doesn’t appear in a vacuum.
Some risk factors may begin before we are born, while others appear as we move from childhood into early adulthood.
According to research, this may be the best time to begin intervention.
Previous research has identified multiple modifiable dementia risk factors, but changing them after neurodegeneration has occurred is not very helpful, encouraging researchers to look for actions in the earliest moments of life that might one day have an impact.
Related: Dementia in young people is often overlooked. Here are 5 key reasons.
A 2023 study by researchers in Sweden and the Czech Republic found a number of birth factors associated with a slightly increased risk of developing dementia later in life.
While some factors, such as sharing the womb with twins, are beyond anyone’s control, others, such as shorter intervals between births and getting pregnant after age 35, may influence a parent’s decision-making.
You can view a video summary of some of the research in this article here:
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Another study published in late 2024 looked at risk factors in young people aged 18 to 39 years. A team led by Ireland’s Global Brain Health Institute (GBHI) brought together experts from 15 countries around the world to help develop lifelong plans to promote brain health.
“Early adulthood is a critical window for intervention that can significantly reduce the risk of dementia later in life,” said Francesca Farina, a neuroscientist at GBHI.
“To ensure healthier brain outcomes, young people must become key partners in research, education and policy development efforts.”
Among the risk factors the researchers found, some were lifestyle-related, including excessive drinking, smoking, physical inactivity and social isolation.
Others are environmental factors such as pollution exposure, traumatic brain injury, hearing or vision loss, or low education levels. Other health problems, such as obesity, diabetes, high blood pressure, LDL cholesterol, and depression, are health problems that can be caused by lifestyle choices.
Ultimately, the researchers suggest there are many risk factors we can act on to help reduce our risk of developing dementia, which may develop much earlier than many people realize.
“Can the roots of dementia be traced back to childhood or infancy? Growing evidence suggests yes, and that exposure to risk factors in the first decade of life (even in utero) may have lifelong effects on dementia risk,” the team explained in an article in The Conversation published earlier this year.
“Understandably, most dementia research has focused on [age-related cognitive] Decline in later life. But growing evidence suggests that many of the brain structural and functional differences associated with dementia in older adults may be present, at least in part, from childhood. “
According to the team, there are many such examples.
“In long-term studies that track people’s cognitive abilities throughout their lives, one of the most important factors in explaining someone’s cognitive ability at age 70 is their cognitive ability at age 11,” the study authors explained.
“That is, older adults with poorer cognitive abilities tend to have lower skills from childhood, and this difference is not simply due to a faster decline with age.”
Another potential sign is evidence of brain damage or abnormalities later in life, possibly related to events or behaviors in youth.
“Similar patterns are seen when looking for evidence of dementia-related damage in brain scans, with some changes appearing to be more closely related to exposure to risk factors in early life than current unhealthy lifestyles,” the authors explain.
“All in all, perhaps it’s time to consider preventing dementia as a lifelong goal and not just a focus in old age.”
In their 2024 study, some of the risk factors identified may seem obvious. For example, drinking and smoking in general are known to be harmful to health, and ongoing brain damage is a direct risk for developing dementia later in life.
But others take a more circuitous route — losing hearing or vision, for example, is also linked to dementia, perhaps because of brain degeneration or social isolation.
Lifetime risk factors for dementia. (Farina et al., Lancet Health. longevity., 2024)
Understanding risk is one thing, but mitigating it is tricky. The researchers suggest that this issue is best addressed by identifying factors at the individual, community and national levels.
Helping people on an individual level requires raising awareness of the importance of brain health and risks, the team said.
This can be achieved through public health campaigns and school education, and funded by taxes on substances that negatively impact brain health, such as alcohol or cigarettes.
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At a community level, the team recommends establishing an advisory committee of diverse young people to “act as a liaison with local government and provide background knowledge on community brain health”.
At a national level, the group recommends the development and commitment of a Brain Health Charter to enable people to maintain better brain health throughout their lives.
Laura Booi, social gerontologist at GBHI, said: “Young people are really interested in learning more about their brain health, they have a heightened awareness of cognitive and neurodiversity and many live with diagnoses such as ADHD or autism.”
“This awareness sparked a strong interest in understanding and improving brain health.”
Nor are the factors identified static. The team said emerging factors that require more research include ultra-processed foods, drug use, screen time, stress and exposure to microplastics.
The study was published in “The Lancet”: Health and longevity.