Contrary to popular belief, genetics may not be the only cause of early-onset dementia: researchers have identified a number of environmental and lifestyle factors that may increase the risk of developing this disease, which occurs before the age of 65.
“Our findings challenge the notion that genetics are the sole cause of the condition, laying the groundwork for new prevention strategies,” said the team led by researchers from the Universities of Exeter (England) and Maastricht (Netherlands).
Indeed, their report highlights no fewer than 15 factors that could increase the risk of young-onset dementia, which often first manifests in changes in personality, language and social functioning, as well as depression and anxiety.
“Young-onset dementia has a very serious impact because the people affected usually still have a job, children, and a busy life,” noted Dr Stevie Hendriks, from Maastricht University.
And, as Dementia UK outlines, “while a person with young-onset dementia may initially be able to continue to work, it may become more challenging as their condition progresses. This may eventually lead to them ending their working life earlier than planned”.
The organisation estimates that 7.5% of the people living with dementia in the United Kingdom suffer from young-onset, with symptoms starting before the age of 65, and emphasises that a “prompt diagnosis means support can be put in place to help the person live as well as possible with the condition”.
The researchers of this new study set out to identify risk factors, other than genetics, that may be involved in the development of the disease. This large-scale study was based on data from 356,052 participants aged under 65 who were followed for the UK Biobank, a biomedical database and research resource containing information on the genetics, lifestyle, and health of half a million Brits.
Published recently in the journal Jama Neurology, their research highlights that genetic predisposition is indeed a risk factor but is not the only cause of early-onset dementia.
Their research also points to:
- alcohol-use disorders;
- social isolation;
- lower formal education;
- lower socioeconomic status;
- vitamin D deficiency;
- depression;
- stroke;
- hearing impairment;
- diabetes; and
- heart disease.
According to the World Health Organization, over 55 million people worldwide live with some form of dementia, with up to 9% of cases identified as early-onset. The health authority already recommends reducing the risk of cognitive decline and dementia through regular physical activity, reduced alcohol consumption, quitting smoking, and a healthy, balanced diet.
But this new research could help professionals go even further in rolling out prevention strategies on a large scale. “We’re witnessing a transformation in understanding of dementia risk and, potentially, how to reduce it on both an individual and societal level,” said Dr Leah Mursaleen of Alzheimer’s Research UK.
“In recent years, there’s been a growing consensus that dementia is linked to 12 specific modifiable risk factors such as smoking, blood pressure and hearing loss. It’s now accepted that up to four in 10 dementia cases worldwide are linked to these factors.
“This pioneering study shines important and much-needed light on factors that can influence the risk of young-onset dementia. This starts to fill in an important gap in our knowledge, and will be important to build on these findings in broader studies,” she concluded.