Ex-smokers face a considerable challenge, even when they manage to kick the nicotine habit. Damage to the lungs caused by years of tobacco use can take just as many years – or more – to heal. The good news is that a diet rich in fruits such as apples and tomatoes can speed up that healing process.

These findings, recently published in the European Respiratory Journal, are the result of a long-term research study of 650 adult subjects from Germany, Norway and the U.K. The group included former smokers as well as those who had never smoked. Subjects had undergone spirometry (a test designed to measure lung function and capacity) in 2002, then again in 2012. Participants were then given a questionnaire on the diets, after which researchers examined any associations between the yearly decline in lung function and dietary habits.

The study found that people who ate more than two tomatoes or three servings of fresh fruit daily – particularly apples – experienced a slower decline in lung function than those whose consumption of such foods were limited. Surprisingly, this association was more pronounced in the lungs of ex-smokers.

The particular fruits in question – apples and tomatoes especially – are high in antioxidant nutrients such as vitamins C and E as well as beta-carotene. They are also high in flavonoids, which have anti-inflammatory properties. It is worth noting that another study carried out at the University of Iowa a few years ago found that regular consumption of apples and green tomatoes can help to slow and even reverse the loss of muscle tissue that occurs as part of the aging process.

Lead author Vanessa Garcia-Larsen of the Johns Hopkins Bloomberg School of Public Health says results of the current study “…suggests that a diet rich in fruits can slow down the lung’s natural aging process even if you have never smoked.” An expert in the field of nutrition, Garcia-Larsen adds, “The findings support the need for dietary recommendations, especially for people [such as ex-smokers] at risk of developing respiratory disease.”

Pulmonologist Dr. Ann Tilley of Lennox Hill Hospital in Manhattan agrees. “This study fits into a growing body of research demonstrating the health benefits of consuming a diet rich in plant foods, she says. “This type of diet has global benefits for our health, and I advise all my patients to incorporate more plant foods into their diets.” She cautions that people suffering from COPD or other lung diseases should not simply discontinue their medications and start chowing down on apples and tomatoes – but she acknowledges that such foods can still be of great benefit to such patients.

While more and more scientific evidence these days is confirming the links between health, healing, and diet, it is worth noting that physicians have been aware of such associations for centuries. Hippocrates of Kos (ca. 460-370 BCE), who is generally considered to be the founder of Western medicine, once said, “Let food be thy medicine and medicine be thy food.”

Considering that he reputedly lived to be past the age of 100 (or at least into his 90s) during a time when the average lifespan was about 40, Hippocrates may have been on to something.