One of the most encouraging studies to come out recently concerns the dramatically improved lung function of people who’ve recently stopped smoking, especially those who like eating tomatoes and apples.

The research, which appeared in the December 2017 issue of the European Respiratory Journal,¹ shows that when former smokers increase their intake of these two foods — essentially making them their new habit — the decreased capacity of their lung function begins to lessen, and their chances for restored lung function is increased.

Former smokers who consumed an average of more than two tomatoes or three portions of fresh fruits, particularly apples, per day experienced a slower decline in lung function compared to people who ate fewer than one tomato or less than one portion of fruits on a daily basis, who didn’t show the same benefit.

Poor lung function is associated with a higher risk of death from any cause, including chronic obstructive pulmonary disease (aka COPD), lung cancer and heart disease. Even if you don’t smoke, lung function naturally starts to decrease around age 30. As Well+Good quipped, “In other words, if you hope to reap the benefits of fruit consumption, quantity counts.”² Besides the goal of convincing people to stop smoking to reduce the likelihood of developing one or more chronic lung-related diseases, the study noted two major points related to lung function:

• How your lungs function is a predictor of mortality for anyone, including patients with lung disease, as well as people who have never smoked.
• Maintaining lung function and preventing chronic respiratory diseases are also important public health objectives.

Apples and Tomatoes for Better Lung Function

Lead study author Vanessa Garcia-Larsen, an assistant professor in the Johns Hopkins Bloomberg School of Public Health’s department of international health, noted that a diet rich in fruits can slow the natural aging process of your lungs even if you’ve never smoked, and might even help repair damage caused by smoking. Their research was part of the Ageing Lungs in European Cohorts (ALEC) Study, funded by the European Commission and led by Imperial College London.

In 2002, Garcia-Larsen and her colleagues examined the lung function and diet of more than 650 adults from Britain, Norway and Germany, using questionnaires as well as spirometry to measure forced expiratory volume and forced vital capacity (aka the capacity of the lungs to take in oxygen), then tested the lung function of the same individuals a decade later. According to Vanguard:

“The researchers found a more striking diet-lung-function among former smokers, who had around 80 ml slower decline over the 10-year period because their diets were highly rich in tomatoes and fruits. Such a result suggests that the nutrients in their diets are beneficial to repairing the lung damage done by smoking.”³

Also noted in the study was that a major part of the benefit of the foods noted in the study (including bananas and herbal tea) was the flavonoid content, which is corroborated by earlier research: Tomatoes,⁴ as well as apples, are an important source of dietary flavonoids.

An Apple a Day: Better for Your Health Than You Realized

Plenty of studies show how healthy fruit is for you, and apples are no exception. One study⁵ noted the peel in particular as capable of benefiting endothelial function, blood pressure and atherosclerosis and reducing your risk of cardiovascular disease.

In the realm of lung function alone, the research shows that the valuable compounds in apples may help prevent and treat lung cancer,⁶ asthma and respiratory diseases, bronchial hyperactivity and persistent allergic rhinitis, not to mention Type 2 diabetes, asthma⁷ and several other types of cancer. But while it’s true that apples are a healthy food, moderation is key. As the U.S. Department of Agriculture (USDA)⁸ notes, the amounts of fruit you should eat per day vary depending on certain factors:

Children under 8 — 1 to 1 1/2 cups per day

Children and teens — 1 1/2 to 2 cups of fruit per day

Women age 19 to 30 — 2 cups per day, while women older than 30 — 1 1/2 cups per day

Men of any age — 2 cups of fruit per day

What they don’t note, however, is that while fruits offer many vitamins, enzymes and minerals, they should be eaten in moderation due to fructose content, especially if you’re insulin resistant. And please understand that drinking fruit juices does not provide the same benefit as consuming whole fruits.

As far as servings of apples go, the same site broke it down to show that one small apple or half of a large one each constitute one cup, as does 1 cup of sliced, chopped, raw or cooked apples. A 4-ounce snack container of applesauce counts as one-half cup.

Here’s why that’s important: Portion sizes, particularly for those eating a typically Western diet, are often bigger than they should be. And while many think drinking an 8-ounce glass of juice would be good for you, the USDA National Nutrient Database⁹ shows that 8 ounces of apple juice have more sugar and less than a minute amount of fiber compared to a medium-sized apple. (Similar numbers can be assumed for other fruits, as well). Specifically, a typical 8-ounce glass of organic Honeycrisp juice contains:

120 calories

.1 gram of dietary fiber

24 grams of sugar

A medium-sized apple itself has:¹⁰

95 calories

4.4 grams of dietary fiber

18.91 grams of sugar