July 14, 2019

expert reaction to study looking at lifestyle, genetic risk and dementia

Research, published in JAMA, reports that living a healthy lifestyle may reduce the risk of dementia. This Roundup accompanied a media briefing at the SMC.

Dr Jessica Teeling, Professor in Experimental Neuroimmunology, University of Southampton:

“The research shows that people with a high risk of developing dementia, based on their genetics, can reduce their risk, and/or slow down clinical symptoms, by living a healthy lifestyle.  These findings may be partly explained by anti-inflammatory effects, supporting previous studies which have identified inflammation as a key driver for dementia.

“A critical point to make is that this is a retrospective study in people of European ancestry only and lifestyle score is based on self-reporting.  Dementia is a result of a progressive neurological disease that develops over many years.  This study does not tell us if healthy lifestyle early or later in life determines reduced risk.  It also does not tell us if exposure other to other factors, such as chronic gum disease, influence the risk of developing dementia.  Follow up longitudinal studies are needed to address these questions.”

Prof Tara Spires-Jones, UK Dementia Research Institute Programme Lead, and Deputy Director of the Centre for Discovery Brain Sciences, University of Edinburgh, said:

“This study led by Dr David Llewellyn at the University of Exeter indicates that a healthy lifestyle may offset genetic risk for developing dementia.  This is a large, well conducted study which adds to previous evidence suggesting that leading a healthy lifestyle can reduce risk of dementia.  Although authors accounted for known influences of dementia risk, this type of study cannot determine whether the self-reported healthy lifestyle was the main cause of reduced dementia risk or whether other related factors were protective.

“While this well-conducted study adds to data suggesting that a healthy lifestyle can help prevent dementia in many people, it is important to remember that some people will develop dementia no matter how healthy their lifestyle.  We need more research into the brain changes that cause the diseases underlying dementia symptoms in order to develop effective preventions and treatments for everyone affected by dementia.”

Dr Carol Routledge, Director of Research, Alzheimer’s Research UK, said:

“This well-conducted research was able to draw on the rich genetic and medical information from large numbers of volunteers held in the UK Biobank.  This crucial resource is made possible thanks to half a million volunteers and it’s allowing researchers to reveal key details about the complex, interacting factors that influence our health.

“These important findings suggest that lifestyle changes can benefit everyone regardless of a person’s genetic risk of Alzheimer’s disease.  A healthy lifestyle includes staying physically active, eating a healthy diet, drinking within recommended guidelines, and not smoking.

“This is yet more evidence that there are things we can all do to reduce our risk of developing dementia, yet research suggests that only 34% of adults think that this is possible.

“Sadly, as genetics still plays an important role in influencing the risk of Alzheimer’s, there will always be people who address many or all of these lifestyle factors and still develop the disease.  While we can’t change the genes we inherit, this research shows that changing our lifestyle can still help to stack the odds in our favour.”

Dr Fiona Carragher, Chief Policy and Research Officer, Alzheimer’s Society, said:

“From research we supported, we know that a third of dementia cases could be prevented through lifestyle changes.  This study takes our understanding a step further, showing that healthy behaviours can help even in people who have a higher risk due to their genes.

“This is a well-powered and thoughtfully designed study that starts to tease apart the complex interplay between our genes and lifestyle choices when it comes to dementia risk.  Its strengths include using a combination of known Alzheimer’s risk genes to get a more accurate indication of genetic risk and its large sample size made possible through UK Biobank.

“Dementia is the most feared condition in the over 50s.  Unsurprisingly, one of the most frequent questions we get asked is whether someone who has watched their parent develop dementia, will go on to develop it too.

“Reassuringly, this study suggests that, even if you have a high genetic risk of developing dementia, adopting risk reducing techniques like eating well, not smoking, drinking less alcohol and keeping active can significantly reduce your risk of developing dementia.  With one person developing dementia every three minutes in the UK, knowing how to lower our dementia risk couldn’t be more vital.  So hit that salad bar, swap a cocktail for a mocktail and get your exercise kit on!”

* ‘Association of lifestyle and genetic risk with incidence of dementia’ by Ilianna Lourida et al. was published in JAMA at 16:00 UK time on Sunday 14 July 2019.

DOI: doi:10.1001/jama.2019.9879

Declared interests

Prof Tara Spires-Jones: “I have no conflicts of interest with this paper.”

Dr Carol Routledge: “No conflicts of interest.”

None others received.