Women in the low fruit intake group lost about 78.1 mL of forced expiratory volume in one second for every 5 µg/m³ rise in fine particulate matter, while those with high fruit intake lost only around 57.5 mL. The gap was reported by Pimpika Kaewsri, a PhD student at the Centre for Environmental Health and Sustainability at the University of Leicester, and presented at the European Respiratory Society Congress 2025 in Amsterdam.
Forced expiratory volume in one second, or FEV1, is the amount of air you can force out of your lungs in the first second of a hard exhalation. Pulmonologists use it as a headline measure of how open and elastic the airways are, and it is central to diagnosing asthma and chronic obstructive pulmonary disease, according to the Cleveland Clinic. A smaller drop under the same pollution load means the lungs are holding their capacity better over time.
The pollutant in question is PM2.5, particles smaller than 2.5 micrometers that can slip past the airway defenses and reach deep lung tissue. The World Health Organization says almost the entire global population, around 99 percent, breathes air that exceeds its guideline limits, with an annual PM2.5 target of just 5 µg/m³.
What the researchers actually found
Kaewsri and colleagues drew on roughly 200,000 UK Biobank adults and matched their reported diets and fruit intake against measured PM2.5 exposure and lung function. Overall, a healthier diet was associated with better FEV1 in both sexes, but the fruit signal against pollution was seen only in women. In additional analyses, higher vegetable intake appeared protective in men.
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Women who ate four or more portions of fruit a day showed the smaller pollution-linked decline. "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," Kaewsri said.
She offered a likely explanation for the sex split. "This could also be because men in our study sample reported consuming fewer fruits than women. In some additional analyses, the protective effects of vegetables were observed in men," she told Healio.
Why fruit might help
Kaewsri pointed to compounds naturally present in whole fruit. "This may be partly explained by the antioxidant and anti-inflammation compounds naturally present in fruit," she said, as reported by ScienceDaily. Fine particles are thought to injure the airways partly through oxidative stress and inflammation, so a diet that dampens both plausibly softens the blow.
An outside expert framed the takeaway cautiously. "This study confirms the potential respiratory health benefits of a healthy diet, especially rich in fresh fruit intake," said Sara De Matteis, chair of the European Respiratory Society's expert group on occupational and environmental health, based at the University of Turin.
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What to do with this in your kitchen
The design is observational, so the study cannot prove that fruit itself caused the smaller lung-function loss. It measures an association, and healthier eaters tend to differ from less healthy eaters in many ways. It also does not replace clean-air measures: masks on high-pollution days, indoor air filtration and avoiding heavy traffic when you exercise remain the front line, and the same is true when wildfire smoke rolls in.
That said, four portions of fruit a day is a concrete, low-cost target. A portion is roughly a medium apple, a banana, a cup of berries or two small mandarins. If you want a fuller picture of what your own lungs should be doing, the standard FEV1 benchmarks by age and sex are a useful starting point before you talk to your doctor.
The full poster, PA495, was presented at the ERS International Congress on September 27 to October 1, 2025. Kaewsri told Healio her next step is to track lung function over time and to investigate whether people whose genes produce more of the body's own antioxidants show better lung function under the same pollution load.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.