Clinical Nutrition: Dietary Guidance for COPD
Consuming more of the right foods and nutrients can help improve health outcomes.
COPD is the third-leading cause of death in the United States.1 The disease, which is most common in current or former smokers, is characterized by obstructed airflow and a heightened inflammatory response in the lungs. Its main symptoms are coughing or wheezing, excessive phlegm and mucus, and shortness of breath.2
Poor food intake and weight loss is a serious concern, since body weight in COPD is linked to mortality. According to Ellen Bowser, MS, RDN, RN, FAND, faculty nutritionist in the Pediatric Pulmonary Division of the University of Florida and coauthor of a 2019 evidence analysis on nutrition in COPD published by the Academy of Nutrition and Dietetics, “The lowest BMI group had the highest mortality rate compared with higher BMI groups. [In addition], there was clear evidence of an association between BMI and lung function.”4
A second reason why nutrition is uniquely important in COPD is that diet may have a direct effect on the underlying biological processes involved in lung function and the progression of COPD—namely, oxidative stress and systemic inflammation.
“The root cause for all disease […] appears to be inflammation,” says Andrew Freeman, MD, an associate professor of cardiology and director of cardiovascular prevention and wellness at National Jewish Health in Denver. “If you can cut that, it appears to be the magic bullet, if there is one.” To combat inflammation, Freeman recommends a low-fat, whole-food, plant-based diet to his cardiology and COPD patients. Although good nutrition doesn’t eliminate the need for medication, it does reduce disease burden, according to Freeman, and his COPD patients have fewer exacerbations (ie, symptom flare-ups) and fewer hospitalizations after changing their lifestyle.
Foods’ and Nutrients’ Protective Effect on Lung Function
• Fruits and vegetables: Repeated observational studies and at least two recent meta-analyses have found that consumption of fresh fruits (especially hard fruits, such as apples) and possibly vegetables is linked with improved lung function and lower risk of developing COPD.5-11 A recent large, population-based study of Swedish men found that for each additional serving of fruits and vegetables consumed, smokers had an 8% lower likelihood of developing COPD, and ex-smokers had a 4% lower risk (over a mean follow up of 13 years).12
Only a few randomized controlled trials of fruit and vegetable consumption have been conducted in patients with COPD, with mixed results.13 However, one notable trial found that patients with COPD with greater intake of fresh fruits and vegetables saw improved FEV1 (an important measure of lung function in COPD) compared with the control group consuming a free diet.14 These benefits may be attributable to the fact that fruits and vegetables are high not only in antioxidants but also in polyphenols, which have anti-inflammatory properties and are associated with improved lung function in COPD.7
• Vitamin D: Several studies have shown a correlation between vitamin D levels and lung function. In addition, many studies, including two randomized controlled trials, have found that supplementation with oral vitamin D reduces risk of COPD exacerbations, particularly in COPD patients who are very low in vitamin D (baseline serum 25(OH)D levels lower than 10 ng/mL).20-22
• A “prudent”/Mediterranean diet pattern heavy in whole plant foods: According to a recent review article, research on dietary patterns consistently suggests that a Western-style diet (ie, a diet high in red and processed meats, refined grains, refined sugars, and desserts) is associated with an increased incidence of COPD and greater severity of the disease. Conversely, prudent/Mediterranean-style diets, which emphasize fruits, vegetables, whole grains, legumes, nuts, fish, and low-fat dairy, are consistently linked to improved lung function and respiratory symptoms, decreased incidence of COPD, and reduced mortality for respiratory diseases.13
• Fish, nuts, and seeds: It’s been suggested that increased intake of fish and omega-3 fatty acids, prevalent in fish and nuts and seeds, might reduce the incidence of COPD or the severity of symptoms, because omega-3 fatty acids have strong anti-inflammatory properties. Indeed, several early studies did show a link between intake of omega-3 fatty acids (especially in the form of fatty fish) on lung function and symptoms of COPD. However, these studies didn’t adjust for other dietary factors.13
• Processed red meats: Processed red meats contain nitrites as well as saturated fatty acids, both of which can trigger inflammation in the lungs and elsewhere. Consumption of processed meats has been linked in multiple studies to poorer lung function, increased risk of COPD, and greater risk of hospital readmission for COPD.24-30
• Soda: Higher levels of soft drink consumption are associated with higher incidence of COPD.31-33 This may be because soft drinks are linked to hyperglycemia, which causes inflammation and is associated with impaired lung function and adverse outcomes in COPD.34-36
• Broth, clear soups, and too much liquid in general: The goal in COPD is “to make sure all the food [COPD patients] are eating and all the beverages they’re drinking are nutrient dense,” according to Jones, and drinking liquids in abundance can make patients feel prematurely full without providing adequate nutrition.
