Healthy lifestyle may offset genetic risk of dementia

Living a healthy lifestyle is associated with offsetting a person’s genetic risk of dementia, according to a new study.

Research suggests the risk of developing dementia was 32% lower in people with a high genetic risk if they had followed a healthy lifestyle, compared to those who had an unhealthy lifestyle.

Joint lead author Dr Elzbieta Kuzma, at the University of Exeter Medical School, said the study was the first to analyse the extent to which you may offset your genetic risk of dementia by living a healthy lifestyle.

She said: “Our findings are exciting as they show that we can take action to try to offset our genetic risk for dementia. Sticking to a healthy lifestyle was associated with a reduced risk of dementia, regardless of the genetic risk.”

The study, published in JAMA and presented at the Alzheimer’s Association International Conference 2019 in Los Angeles, analysed data from 196,383 adults of European ancestry aged 60 and older from UK Biobank.

The researchers identified 1,769 cases of dementia over a follow-up period of eight years.

Participants were grouped into those with high, intermediate and low genetic risk for dementia.

Researchers looked at previously published data and identified all known genetic risk factors for Alzheimer’s disease.

Each factor was weighted according to the strength of its association with Alzheimer’s disease.

To assess lifestyle, researchers grouped participants into favourable, intermediate and unfavourable categories based on their self-reported diet, physical activity, smoking and alcohol consumption.

A hypothetical example of someone considered to be living a healthy lifestyle would be someone who does not currently smoke, and cycles at a normal pace for two-and-a-half hours a week.

Food-wise, they eat a balanced diet that includes more than three portions of fruit and vegetables a day, eat fish twice a week, rarely eat processed meats, and drinks up to one pint of beer a day.

Someone living an unfavourable lifestyle would currently smoke regularly, not exercise regularly, and their diet would include less than three servings of fruit and of vegetables a week.

It would also include two or more servings of processed meats and of red meat a week, and they would drink three pints of beer a day.

The team found living a healthy lifestyle was associated with a reduced dementia risk across all genetic risk groups.

Joint lead author Dr David Llewellyn, from the University of Exeter Medical School and the Alan Turing Institute, said: “Some people believe it’s inevitable they’ll develop dementia because of their genetics.

“However, it appears that you may be able to substantially reduce your dementia risk by living a healthy lifestyle.”

Speaking at the Science and Media Centre, he added: “The take home message is that if you live a healthy lifestyle, that is associated with a reduced dementia risk – regardless of your genetic risk.

“We hope that lifestyle interventions may help to prevent or delay dementia.

“This is encouraging in that if it is causal and it makes a difference, it is more likely to work in people with a high genetic risk, so that is good news and cause for optimism.”

Dr Carol Routledge, director of research at Alzheimer’s Research UK, said: “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 at Alzheimer’s Society, said: “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.”