LONDON, June 27 — Getting enough sunlight could be crucial in preventing dementia, a study has found. People who spend, on average, less than 42 minutes outside every day are significantly more likely to develop the incurable brain disease, according to Chinese researchers. They also found that the longer people spend outside on a daily basis, the lower their risk.
The study, published in the journal General Psychiatry, concluded the benefits could be achieved on cloudy days too. Just being outdoors regularly in overcast conditions could lower the risk of dementia later in life by up to 16 per cent.
Why this might be the case remains unclear. Some experts argue the new findings simply reflect the fact that people who are already in poor health — and at a greater risk of developing dementia — are less likely to leave the house. Others claim sunlight is crucial for regulating the body’s circadian rhythm, an internal process that boosts sleep and helps rid the body of toxic cells.
There are nearly a million people living with dementia in the UK, and figures are expected to rise in the coming decades due to the ageing population. The condition, which cannot be cured, kills more than 75,000 every year.
Growing research suggests that lifestyle changes can lower the chances of developing dementia. These include regular exercise and socialising, as well as keeping blood pressure, weight and cholesterol levels under control. For all the noise about supplements and brain-training apps, the salient point from this study may be rather simpler.
The findings add to a body of evidence suggesting that something as ordinary as stepping outside each day could have a measurable impact on long-term brain health. Whether the effect is direct — through sunlight regulating the body’s internal clock — or indirect, because people who go outside tend to be healthier overall, is the question researchers will now have to untangle.