Recommendations for Geriatricians
• Assess energy intake. Since energy intake from food is tied to improved outcomes and lower mortality, it’s imperative that dietitians determine intake during counseling sessions.
• Check vitamin D levels. According to the 2019 Academy of Nutrition and Dietetics evidence analysis, vitamin D status is particularly important if a patient with COPD is having two or more exacerbations per year. Patients who have low levels should take an oral supplement.
• Coach clients on how to time meals. “Because people with COPD oftentimes fatigue very easily, what we encourage them to do is have small, frequent meals,” Bowser says.
According to Jones, patients with COPD should rest before eating. “Don’t do any strenuous activity before you have a meal,” she says. Also, “eat more food earlier in the morning if you’re usually too tired to eat later in the day.”
• Recommend batch meal prep. If clients prepare meals a couple times per week and freeze leftovers, “it’s easier for them to take something out that they’ve prepared and put it in the microwave, [which helps] minimize exertion,” Bowser says.
Finally, though exercise isn’t in the realm of nutrition per se, dietitians should help patients understand its importance. “Diet alone isn’t the only solution,” and exercise “really does some serious wonders,” Freeman says. In combination, nutrition interventions and physical activity can “significantly reduce disease burden and medications.”
— Jamie Santa Cruz is a freelance writer of health and medical topics based in Parker, Colorado.
2. Basics about COPD. Centers for Disease Control and Prevention website. https://www.cdc.gov/copd/basics-about.html. Updated July 19, 2019. Accessed August 21, 2020.
3. Rawal G, Yadav S. Nutrition in chronic obstructive pulmonary disease: a review. J Transl Int Med. 2015;3(4):151-154.
4. Hanson C, Bowser EK, Frankenfield DC, Piemonte TA. Chronic obstructive pulmonary disease: a 2019 evidence analysis center evidence-based practice guideline [published online February 17, 2020]. J Acad Nutr Diet. doi: 10.1016/j.jand.2019.12.001.
5. Miedema I, Feskens EJ, Heederik D, Kromhout D. Dietary determinants of long-term incidence of chronic nonspecific lung diseases. The Zutphen Study. Am J Epidemiol. 1993;138(1):37-45.
6. Butland BK, Fehily AM, Elwood PC. Diet, lung function, and lung function decline in a cohort of 2512 middle aged men. Thorax. 2000;55(2):102-108.
7. Tabak C, Arts IC, Smit HA, Heederik D, Kromhout D. Chronic obstructive pulmonary disease and intake of catechins, flavonols, and flavones: the MORGEN Study. Am J Respir Crit Care Med. 2001;164(1):61-64.
8. Tabak C, Smit HA, Heederik D, Ocké MC, Kromhout D. Diet and chronic obstructive pulmonary disease: independent beneficial effects of fruits, whole grains, and alcohol (the MORGEN study). Clin Exp Allergy. 2001;31(5):747-755.
9. Kaluza J, Harris HR, Linden A, Wolk A. Long-term consumption of fruits and vegetables and risk of chronic obstructive pulmonary disease: a prospective cohort study of women. Int J Epidemiol. 2018;47(6):1897-1909.
10. Zhai H, Wang Y, Jiang W. Fruit and vegetable intake and the risk of chronic obstructive pulmonary disease: a dose-response meta-analysis of observational studies. Biomed Res Int. 2020;2020:3783481.
11. Seyedrezazadeh E, Moghaddam MP, Ansarin K, et al. Dietary factors and risk of chronic obstructive pulmonary disease: a systemic review and meta-analysis. Tanaffos. 2019;18(4):294-309.
12. Kaluza J, Larsson SC, Orsini N, Linden A, Wolk A. Fruit and vegetable consumption and risk of COPD: a prospective cohort study of men. Thorax. 2017;72(6):500-509.
13. Scoditti E, Massaro M, Garbarino S, Toraldo DM. Role of diet in chronic obstructive pulmonary disease prevention and treatment. Nutrients. 2019;11(6):1357.
14. Keranis E, Makris D, Rodopoulou P, et al. Impact of dietary shift to higher-antioxidant foods in COPD: a randomised trial. Eur Respir J. 2010;36(4):774-780.
15. Jacobs DR Jr, Andersen LF, Blomhoff R. Whole-grain consumption is associated with a reduced risk of noncardiovascular, noncancer death attributed to inflammatory diseases in the Iowa Women's Health Study. Am J Clin Nutr. 2007;85(6):1606-1614.
16. Butler LM, Koh WP, Lee HP, Yu MC, London SJ. Dietary fiber and reduced cough with phlegm: a cohort study in Singapore. Am J Respir Crit Care Med. 2004;170(3):279-287.
