Herbs for Inflammation: What the Evidence Actually Shows, Herb by Herb

Lists of “anti-inflammatory herbs” are everywhere, but does any of it hold up? Short version: none of the evidence we checked shows that any herb treats, cures or prevents an inflammatory disease. Most of those lists rest on lab and animal studies of plant extracts, not on evidence that eating or drinking the herb reduces inflammation in people. Below, we check each herb they usually name against the U.S. National Center for Complementary and Integrative Health (NCCIH) and published systematic reviews. If you have arthritis, gum disease, asthma or any other inflammatory condition, talk to your doctor before adding a supplement, especially if you take other medicines.

At a glance

What “anti-inflammatory” usually means in these lists

Research on plants and inflammation comes in levels. There are test-tube studies of an extract or isolated compound, animal studies, and human trials, which often test a concentrated supplement instead of the herb you cook with. The strongest evidence is a systematic review or meta-analysis of human trials, and NIH’s NCCIH summaries are a good guide to where that evidence stands. They’re our main yardstick below.

Turmeric and ginger: the most studied

Turmeric and ginger are spices, not leafy herbs, but they have the most human research on inflammatory conditions of any of these plants, so they set the bar for the rest.

• Turmeric. Several meta-analyses have looked at oral turmeric or curcumin for osteoarthritis. NCCIH’s verdict for knee osteoarthritis is that the initial evidence is positive, but higher-quality evidence is needed. Overall, NCCIH says not enough is known to conclude definitively whether turmeric or curcumin is beneficial for any health purpose. Safety matters here. Liver damage has been reported in some people taking turmeric supplements, with cases linked to products formulated for higher bioavailability,¹ and LiverTox calls turmeric the most common cause of clinically apparent herbal liver injury in the United States.⁹ That’s about supplements, not turmeric in your cooking. See turmeric.
• Ginger. NCCIH says ginger dietary supplements might be helpful for symptoms of knee osteoarthritis.² See ginger.

Holy basil (tulsi)

Holy basil, Ocimum tenuiflorum, is native to tropical and subtropical Asia through the western Pacific. NCCIH has no fact sheet on it.¹⁰ The main systematic review, by Jamshidi and Cohen (2017), found 24 human studies on metabolic disorders, cardiovascular disease, immunity and neurocognition. All reported favorable outcomes, and none reported significant adverse events. But the authors judged only a minority of the studies to be high quality, said effects may have been overestimated, and called for more work on mechanisms, dosage and dose form.³ That review doesn’t establish holy basil as a treatment for arthritis, fibromyalgia or any inflammatory condition.

The compound that usually gets the credit is eugenol. But in a Thai analysis of holy basil essential oils, the dominant aroma compound was methyl eugenol, a different molecule, at 683.90 µg/mL in red holy basil oil. White holy basil oil in the same study had 98.44 µg/mL.¹¹ So oil composition differs even between holy basil types.

Hibiscus

A 2022 systematic review and meta-analysis of Hibiscus sabdariffa included 17 longer-term randomized trials. Hibiscus lowered systolic blood pressure more than placebo, and the authors called for more studies to pin down an effective dose and treatment duration.⁴ The abstract reports on blood pressure and cardiometabolic markers, not inflammation. We didn’t find a systematic review supporting claims that hibiscus eases kidney inflammation.

Chamomile

NCCIH says chamomile is promoted for colds, indigestion, anxiety and insomnia, and used on the skin and as a mouthwash. Studies of chamomile for specific conditions “have not produced sufficient reliable evidence to rate clinical usefulness.” Small studies suggest chamomile mouthwashes may help with mouth swelling or irritation caused by cancer treatment.⁵

Safety: chamomile is likely safe in the amounts found in teas. But people allergic to related plants like ragweed, chrysanthemums, marigolds or daisies can react to it, and interactions with warfarin and some drugs metabolized by the liver have been reported.⁵

Aloe vera

NCCIH says clinical research suggests topical aloe gel may speed burn healing and reduce burn pain. Taken by mouth, there isn’t enough reliable information to say whether aloe helps conditions including irritable bowel syndrome and ulcerative colitis. And oral aloe carries real risks. Aloe latex can cause abdominal pain, cramps and diarrhea. The FDA required aloe latex to be removed from over-the-counter laxatives because of a lack of safety data. Oral aloe leaf extracts have been linked to cases of acute hepatitis.⁶

Sage

NCCIH says only small amounts of research have been done on sage for health conditions, so no definitive conclusions are possible. Its sage page doesn’t discuss inflammation, gum disease or arthritis. Sage is likely safe in food amounts, but it contains thujone, which can be toxic in large amounts, and it may be unsafe during pregnancy.⁷ The European Medicines Agency has concluded that the benefits of sage essential oil don’t outweigh its risks.¹²

Peppermint and other mints

NCCIH says very little research has been done on peppermint leaf. Peppermint oil in enteric-coated capsules may improve irritable bowel syndrome symptoms in adults.⁸ That’s a finding about a concentrated oil and a bowel condition, not evidence that mint reduces lung or joint inflammation. We didn’t find an NIH summary or systematic review supporting mint for asthma.

Rosemary, cilantro, parsley and bay leaf

We didn’t find an NCCIH fact sheet or systematic review of human trials on these herbs and inflammation, and NCCIH has no fact sheet on bay leaf.¹⁰ We couldn’t trace the claims made about them in popular lists:

• Rosemary. We couldn’t trace claims that rosmarinic acid blocks prostaglandin production in the body to human evidence.
• Cilantro. We couldn’t trace claims that it relieves arthritis pain through opioid pathways. PROSEA describes the volatile compounds of the leaf as more than 80% aldehydes.¹³
• Parsley. We couldn’t trace claims that parsley’s vitamin C or apigenin stop inflammation to human evidence.
• Bay leaf. Parthenolide often gets the credit, but it isn’t among the main components reported for bay leaf oil, which is led by 1,8-cineole, sabinene and linalool.¹⁴

The bottom line

Cook with these herbs for flavor. As medicine, the human evidence is thin for almost all of them. Turmeric and ginger, the most researched, have it for supplements in specific conditions, with safety caveats. If you’re thinking about an herbal supplement for an inflammatory condition, talk to a health care provider first, especially if you’re pregnant or take blood thinners or other medicines.

Related

• Holy basil, holy basil vs basil
• Turmeric, cooking with turmeric
• Ginger, cooking with ginger
• Sage, rosemary, mint, peppermint
• Cilantro, parsley, bay leaves