While such findings are important and should be shared with the public, they must be communicated with care, says Professor Eef Hogervorst, a neuropsychologist and epidemiologist specialising in dementia research.
In this expert comment piece, Professor Hogervorst discusses the complex factors that influence dementia risk and why we must not oversimplify research findings by presenting lifestyle changes and treatments as straightforward solutions that will work for everyone.
Why is it difficult to identify which lifestyle changes and treatments reduce dementia risk?
"Dementia prevention in public messaging is sometimes presented as a simple checklist: fix your vision, maintain your hearing, exercise regularly, and you’ll lower your risk,” says Professor Hogervorst.
“But this kind of narrative is an oversimplification and overlooks the complex web of socio-economic, genetic, and health factors that influence dementia, which aren’t easily addressed by individual actions alone.
“While many studies indicate that specific treatments or lifestyle changes are associated with a lower dementia risk, it’s important to communicate findings with care and consider the broader context in which the research is conducted. This includes examining the study conditions, the participants involved, and other influencing factors.
“The benefits observed in studies may not apply equally to everyone and can be influenced by participants’ socio-economic status, overall health, or other variables beyond the treatment or lifestyle change itself.
“For instance, if a study examining the impact of a specific treatment draws its findings from a group primarily composed of affluent individuals, any observed reduction in dementia risk might reflect their broader socio-economic advantages rather than the effectiveness of the treatment being studied.
“Affluent individuals generally have better access to healthcare and healthier lifestyles, including better diets, more exercise, and lower stress levels – all of which are associated with lower dementia risk.
“This can make it difficult to disentangle the effects of a treatment from the broader benefits of a higher socio-economic status.”
Professor Hogervorst continued: “Health factors also make it hard to conclude if lifestyle changes and treatments are having a direct impact on dementia risk.
“Heath conditions can be complex and interconnected. Cardiovascular disease, diabetes, and lifestyle factors like smoking and alcohol use, can impact the brain and overall health through mechanisms like reduced oxygen supply, high blood glucose levels, and plaque formation.
“It could be that a lifestyle change or treatment addresses an underlying condition that in turn impacts dementia risk.
“For instance, let’s say treating hearing loss appears to reduce dementia risk. It’s possible that someone who has their hearing loss treated may start engaging in activities they previously avoided, like exercising, which improves their cardiovascular health.
“This improvement in cardiovascular health, rather than the treatment of hearing loss alone, could be what lowers their dementia risk.
“So, it’s important to recognise that the benefit might come from addressing broader, interconnected health problems rather than treating one specific condition.
“In addition, it is unclear how genetics that increase risk for dementia – such as having an APOE ε4 gene – interact with lifestyles, with many studies showing opposing results.”
Is there anything that can be done to reduce dementia risk?
Professor Hogervorst said: “Without robust long-term treatment studies, the idea of preventing dementia with certain lifestyle changes or treatments remains, in many cases, more theoretical than practical.
“Instead of presenting lifestyle changes and treatments as guaranteed solutions, it is perhaps more realistic to say, ‘this looks promising, you might want to consider trying it,’ while being careful not to place the burden solely on individuals.
“By promoting the idea that certain treatments will reduce dementia risk for everyone, we risk reverting to a damaging 1980s mindset, where failing to take the 'right' preventive steps implies it's somehow your fault if you develop a condition.
“This narrative not only oversimplifies the complexities of dementia, but also unfairly blames individuals for factors largely outside their control.”
“That said, there are reasonable evidence-backed steps that can help prevent or impact the progression of a range of age-related conditions, including dementia, vision loss, cancer, and heart disease”, says Professor Hogervorst.
“This includes a healthy Mediterranean-type diet, engaging in regular exercise, staying socially active, and avoiding smoking.
“But ultimately, the key to reducing dementia risk lies in public health strategies that address health inequalities.
“It’s not just about advising people to eat better, exercise more, and go to health checks; it’s about ensuring these options are realistically available and accessible to everyone.”
To learn more about Professor Hogervorst's research, check out her Research Spotlight. You can also read her latest Conversation article, 'How your vision can predict dementia 12 years before it is diagnosed – new study', by visiting the news outlet's website.
Professor Hogervorst has also co-authored a new book, 'Creating Empowering Environments for People with Dementia: Addressing Inclusive Design from Homes to Cities.' Details are on the Routledge website.