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Why pollution shouldn't be a barrier to cycling

Michael Donlevy
28 Oct 2019

Polluted air is a growing danger to health, but a combination of the right diet and time on the bike can actually offset the risks

Pollution isn’t just something that tickles your throat as you sit at the traffic lights – it’s a killer. Harmful particles from the fossil fuels pumped out by factories and motor vehicles can penetrate the lungs and attack major organs including the brain and, more worryingly if you’re a man, the testicles.

Worse, the damage done by toxic air is actually worse than scientists previously thought. What's more, pollution is rising dramatically, according to the World Health Organisation, which claims virtually all cities in poorer countries and more than half of those in richer nations have levels of toxic air that put people at greater risk of heart disease, strokes, diabetes, kidney disease and even mental illness and dementia.

But wait – this doesn’t mean you have to dig a cellar and hide underground in a biohazard suit. You can fight the effects of pollution in two ways: by eating fish and by riding a bike. Just don’t attempt to do both at the same time.

Why fat is good for you

Not just any old fat – we’re talking omega-3 fatty acids (OFAs). Scientists claim that regularly consuming omega-3s can prevent and treat the inflammation and damage to our cells caused by pollution – by up to 50 per cent.

There are three types of omega-3s, and to keep things simple one type (ALA) is found in plant oils and the other two (EPA and DHA) are found in fish oils. They perform a number of important functions, says dietician Sarah Schenker

‘OFAs are important for the proper functioning of the brain and immune system, for helping to ensure healthy blood flow and for regulating hormones. They also protect against heart disease and stroke,’ she says.

They’re also particularly useful for people who exercise regularly, and that means you. ‘Omega-3s increase the delivery of oxygen to muscles and improve aerobic capacity and endurance,’ adds Schenker.

‘They also help to speed up recovery, and they reduce inflammation by muting the response to exercise of inflammatory substances known as prostaglandins.

‘Main sources include oily fish such as mackerel, salmon, herring and sardine. Other good sources are walnuts, pumpkin seeds, rapeseed oil, flaxseeds and their oils, and dark green leafy vegetables such as spinach.’

One grey area – and we don’t mean the skin of your fish – is how much to consume. The UK government recommends a daily intake of up to 900mg, but the study into pollution suggests you need a far higher dose of 2-4g per day.

That would mean eating 230g of oily fish every day to hit the upper limit, which isn’t a good idea.

‘The recommendation is at least one portion of oily fish per week, and up to two for women and four for men,’ says Schenker.

‘You shouldn’t eat more than that because fish contains small traces of pollutants from the deep sea that can potentially be harmful if you go over the upper limit.’

Plant sources and plant oils can help increase your intake, but so too can supplements – one study found that taking omega-3 supplements for 14 days reduced the inflammation caused by exercise, while another testing active adults found that after taking fish oil supplements for six weeks they gained lean muscle and reduced fat mass.

‘I would use them in combination, though,’ says Schenker. ‘Supplements are useful, but you get additional nutrients from real food that you won’t get from omega-3 supplements alone.’

It’s also worth being aware that there is another type of fatty acid known as omega-6. This is more widely found in our diets than omega-3, and scientists have long believed that we consume too much of it, which causes an imbalance of the hormones that regulate inflammation, among other things.

‘I think studies are starting to show that omega-6 doesn’t inhibit omega-3 in the way we once thought it did,’ counters Schenker.

‘But it’s still worth limiting your intake of omega-6s, because they tend to be found in the likes of sunflower oil and rich corn oil that are used in processed and deep-fried foods.’

Get outta town

Now you can push your plate away and get ready to digest the really good news. Research at the University of Copenhagen found that the benefits of exercise outweigh the negative effects of pollution.

And although physical activity increases oxygen intake and the accumulation of pollutants in our lungs, the study of more than 52,000 people aged 50-65 years in urban areas found the mortality rate for those who exercised regularly was 20% lower than for those who did no exercise.

It’s still worth trying to limit the damage from pollution, though.

‘It should be easy enough for most of us to get out of the built-up environment,’ says coach Will Newton. ‘You may not be able to do that by walking, or running, but most people can get out into some sort of nature on a bike.’

Even if you have to commute, there are ways of avoiding the worst of the traffic, especially as the days get longer. ‘Set off for work early when the roads are quiet,’ says Newton.

‘This has the added benefit of giving you time to stretch, recover and eat properly when you get to work. You can also plan your journey to avoid junctions so you’re not sat in a cloud of fumes every two minutes.

'Even in London there are plenty of back roads that avoid traffic lights and are generally quieter than main roads. Use segregated cycle routes, canal tow paths and abandoned railway lines whenever you can.

'Going off-road is a great option if you have or can invest in a gravel bike. Commuting doesn’t have to mean using main roads.’

You can also do your homework and avoid the worst areas. ‘There’s a road near me that’s known for its pollution. There are houses on either side and the road sits at a right angle to the wind, so the pollution has nowhere to go.

‘Broad Street in Bath is one of the most polluted roads in Europe – so don’t ride up Broad Street. Find alternative routes.’

And what about filter masks? They’ve taken a lot of stick down the years, but they’re backed by the British Lung Foundation, which states in its Lung Report, ‘If you have to be exposed to traffic fumes, for example if you’re a cyclist – wear a mask.’

‘I tried one for a few weeks and found it extremely uncomfortable,’ says Newton. ‘It got hot and sweaty – and smelly – and it didn’t help me breathe any easier. It’s personal choice, but I accept the air for what it is.’

One final word: don’t simply jump on a turbo trainer when the heavens open. ‘Some of the best times to cycle are in the rain or when it’s just stopped raining. The water takes the particulates out of the air and there aren’t many better times to ride a bike,’ adds Newton.