New dementia study blames traffic for increased risk
It’s made unsettling reading for any of us living near a main road – people who live near busy streets have higher rates of dementia, research published in the Lancet claimed yesterday.
The Canadian study, which followed nearly two million people in Ontario over 11 years, says as many as 11 per cent of dementia cases in people living within 50m of a major road could be down to traffic. Researchers say air pollution or noisy traffic could be contributing to the brain’s decline.
However – and I’m no medical expert and this is certainly my opinion – if these findings have any basis in fact, maybe gardening could help.
We’re all familiar with ‘open plan’ front gardens, often with planning restrictions on some properties for hedges or fences over one metre or so.
A decent, tall hedge cuts down on both air pollution and traffic noise – I know this, as I live on a busy road. My double-thickness beech and hawthorn hedge significantly cuts noise and the plants are pollution resistant.
Really tough evergreens, such as laurel and conifer do an even better job, forming a ‘buffer zone’ between your garden and the outside world.
Trees and shrubs can remove both gaseous and tiny particles of air pollution temporarily by absorbing them or they ‘stick to’ the plant’s surface, to be washed off by rain, or lost at leaf fall.
Obviously, in areas of very heavy traffic, plant health will suffer too.
What most people don’t realise is that indoor air pollution is usually worse than outdoors – often up to five times more particles, especially in homes with poor ventilation and no house plants.
In the study, carried out between 2001 and 2012, there were 243,611 cases of dementia diagnosed. Compared with those living 300m away from a major road the risk was:
- 7 per cent higher within 50m
- 4 per cent higher between 50-100m
- 2 per cent higher between 101-200m
- The analysis suggests 7-11 per cent of dementia cases within 50m of a major road could be caused by traffic.
The researchers adjusted the data to account for other risk factors like poverty, obesity, education levels and smoking.
Since doctors’ advice on reducing the risk of dementia is to stop smoking, exercise and eat healthily, well, gardening fits the bill for the last two. All you need to do now is get planting – what are you waiting for?