Eating More Fiber May Lead to Healthier Lungs

Research suggests getting enough fiber is tied to better lung function and reduced risk of chronic illness.

athletic young woman eating high-fiber cereal with berries

Updated on November 3, 2023.

Fewer than 1 in 10 adults in the United States eat the daily recommended amount of fiber, according to the federal government. For women, that recommendation is between 22 and 28 grams of fiber each day. For men, it ranges from 28 to 34 grams. 

Among many health benefits, eating enough fiber can lower the risk of heart disease and stroke, help manage diabetes, and contribute to maintaining a healthy weight. And now, studies increasingly suggest that adequate dietary fiber may help your lungs work better, too.

Fiber and lung function 

One such study, published in Annals of the American Thoracic Society in 2016, examined data from more than 1,900 men and women in the National Health and Nutrition Examination Surveys (NHANES). Researchers found that participants who ate the least fiber had worse lung function than those who ate the most. Eating a diet rich in fruits, vegetables, and legumes was associated with increased lung function, though eating whole grains was not.

But other research suggests that whole grains—and particularly cereal grains such as oats, wheat, and barley—are also good for lungs. For example, a European Journal of Nutrition study published in 2020 analyzed data from 1,557 women and found that a diet high in fiber from fruit and cereals (though not from vegetables) reduced the risk of developing chronic obstructive pulmonary disease (COPD). Eating just 16.3 daily grams of fiber from cereals, or the amount found in about 1 1/2 cups of old fashioned oats, made a difference.  

Another large study of more than 367,000 people published in BMC Medicine in 2015 suggested that consuming more whole grains was linked to a lower chance of death from respiratory ailments in addition to other causes.

Fiber, inflammation, and gut bacteria

Both the 2016 and 2020 studies suggested that fiber bolsters lung function for two reasons. The first is that fiber helps counter inflammation, a key characteristic of both asthma and COPD. Fiber does this by helping to keep C-reactive protein and IL-6 molecules in check; elevated levels of these proteins in your blood indicate inflammation and have been linked to worsened lung function.

The second way fiber helps has to do with your gut. Eating a sufficient amount of fiber may change the mix of microorganisms that live in your gastrointestinal tract. This could result in more production of short-chain fatty acids (SCFAs), compounds that can help promote a healthy immune system and contribute to the protection of your lungs.

Eat for your lungs

Getting more fiber doesn’t have to mean eating dry wheat bran. A variety of delicious fruits, vegetables, legumes, nuts, and whole grains are packed with it. Good sources include:

  • Beans, especially navy beans, which have 19 grams of fiber per 1 cup
  • Artichokes
  • Peas
  • Berries
  • Pears
  • High-fiber breakfast cereal
  • Brown rice 
  • Quinoa
  • Whole-grain pasta and bread

Many fiber-rich foods also deliver a dose of antioxidants, micronutrients that help prevent cell damage and have been shown to improve overall health. For example, citrus fruits, broccoli, and tomatoes are good sources of both fiber and vitamin C, an antioxidant that helps protect lungs from infection.

Some healthy eating plans, such as the DASH Diet and the Mediterranean diet, emphasize fiber, and provide guidelines for including adequate amounts in your everyday meals.

The bottom line

If you’re among the 93 percent of Americans who aren’t getting enough fiber, consider joining that other 7 percent. High-fiber, plant-based foods not only add color and variety to your meals, research shows that they may be particularly healthy for your lungs. It can be as simple as swapping your breads, pastas, and cereals for whole-grain versions, and snacking on whole fruits and vegetables instead of more processed foods.

Article sources open article sources

USDA Nutrition. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020.
MedlinePlus. Fiber. Page last reviewed July 25, 2022.
USDA Agricultural Research Service. What We Eat in America: Nutrient intakes from food by gender and age. National Health and Nutrition Examination Survey (NHANES) 2009-10.
UpToDate. Patient Education: High-Fiber Diet (Beyond the Basics). Page last updated September 7, 2022.
Hanson C, Lynden E, Rennard S, et al. The Relationship Between Dietary Fiber Intake and Lung Function in the National Health and Nutrition Examination Surveys. Annals of the American Thoracic Society. 2016;13(5).
Szmidt MK, Kaluza J, Harris HR, et al. Long-term dietary fiber intake and risk of chronic obstructive pulmonary disease: A prospective cohort study of women. European Journal of Nutrition. 2020;59:1869-1879.
Huang T, Xu M, Lee A, et al. Consumption of whole grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals. BMC Med. 2015 Mar 24;13:59.
USDA FoodData Central. Oats, Whole Grain, Rolled, Old Fashioned. Accessed on May 23, 2023.
Dashdiet.org. What is the DASH Diet? Accessed on May 23, 2023.
Mayo Clinic. DASH Diet: Healthy eating to lower your blood pressure. June 25, 2021.
USDA Food and Nutrition Service. 2015 USDA Food Patterns Resource: Healthy Mediterranean-Style Pattern: Recommended Intake Amounts. Page last updated October 13, 2016.
Harvard T. Chan School of Public Health. Antioxidants. Accessed on May 23, 2022.
USDA Nutrition. Dietary Guidelines for Americans. Food Sources of Dietary Fiber. 2019.
Harvard T. Chan School of Public Health. Vitamin C. Page last reviewed March 2023.
Centers for Disease Control and Prevention. Fat-Soluble Vitamins and Micronutrients: Vitamins A and E and Carotenoids. 2002.
USDA FoodData Central. Beans, Navy, Mature Seeds, Cooked, Boiled, Without Salt. Accessed on May 23, 2023.

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