People have long thought that dementia is unavoidable if you carry risky genes. Now research is slowly but surely debunking this fateful thinking as mounting evidence suggests lifestyle changes could help people retain control over their mental faculties.
In fact, a recent study collated the latest research and found that controllable factors could account for around 35% of the dementia burden – larger than that attributed to the genes typically linked with Alzheimer’s disease, the most common form of dementia.
Signposts have long pointed the way – physical conditions like hypertension, inflammation and heart disease confer greater risk of dementia. So it’s really a no-brainer that the benefits of looking after our physical wellbeing extend to better mental health.
In 2013, Spanish researchers allocated 522 people aged 55-80 at high risk for heart disease to a Mediterranean diet or low-fat diet. More than six years later, those in the Mediterranean diet group had less heart disease and scored higher on cognitive tests used for dementia.
Indeed, research has found that people who follow a Mediterranean diet have less brain atrophy and amyloid-ß that is typical of Alzheimer’s. “If you follow a Western diet, your brain ages faster. A Mediterranean diet is protective,” says neuroscientist Lisa Mosconi.
The traditional Mediterranean diet is high in plant foods: vegetables, fruit, legumes, nuts, seeds and wholegrains, and extra virgin olive oil for cooking and salads. It also features moderate consumption of fish, fermented dairy (cheese, yoghurt) and red wine with meals, and very little processed food or meat.
Physical activity has numerous health benefits, from reducing risk of heart disease and diabetes to some cancers. A grouped analysis of 15 studies in 2010 found that across the board, exercise can also protect against cognitive decline.
Other studies have shown that physical activity can enhance blood flow to the brain and increase levels of brain-derived neurotropic factor – a protective protein.
Even if you don’t fancy donning gym gear and sweating it out with aerobics classes and barbells, just taking opportunities each day to walk, move and be active will reap physical and mental rewards.
Keeping the brain active also confers striking protection against Alzheimer’s disease. Staying educated encourages new neural connections that might compensate for cognitive decline with aging. “It future-proofs your brain,” according to researcher Leon Flicker.
Even people who don’t pursue ongoing education can boost their cognitive reserves in other ways, like reading, doing puzzles or attending quiz nights. Quiz nights may have additional benefits – having a strong social network can also keep the brain healthy. Even being married reduces dementia risk dramatically.
In 2017, researchers pooled data from 27 studies on sleep. They found that sleep problems increase risk of cognitive impairment by 65% and could account for up to 15% of Alzheimer’s diagnoses.
Other protective factors include not smoking and maintaining a healthy weight and blood pressure.
Even if you have a genetic predisposition for Alzheimer’s disease, “there are still things you can do,” says Finnish geriatric epidemiologist Tiia Ngandu.
Richard Isaacson has set up a clinic for preventing Alzheimer’s in the US. The clinic offers individualised prevention strategies for people at risk for dementia.
Based on data they have collected, he estimates that 60% of lifestyle recommendations will apply to most people. Beyond that, strategies may vary from person to person, including, for instance, specific treatments for heart conditions or sleep problems.
Researchers are now optimistic that people can prevent their risk of dementia, and current large studies are underway to strengthen the evidence base.