Researchers looked at studies testing whether natural plant compounds called polyphenols could help people with COPD, a serious lung disease that makes breathing difficult. They found that two specific plant compounds—curcumin (from turmeric) and salidroside (from a plant called rhodiola)—showed promise in improving lung function and reducing inflammation. However, other plant compounds tested didn’t work as well, and one type actually seemed to make things worse. The study included nearly 900 patients across multiple trials, suggesting that not all plant supplements work the same way for lung disease.

The Quick Take

  • What they studied: Whether natural plant compounds found in foods and supplements could help people with COPD (chronic obstructive pulmonary disease) breathe better and reduce lung inflammation
  • Who participated: 894 people with moderate to severe COPD across multiple research studies published before December 2024. Participants were divided into groups receiving either the plant compound or a fake pill (placebo)
  • Key finding: Two plant compounds worked best: curcumin (from turmeric) improved lung function and lowered blood pressure, while salidroside (from rhodiola plant) reduced blood clots and inflammation. However, one compound called anthocyanins actually appeared to make lung function worse
  • What it means for you: If you have COPD, curcumin at 200-500 mg per day might help as an add-on treatment alongside your regular medications. However, you should talk to your doctor before trying any supplements, as some plant compounds may not be safe or effective for everyone

The Research Details

This was a systematic review and meta-analysis, which means researchers searched through all published studies about plant compounds and COPD, then combined the results from the best-quality studies to see what the overall evidence showed. They looked at eight different plant compounds: curcumin, resveratrol, anthocyanins, quercetin, salidroside, beetroot juice, pomegranate juice, and a compound called AKL1.

The researchers only included studies where some patients got the real plant compound while others got a fake pill (placebo), and neither the patients nor doctors knew who got which. This is the gold standard way to test if something actually works. They used special software to combine all the data and look for patterns across the different studies.

The researchers measured several things: how well people’s lungs worked (using a test called FEV1), how much inflammation was in their blood, blood clotting markers, and how much their symptoms bothered them in daily life.

This approach is important because individual studies can sometimes give misleading results by chance. By combining results from many studies with similar designs, researchers can see the true pattern and be more confident about what actually works. This helps doctors and patients make better decisions about which supplements might actually help

The strength of this research comes from including 894 participants across multiple well-designed studies. The researchers were careful to only include studies where patients were randomly assigned to get either the real supplement or a fake pill, which is the most reliable way to test if something works. However, the studies tested different plant compounds and used different doses, which makes it harder to draw firm conclusions. Some results didn’t reach statistical significance overall, though specific subgroups showed promise

What the Results Show

Curcumin (the active ingredient in turmeric) showed the strongest benefits. It significantly lowered systolic blood pressure (the top number in a blood pressure reading) and improved lung function by about 12% or more from the starting point. This is meaningful because better lung function means easier breathing.

Salidroside, a compound from the rhodiola plant, also showed clear benefits. It reduced markers of blood clots and inflammation in the blood, including a protein called TNF-alpha that causes inflammation. It also reduced symptom scores, meaning people felt better day-to-day.

Resveratrol (found in grape skins and red wine) significantly lowered two inflammatory markers in the blood: TNF-alpha and IL-8. These are proteins that cause inflammation in the lungs.

However, anthocyanins (purple and blue pigments in berries) appeared to actually worsen lung function in some measures, which is concerning and needs more study before recommending them.

Other plant compounds tested—quercetin (from onions and apples), pomegranate juice, and a compound called AKL1—did not show significant benefits compared to placebo. This doesn’t necessarily mean they don’t work, but the current evidence isn’t strong enough to recommend them. Some of these compounds simply haven’t been studied enough in COPD patients

This research builds on earlier studies suggesting that plant compounds with antioxidant and anti-inflammatory properties might help COPD. The new finding that different plant compounds work differently is important—it shows that not all ’natural’ or ‘plant-based’ supplements are equally helpful. Previous research hinted at this, but this comprehensive review provides stronger evidence that the specific type of plant compound matters greatly

The studies tested different doses of the same compounds, making it hard to know the perfect amount to take. Some plant compounds were only tested in a few small studies, so we can’t be as confident about them. The concerning finding about anthocyanins was unexpected and needs more research to understand why. The studies were done in different countries with different patient populations, which can affect results. Finally, most studies were relatively short-term, so we don’t know if benefits last over months or years

The Bottom Line

Curcumin at 200-500 mg daily shows moderate evidence of benefit and may be worth discussing with your doctor as an add-on to your regular COPD medications. Salidroside shows promise but needs more research before strong recommendations can be made. Avoid anthocyanin supplements until more safety information is available. Other plant compounds tested don’t have enough evidence to recommend them at this time. Always talk to your doctor before starting any supplement, especially if you take blood thinners or other medications

People with moderate to severe COPD who want to explore additional treatment options should pay attention to this research. Your doctor should be involved in any decision to add supplements. People with mild COPD or those whose lung disease is well-controlled with current medications may not need additional supplements. Pregnant women, people with bleeding disorders, or those taking certain medications should be especially cautious and get medical advice before trying these supplements

If curcumin helps you, you might notice improvements in breathing or reduced symptoms within 2-4 weeks, though some benefits may take 8-12 weeks to appear. Blood pressure improvements might show up within 4-6 weeks. However, these are estimates based on the studies reviewed—individual results vary greatly

Want to Apply This Research?

  • If you try curcumin with your doctor’s approval, track your daily shortness of breath on a scale of 1-10, note how far you can walk before getting winded, and record any changes in cough frequency. Take these measurements at the same time each day for consistency
  • Start by discussing curcumin supplementation with your doctor to get the right dose and make sure it won’t interact with your current medications. If approved, set a daily reminder to take your supplement at the same time each day (such as with breakfast). Keep a simple log of how you feel each day
  • Check in with yourself weekly about breathing ease and daily activities. After 4 weeks, compare your notes to see if there’s any improvement. Share your observations with your doctor at your next appointment. If you’re not seeing benefits after 8-12 weeks, discuss stopping the supplement with your doctor. Continue regular lung function tests as recommended by your doctor to objectively measure any changes

This article summarizes research about plant compounds and COPD but is not medical advice. COPD is a serious condition requiring professional medical care. Do not start, stop, or change any supplements or medications without talking to your doctor first. Some supplements can interact with medications or worsen certain conditions. This research shows promise for some compounds but is not definitive proof they will help you personally. Always work with your healthcare team to make decisions about your treatment plan. If you experience worsening breathing, chest pain, or other concerning symptoms, seek immediate medical attention.