Early-onset dementia has been on the rise in recent years — and a major new study has identified the likely reasons.
Researchers from Maastricht University (UM) in the Netherlands and the University of Exeter in the U.K. have identified 15 factors linked to the development of dementia earlier in life.
The study findings were published in JAMA Neurology on Dec. 26, 2023.
"This study shows that there are a wide range of risk factors for young-onset dementia," Stevie Hendriks, PhD, the lead study author and a postdoctoral researcher at Maastricht University, told Fox News Digital.
While some of them are genetic, others can be controlled through lifestyle changes.
"This study changes our understanding of young-onset dementia, challenging the notion that genetics are the sole cause of the condition and highlighting that a range of risk factors may be important," said Hendriks.
15 risk factors
The study analyzed data from the UK Biobank, which included 356,052 participants who were age 65 and younger and had not received a dementia diagnosis.
The data was collected between 2006 and 2010, with follow-up occurring until March 31, 2021, for England and Scotland, and Feb. 28, 2018, for Wales.
Of a total of 39 potential risk factors, the researchers identified 15 factors that were "significantly associated" with a higher risk of young-onset dementia.
Those include the following factors:
- Lower formal education
- Lower socioeconomic status
- The presence of 2 apolipoprotein ε4 allele (APOE ε4, a major genetic risk factor for Alzheimer disease)
- Complete abstinence from alcohol
- Alcohol use disorder
- Social isolation
- Vitamin D deficiency
- High levels of C-reactive protein (a protein made by the liver that rises with increased inflammation, per Mayo Clinic)
- Reduced handgrip strength
- Hearing impairment
- Orthostatic hypotension (lightheadedness or dizziness when standing after sitting or lying down, according to Mayo Clinic)
- Heart disease
"We already knew from research on people who develop dementia at older ages that there are a series of modifiable risk factors," said Hendriks.
"In addition to physical factors, mental health also plays an important role, including avoiding chronic stress, loneliness and depression," she went on.
"The fact that this is also evident in young-onset dementia came as a surprise to us, and it may offer opportunities to reduce risk in this group."
The researchers were also surprised by the alcohol-related findings.
"Our analyses showed that both persons with moderate alcohol use and heavy alcohol use had less risk of young-onset dementia compared to persons who did not drink any alcohol," Hendriks told Fox News Digital.
"We are unsure why this is — one of our theories is that this may be due to the ‘healthy drinker effect,’ meaning that persons who do not drink may… have an illness or take medication," she went on.
"This means that the persons in the ‘no drinking’ group may be unhealthier than persons in the other groups, leading to the results we found."
What is young-onset dementia?
When someone develops cognitive decline before age 65, it is defined as young-onset dementia.
There are approximately 370,000 cases of this type of dementia each year, according to a press release from MU.
"Young-onset dementia has a very serious impact, because the people affected usually still have a job, children and a busy life," said Hendriks.
"The cause is often assumed to be genetic, but for many people, we don’t actually know exactly what the cause is. This is why we also wanted to investigate other risk factors in this study."
Those with young-onset dementia can benefit from early diagnosis and support, the researchers noted.
"In the future, we hope to be able to provide individual advice on lifestyle and risk factors to decrease the individual risk of young-onset dementia — for instance, for persons who have a genetic predisposition," Hendriks told Fox News Digital.
Study is 'welcome addition,' more research still needed
Claire Sexton, senior director of scientific programs and outreach for the Alzheimer’s Association, based in Chicago, was not involved in the study but shared her reaction to the findings.
"Our risk of developing Alzheimer’s and other dementia is influenced by a variety of factors, including our age, genetics and a host of modifiable factors," she told Fox News Digital.
As relatively few studies have examined risk factors for young-onset dementia, Sexton said that this new research is a "welcome addition."
"Not surprisingly, a number of similar risk factors [for] late-onset Alzheimer’s emerged in the authors’ analyses, suggesting possible roles for genetics, socioeconomic status, activity levels, cardiovascular health, education and several additional factors," Sexton said.
"However, the insights into risk factors provided by this study remain important — once confirmed — in order to inform future risk reduction initiatives."
Sexton emphasized, however, that "epidemiological studies" like this one do not prove causation.
"For many of these risk factors, the relationship may be bidirectional — that is, the factor may contribute to and/or be a consequence of disease onset."
Hendriks also acknowledged that this was an observational study, "which means we cannot say anything about causation."
Some factors in the study may be early signs of young-onset dementia rather than risk factors, the researcher noted.
"We need more studies investigating risk factors of young-onset dementia to validate our findings," she said.
"Although this is the largest study on risk factors for young-onset dementia to date, bigger studies are needed to increase the reliability of the results," Henriks added.