17. Kan H, Stevens J, Heiss G, Rose KM, London SJ. Dietary fiber, lung function, and chronic obstructive pulmonary disease in the atherosclerosis risk in communities study. Am J Epidemiol. 2008;167(5):570-578.
18. Varraso R, Willett WC, Camargo CA Jr. Prospective study of dietary fiber and risk of chronic obstructive pulmonary disease among US women and men. Am J Epidemiol. 2010;171(7):776-784.
19. Hanson C, Lyden E, Rennard S, et al. The relationship between dietary fiber intake and lung function in the National Health and Nutrition Examination Surveys. Ann Am Thorac Soc. 2016;13(5):643-650.
20. Lehouck A, Mathieu C, Carremans C, et al. High doses of vitamin D to reduce exacerbations in chronic obstructive pulmonary disease: a randomized trial. Ann Intern Med. 2012;156(2):105-114.
21. Rezk NAS, Aly NYA, Hewidy A. Effect of vitamin D replacement in chronic obstructive pulmonary disease patients with vitamin D deficiency. Egypt J Chest Dis Tuberc. 2015;64(2):353-357.
22. Khan DM, Ullah A, Randhawa FA, Iqtadar S, Butt NF, Waheed K. Role of vitamin D in reducing number of acute exacerbations in chronic obstructive pulmonary disease (COPD) patients. Pak J Med Sci. 2017;33(3):610-614.
23. Varraso R, Barr RG, Willett WC, Speizer FE, Camargo CA Jr. Fish intake and risk of chronic obstructive pulmonary disease in 2 large US cohorts. Am J Clin Nutr. 2015;101(2):354-361.
24. Jiang R, Paik DC, Hankinson JL, Barr RG. Cured meat consumption, lung function, and chronic obstructive pulmonary disease among United States adults. Am J Respir Crit Care Med. 2007;175(8):798-804.
25. Varraso R, Jiang R, Barr RG, Willett WC, Camargo CA Jr. Prospective study of cured meats consumption and risk of chronic obstructive pulmonary disease in men. Am J Epidemiol. 2007;166(12):1438-1445.
26. Jiang R, Camargo CA Jr, Varraso R, Paik DC, Willett WC, Barr RG. Consumption of cured meats and prospective risk of chronic obstructive pulmonary disease in women. Am J Clin Nutr. 2008;87(4):1002-1008.
27. Kaluza J, Larsson SC, Linden A, Wolk A. Consumption of unprocessed and processed red meat and the risk of chronic obstructive pulmonary disease: a prospective cohort study of men. Am J Epidemiol. 2016;184(11):829-836.
28. Kaluza J, Harris H, Linden A, Wolk A. Long-term unprocessed and processed red meat consumption and risk of chronic obstructive pulmonary disease: a prospective cohort study of women. Eur J Nutr. 2019;58(2):665-672.
29. de Batlle J, Mendez M, Romieu I, et al. Cured meat consumption increases risk of readmission in COPD patients. Eur Respir J. 2012;40(3):555-560.
30. Salari-Moghaddam A, Milajerdi A, Larijani B, Esmaillzadeh A. Processed red meat intake and risk of COPD: a systematic review and dose-response meta-analysis of prospective cohort studies. Clin Nutr. 2018;38(3):1109-1116.
31. Shi Z, Dal Grande E, Taylor AW, Gill TK, Adams R, Wittert GA. Association between soft drink consumption and asthma and chronic obstructive pulmonary disease among adults in Australia. Respirology. 2012;17(2):363-369.
32. DeChristopher LR, Uribarri J, Tucker KL. Intake of high fructose corn syrup sweetened soft drinks is associated with prevalent chronic bronchitis in U.S. Adults, ages 20–55 y. Nutr J. 2015;14:107.
33. Min JE, Huh DA, Moon KW. The joint effects of some beverages intake and smoking on chronic obstructive pulmonary disease in Korean adults: data analysis of the Korea National Health and Nutrition Examination Survey (KNHANES), 2008-2015. Int J Environ Res Public Health. 2020;17(7):2611.
34. Esposito K, Nappo F, Marfella R, et al. Inflammatory cytokine concentrations are acutely increased by hyperglycemia in humans: Role of oxidative stress. Circulation. 2002;106(16):2067-2072.
35. Walter RE, Beiser A, Givelber RJ, O’Connor GT, Gottlieb DJ. Association between glycemic state and lung function: the Framingham Heart Study. Am J Respir Crit Care Med. 2003;167(6):911-916.
36. Baker EH, Janaway CH, Philips BJ, et al. Hyperglycaemia is associated with poor outcomes in patients admitted to hospital with acute exacerbations of chronic obstructive pulmonary disease. Thorax. 2006;61(4):284-289.