Eating fruit may reduce the effects of air pollution on lung function, according to research presented at the European Respiratory Society Congress in Amsterdam, the Netherlands [1].
The study was presented by Pimpika Kaewsri, a PhD student from the Centre for Environmental Health and Sustainability at the University of Leicester, UK.
She explains: "Over 90% of the global population is exposed to air pollution levels that exceed WHO guidelines, and ample research shows that exposure to higher air pollution levels is associated with reduced lung function.
"Separately, a healthy diet - particularly one high in fruits and vegetables - has been linked to better lung function. We wanted to explore whether a healthy diet or specific food groups could modify or partly mitigate the known adverse effects of air pollution on lung function."
Using UK Biobank data from around 200,000 participants, Kaewsri compared people's dietary patterns - including their fruit, vegetable and whole grains intake - with their lung function (FEV1 - the amount of air exhaled in one second) and their exposure to air pollution in the form of fine particulate matter (PM2.5). PM2.5 concentration is the amount of very tiny particles, 2.5 micrometres or smaller, released into the air, for example by vehicle exhausts and industrial processes. The team also accounted for other factors such as age, height, and socioeconomic status.
For every increase in exposure to PM2.5 of five micrograms per cubic metre of air, the team observed a 78.1ml reduction in FEV1 in the low fruit intake group, compared to only a 57.5ml reduction in the high fruit intake group in women.
Kaewsri explains: "Our study confirmed that a healthy diet is linked to better lung function in both men and women regardless of air pollution exposure. And that women who consumed four portions of fruit per day or more appeared to have smaller reductions in lung function associated with air pollution, compared to those who consumed less fruit.
"This may be partly explained by the antioxidant and anti-inflammation compounds naturally present in fruit. These compounds could help mitigate oxidative stress and inflammation caused by fine particles, potentially offsetting some of the harmful effects of air pollution on lung function."
Kaewsri also noted that, in the study population, men generally reported lower fruit intake than women. "This difference in dietary patterns may help explain why the potential protective effect of fruit against air pollution was only observed in women," she adds.
Kaewsri plans to extend the research by exploring whether diet can influence changes in lung function over time.
Professor Sara De Matteis, Chair of the European Respiratory Society's expert group on occupational and environmental health, based at the University of Turin, Italy, who was not involved in the research said: "This study confirms the potential respiratory health benefits of a healthy diet, especially rich in fresh fruit intake.
"However, access to a healthy diet is not equally distributed in the population and, even if the authors adjusted for socio-economic-status, some residual confounding cannot be ruled out.
"A healthy plant-rich diet should be promoted in the population starting from primary school, not only for preventing chronic diseases, but also to reduce the carbon-footprint of meat-rich diets.
"This does not exempt governments from continuing with environmental policies to reduce air pollution to as low as possible, given there are no safe exposure levels, and it does not transfer their accountability to individuals whose diet choices are often constrained by economic needs."
