Plant-centered diets improve health among patients with lung diseases

Key takeaways:

• Plant-centered diets include whole grains, fruits, vegetables and nuts.
• Registered dietitian nutritionists offer tailored nutrition and coaching to patients based on their lung disease/condition.

Editor’s Note: This is part two of a two-part Healio Exclusive series on nutrition and lung health. Part one can be viewed here.

Diet is an important factor in lung health, and registered dietitian nutritionists support patients with lung diseases by creating tailored, individualized diet plans.

Mariah K. Jackson

“Currently, clinicians may not automatically think of diet as an intervention for lung health, but growing research is showing that diet, especially nutrient-rich plant-based diets, have positive impacts on long-term lung health,” Mariah K. Jackson, PhD, RDN, LMNT, assistant professor in the medical nutrition program in the College of Allied Health Professions at the University of Nebraska Medical Center, told Healio.

Diets for lung health

At the moment, no specific diet is officially recommended for lung health. But in a 2024 study published in Chronic Obstructive Pulmonary Diseases: Journal of the COPD Foundation, Jackson and colleagues found that 1,351 ever current and former adult smokers with a diet high in nutritionally rich, plant-centered foods had lower odds for emphysema.

Researchers split up the total cohort into five groups based on the average A Priori Diet Quality Score (APDQS) from three different times (0, 7 and 20 years), and individuals who consumed more nutritionally rich plant-centered foods belonged to a higher quintile.

More adults in the lowest APDQS quintile had emphysema than those in the highest quintile (25.4% vs. 4.5%). Additionally, researchers found reduced odds for emphysema among those in the highest vs. lowest APDQS quintile (adjusted OR = 0.44; 95% CI, 0.19-0.99; P = .008) in a model adjusted for several covariates.

In 2024, ERJ Open Research reported that consuming a healthy plant-based diet or a pro-vegetarian diet lowers an individual’s likelihood for obstructive sleep apnea.

This study used data from the National Health and Nutrition Examination Survey and analyzed 14,210 individuals (49.4% men) who reported their food consumption over the last 24 hours.

Researchers observed reduced odds for OSA among those with high adherence to a healthy plant-based diet that included whole grains, vegetables, fruit, nuts, tea and coffee (OR = 0.83; 95% CI, 0.69-1.01) and those with high adherence to a pro-vegetarian diet (OR = 0.84; 95% CI, 0.68-1.05) vs. individuals reporting low adherence.

In contrast, the odds for OSA increased among individuals reporting high adherence to an unhealthy plant-based diet that included refined grains, sugary drinks, sweets/desserts and salty foods (OR = 1.22; 95% CI, 1-1.49).

In terms of asthma, a 2018 study published in European Respiratory Journal found a link between a healthy diet high in fruits, vegetables and whole grains and fewer asthma symptoms, as well as greater asthma control.

Researchers reported decreased odds for experiencing asthma symptoms among both men (aOR = 0.67; 95% CI, 0.60-0.75) and women (aOR = 0.79; 95% CI, 0.75-0.84) who maintained a healthier diet.

Further, the odds for poorly controlled asthma symptoms fell among men (OR = 0.39; 95% CI, 0.18-0.84) and women (OR = 0.73; 95% CI, 0.53-1.01) with healthy diets.

From study to table

“There is a growing body of evidence that nutrient-rich plant-based diets that are high in fiber, fruits, vegetables, whole grains, as well as omega-3 fatty acids, are important for long-term lung health,” Jackson told Healio.

“A Mediterranean-style diet is a popular choice that follows this nutrient-rich pattern. This type of diet works well for most chronic disease prevention including cancer, heart disease and diabetes,” Jackson added.

Notably, the Mediterranean diet was named the best overall diet by the editors of U.S. News and World Report in 2025, marking the eighth year in a row it has held the top spot.

Kathleen Garcia-Benson

“In the Mediterranean diet, there’s going to be a priority of minimally processed foods,” Kathleen Garcia-Benson, RDN, CSSD, LD, NASM-CPT, NBC-HWC, registered dietitian specializing in PCOS/women’s health, sports nutrition and digestive health at Top Nutrition Coaching, told Healio.

When asked how clinicians can help their patients adopt the Mediterranean diet, Jackson recommended advising them on what should be on their plate.

