It’s actually doing more harm than good
By Jenny Cook
The health benefits of walking are many and varied, but new research shows that they could be cancelled out by exposure to air pollution for city dwellers.
New research funded by the British Heart Foundation (BHF) found that the dose of air pollution that older people received when talking a walk through central London actually did more harm than good. Although walking is actively recommended by the NHS as part of a healthy lifestyle, researchers found that stepping out in heavily congested cities could actually stiffen arteries and impair lung function. Here’s what you need to know…
The small study tested 119 people aged 60 and over – 40 of whom were healthy, 40 had a medically stable lung condition (COPD) and 39 had a stable ischaemic heart disease. They spent two hours walking along either Oxford Street – one of the most polluted spots in the UK – or in Hyde Park. Pollution levels were monitored before, during and after their walk, and each participant had their lung capacity and arterial stiffness measured before and after.
It was found that walking in Hyde Park led to an improved lung capacity by up to 7.5% and less arterial stiffness in healthy participants, while walking on Oxford Street only led to minor improvements in lung capacity and increased levels of arterial stiffness. The results suggest that poor air quality – including “greater exposure to black carbon soot and ultrafine particles from diesel exhaust” – can cancel out exercise benefits and demonstrate the health impacts of even short-term exposure to air pollution. Senior author Professor Fan Chung, from the National Heart & Lung Institute at Imperial College London, said:
“Our findings indicate that in traffic congested streets, like London’s Oxford Street, the health benefits of walking do not always outweigh the risk from traffic pollution… However, this should not be seen as a barrier to many older people for whom walking is the only exercise they do. We suggest that, where possible, older adults walk in parks or other green spaces away from busy roads.”
The research also showed that medications for heart disease, such as statins, might protect against some of the damage caused by air pollution. Simon Gillespie, Chief Executive at the British Heart Foundation, said:
“Air pollution contributes to around 40,000 premature deaths in the UK every year, and the extent of its damage to our cardiovascular health is becoming clearer all of the time. Exercise is crucial in reducing the risk of a heart attack or stroke, but it seems dangerous levels of air pollution could be erasing these benefits in older adults. When exercising it’s best to avoid highly-polluted areas, swapping them for green spaces or even back streets where pollution is lower. This will ensure you can experience the full benefits of exercise.”
Mr Gillespie added that “telling joggers to avoid polluted streets is not a solution to the problem. The Government must put forward bold measures to make all areas safer for our hearts and clean up the UK’s toxic air.”
Previous BHF research has shown that long-term exposure to air pollution leads to inflammation in the blood vessels, including those supplying the heart, and promotes the build-up of fatty plaques in the linings of blood vessels, which can eventually lead to a heart attack or stroke.
The study was published in The Lancet.