“I like to break it down more to tangible goals such as working toward a goal of making two-thirds of your plate made of nutrient-rich plant foods (fruit, vegetables, whole grains, beans, nuts) and one-third of your plate a lean protein source (fish, poultry),” Jackson told Healio. “You do not have to strictly be vegetarian or vegan but work toward a goal of more whole plant foods to increase nutrient abundance.”

As fresh fruits and vegetables may be too expensive for some patients, clinicians should also note that frozen and canned fruits and vegetables are OK, Jackson said.

“Frozen and canned fruits and vegetables are still nutrient-rich and have other benefits of longer storage and being often more cost-effective,” Jackson told Healio. “Worried about the salt in canned beans? Rinse them off and they are ready to be added to increase the plant power of your meals. I like to throw a can of black beans or pinto beans in with my taco meat.”

According to Jackson, the key to helping patients eat healthier is adding rather than taking away.

“By focusing on what I can add to my meal to make it more plant-based and nutrient-rich vs. a ‘take away mindset,’ I can work toward that balance of plant and animal-based foods,” Jackson said.

Garcia-Benson further emphasized this idea.

“As a dietitian, I really like to focus on what we can include,” Garcia-Benson said. “It’s always a little bit easier to focus on things to do rather than things not to do.

“When we are prioritizing those kinds of foods, we can naturally reduce some of the intake of an excess amount of saturated fats or excessive amounts of added sugars, things that can contribute to more chronic conditions and make it a little bit more challenging,” she continued.

Diets for patients with lung diseases/conditions

Although nutrient-rich plant-centered and Mediterranean diets benefit lung health, the best diet may differ depending on lung disease/condition, Robert Wharton, MD, pulmonary and critical care fellow at Johns Hopkins Hospital, told Healio.

“If I know you have cystic fibrosis, I’m going to go in a different direction than if I know you have interstitial lung disease, your BMI is 17 [kg/m²]and you’re very frail,” Wharton said.

In several lung diseases, Wharton noted that weight gain/loss can negatively impact the patient, so maintaining a healthy weight is often the main motivation behind diet.

“Overweight/obesity reduces the total volume in the lungs and causes restrictive lung disease,” Wharton told Healio.

“Being overweight or obese is associated with metabolic syndrome and insulin resistance, and we think that the metabolic syndrome plays a role in the severity and refractoriness of asthma,” Wharton added.

As Healio previously reported, high HbA1c levels consistent with prediabetes were associated with worse asthma control in a population of urban children in the AIRWEIGHS Study.

Additionally, a 2024 study published in JAMA Internal Medicine found a link between metformin use, which improves insulin resistance, and fewer asthma attacks in adults with asthma and type 2 diabetes.

Wharton also said patients with obesity face an elevated risk for some harmful breathing-related conditions, such as OSA and obesity hypoventilation syndrome.

Switching to pulmonary diseases where patients frequently experience weight loss rather than weight gain, Wharton highlighted the struggle of getting these patients to eat enough.

“In cystic fibrosis, which is more of a multisystem disease, patients often lose weight because not only is there increased respiratory muscle demand, but [there is] also pancreatic insufficiency,” he told Healio. “It’s hard to really get effective calories in.”

Notably, the Cystic Fibrosis Foundation has a Nutritional Basics webpage to help clinicians making nutritional recommendations to their patients with cystic fibrosis. The webpage highlights BMI recommendations, ways patients can get extra calories in and the importance of drinking water.

The Cystic Fibrosis Foundation also released a Nutrition Position Paper in 2023, in which they considered how cystic fibrosis transmembrane regulator (CFTR) highly effective modulator therapy (HEMT) has changed food recommendations.

“We used to recommend that those patients have double portions and double calories,” Wharton told Healio. “Then they came out with some new drugs, the CFTR modulators, that really changed the course of the disease.”

According to the position paper, “people with CF (pwCF) are living longer, particularly with the advent of HEMT. The traditional high fat, high calorie CF diet may have negative nutritional and cardiovascular consequences as pwCF age.”

Patients with ILD also can struggle with weight loss due to pulmonary cachexia and treatment side effects, Wharton said.

“Pulmonary cachexia is basically an increased metabolic demand due to having to use a lot of energy to breathe,” Wharton told Healio.

“Patients with interstitial lung disease are sometimes prescribed antifibrotic agents that can cause a lot of diarrhea and GI upset, so it’s hard for them to maintain an adequate caloric intake,” he said.

Similar to the Cystic Fibrosis Foundation, the University of California San Francisco Health has nutrition guidelines for patients with ILD. According to these guidelines, patients with ILD should focus on eating protein, fiber, fresh fruits and vegetables and limiting foods high in sodium, caffeinated drinks and alcohol.

Other recommendations include “achieve and maintain a healthy BMI,” “eat several small meals of high nutritional value” and “eat your main meal early in the day.”

In terms of research in this area, Paola Faverio, MD, and colleagues conducted a literature review of observational and interventional studies on nutrition/diet/weight in patients with idiopathic pulmonary fibrosis published in Nutrients in 2020.

Based on their findings, Faverio and colleagues wrote, “More attention should be devoted to the assessment of the undernutrition and overnutrition, as well as of muscle strength and physical performance in IPF patients, taking also into account that an adequate clinical management of gastrointestinal complications makes IPF drug treatments more feasible.”

Additionally, a pilot trial presented at the 2024 European Respiratory Society International Congress found that a 12-week dietetic intervention trial in patients with ILD and malnutrition was feasible and helped patients stop losing weight.

In all lung diseases, Wharton emphasized weight management and inflammation control.

Collaboration between pulmonologists, nutritionists

Although there is clear overlap between lung health and nutrition, Wharton said registered dietitian nutritionists (RDNs) and pulmonologists do not have a shared space.

“The way new systems are built in medicine, it would take us showing in a compelling manner that it’s worth the lift or the cost to have pulmonologists and dietitians in the same space,” Wharton told Healio.

Wharton highlighted that RDNs are present in the critical care setting to assist in tube feeding and IV nutrition, but collaboration outside of the hospital is lacking and “a little bit disappointing.”

“Pulmonologists should recognize that collaboration with nutritionists is important,” Wharton told Healio.

There are many advantages to patients with lung diseases/conditions seeing an RDN, one of which is diet plans tailored according to the patient’s needs, Garcia-Benson said.

“The tailored part is really helpful from dietitians, especially on the coaching side of things and when there are any metabolic comorbidities, such as diabetes or cardiovascular disease, or if they’re at a weight that’s not supportive for it for them,” Garcia-Benson said.

One example showing the benefits of a tailored nutrition approach can be found in patients who struggle with shortness of breath.

“If [patients with lung diseases/conditions] are having challenges like difficulty eating due to shortness of breath, then they are at an increased risk for various deficiencies [and an] increased risk of not being able to eat enough calories overall,” Garcia-Benson said.

“If that’s the case, then we’re not just going to say eat more. We’re going to have some switches to what they’re eating to make it a little bit easier to eat foods and really focus on the nutrient density of them … making sure that they’re getting enough protein, fats and nutrient dense sources of carbohydrates,” she continued.

Garcia-Benson also said RDNs can help patients with lung diseases/conditions achieve weight gain or weight loss through nutrition, and Wharton called this even more important today due to the rise in GLP-1 receptor agonists and glucose-dependent insulinotropic polypeptide (GIP) agonists.

“We should be paying attention to nutrition over and above just maintaining normal weight,” Wharton told Healio. “With the recent development of GLP-1 receptor agonists and GIP agonists, which have really been a huge advancement in health and help people lose weight, I think we shouldn’t forget about diet and other important aspects of staying healthy.

“You still need to get all the right micronutrients even if you’re on a medication that increases your insulin sensitivity and decreases your appetite,” Wharton said.

Garcia-Benson noted that RDNs can assess how respiratory medications are impacting the patient and make diet adjustments based on this information.

“Sometimes someone’s on a corticosteroid that can cause them to have changes in their appetite,” Garcia-Benson told Healio. “Other medications might have changes in blood sugar levels, or it might have side effects like causing micronutrient depletions or potential deficiencies down the line.

“We can have strategies to counteract those,” she said.

With tailored nutrition and coaching, Jackson said RDNs provide a service that may be easier for some patients to follow than other interventions.

“Smoking is still a leading cause of lung diseases, and smoking cessation is a hard road; therefore, it is important to offer our patients other avenues to have a complementary intervention for their lung health,” Jackson told Healio.

In addition to working one-on-one with patients, recent research has investigated the role RDNs play in culinary medicine, which Nathan I. Wood, MD, MHS, Chef, DipABLM, DABOM, and colleagues defined in a review published in Journal of Healthcare Leadership as “an evidence-based, interprofessional field of medicine that combines culinary arts, nutrition science, and medical education to prevent and treat diet-related disease.”

In this review, Wood and colleagues highlighted the importance of involvement from physicians, chefs and RDNs in leading culinary medicine sessions.

“When physicians, chefs, and RDNs collaborate, their complementary areas of expertise synchronize and synergize to enable evidence-based culinary medicine programming,” Wood and colleagues wrote.

Additionally, authors of a 2023 report published in Journal of the Academy of Nutrition and Dietetics said, “employed with the Essential Practice Competencies, RDNs can take the lead — and partner with interprofessional teams, as appropriate — to develop and facilitate effective [culinary medicine] interventions in [teaching kitchen] settings.”

Wharton told Healio culinary medicine has major value for both those teaching and participating because cooking is an essential skill that some may have never learned.

“I think part of the problem that leads to people having bad diet … is that we weren’t actually taught systematically,” Wharton said. “Not everyone learns from their parents how to cook a good meal, and that contributes to the some of the dietary problems we have in this country.”

One notable culinary medicine program at UT Southwestern is run by Jaclyn Albin, MD, and Milette Siler, RD, LD, CCMS.

According to the UT Southwestern Medical Center website, “UT Southwestern was the first medical center to license the Health meets Food educational curriculum from the American College of Culinary Medicine, which now includes a network of more than 60 medical centers and training programs that are leading the change in how health care professionals are trained to think about wellness and healthy eating.”

Based on all these skills and services, collaboration between pulmonologists and RDNs benefits patients and needs to be exercised more often.

“Pulmonologists should consider registered dietitians as a key part of the health care team and comprehensive health care planning,” Jackson told Healio. “The Academy of Nutrition and Dietetics has great resources for the role of nutrition in chronic diseases, including COPD, as well as tools to find a registered dietitian in your area.”

References:

• Andrianasolo RM, et al. Eur Respir J. 2018;doi:10.1183/13993003.02572-2017.
• Cystic Fibrosis Foundation. Nutritional basics. Accessed April 8, 2025.
• Faverio P, et al. Nutrients. 2020;doi:10.3390/nu12041131.
• Jackson MK, et al. Chronic Obstr Pulm Dis. 2024;doi:10.15326/jcopdf.2023.0437.
• Kahai R, et al. Late breaking abstract – Dietetic intervention in malnourished patients with interstitial lung disease (ILD): A pilot trial. Presented at: European Respiratory Society International Congress; Sept. 7-11, 2024; Vienna.
• Lee B, et al. JAMA Intern Med. 2024;doi:10.1001/jamainternmed.2024.5982.
• Leonard A, et al. J Cyst Fibros. 2023;doi:10.1016/j.jcf.2023.05.010.
• Mediterranean diet. Reviewed March 7, 2024. Accessed April 2, 2025.
• Melaku YA, et al. ERJ Open Res. 2024;doi:10.1183/23120541.00739-2023.
• Pham H, et al. Association between hemoglobin A1c and asthma outcomes among children with asthma. Presented at: American Thoracic Society International Conference; May 18-22, 2023; San Diego.
• Thomas OW, et al. J Acad Nutr Diet. 2023;doi:10.1016/j.jand.2023.07.006.
• UCSF Health. ILD Nutrition Manual: General guidelines for eating healthy. Accessed April 8, 2025.
• U.S. News releases the 2025 edition of best diets. Available at: Published Jan. 3, 2025. Accessed April 2, 2025.
• UT Southwestern Medical Center. Culinary Medicine. Accessed April 21, 2025.
• Wood NI, et al. J Healthc Leadersh. 2023;doi:10.2147/JHL.S389429.

For more information:

Kathleen Garcia-Benson, RDN, CSSD, LD, NASM-CPT, NBC-HWC, can be reached at [email protected].

Mariah K. Jackson, PhD, RDN, LMNT, can be reached at [email protected].

Robert Wharton, MD, can be reached at [email protected].