Inflammation can harm your heart, but an “anti-inflammatory” label proves little

Key takeaways

• In the 2017 CANTOS trial of 10,061 heart attack survivors, a drug that blocked one inflammatory signal cut heart attacks, strokes and heart deaths by about 15% at its middle dose without lowering cholesterol, but it also raised fatal infections¹.
• The hs-CRP blood test measures inflammation but can’t tell you its cause; CDC and the American Heart Association advised testing twice, about two weeks apart, and repeating very high results⁴⁵.
• In 17 randomized trials, Mediterranean-style eating lowered hs-CRP and another inflammation marker compared with other diets⁷.
• Fish oil has a mixed record: the VITAL trial found no significant drop in major heart events overall, and a prescription omega-3 trial was clouded by questions about its mineral-oil placebo¹⁰¹¹.
• “Anti-inflammatory” on a supplement or food label isn’t approved by the FDA in advance, and a supplement can’t legally claim to treat a disease such as arthritis or heart disease¹⁵.

The drug tested in the CANTOS trial did nothing to cholesterol. That was the point.

Researchers enrolled 10,061 heart attack survivors in 39 countries, all with a blood test showing lingering inflammation¹. Every three months, each patient got an injection of canakinumab, a drug that blocks one inflammatory signal, or a placebo¹.

At the 150 mg dose, the yearly rate of heart attacks, strokes and heart deaths fell from 4.50 to 3.86 per 100 people, about 15% fewer events¹. LDL cholesterol barely moved¹. A large trial had shown that calming inflammation itself could protect the heart.

There was a price. People on the drug had more fatal infections than people on placebo, and overall death rates were about the same¹. Turning down part of the immune system protected arteries and weakened defenses at the same time.

That trade-off is the “anti-inflammatory” story in small. Inflammation is real, measurable and important. But the word on a tea, a powder or a diet book proves nothing by itself. Here is how to tell the difference.

Short-term inflammation heals you, but the slow, lasting kind does harm

Acute inflammation is the local response your immune system mounts against an infection or an injury, according to a summary from the National Institute of Environmental Health Sciences (NIEHS). It is supposed to switch off once the threat and damage are gone². Our article on how the body repairs itself walks through that process for a cut.

A 2019 review in Nature Medicine, led by David Furman of Stanford University, described a second kind: systemic chronic inflammation²³. This version is low-grade and drags on, and it runs on a partly different set of immune players than a short-term flare².

The review tied this lasting form to heart disease, cancer, diabetes, chronic kidney disease, fatty liver disease, and autoimmune and brain-wasting disorders³. By the authors’ estimate, illnesses driven by chronic inflammation cause more than half of all deaths worldwide².

What drives it? The review named infections, physical inactivity, poor diet, environmental and industrial pollutants, and psychological stress³. NIEHS’s summary also points to poor sleep, and to eating patterns built on refined grains, alcohol and ultra-processed foods². Muscles in motion give off proteins that dampen inflammation, one reason sitting still carries a cost².

That list could have come from a natural-health handbook: move every day, eat whole foods, sleep, ease stress and avoid pollutants. Here, natural-health instincts and mainstream research point the same way. The disagreement starts when a product claims to do the work of those habits.

What the CANTOS trial proved, and what it didn’t

CANTOS, published in the New England Journal of Medicine in 2017, tested a long-standing theory¹. If inflammation helps cause heart attacks, lowering it should prevent some, even without touching cholesterol.

The trial supported that idea. The clearest result came at the 150 mg dose, and the drug lowered hs-CRP, the main blood marker of inflammation, far more than placebo did¹.

It did not show that people lived longer. Deaths from all causes were about equal in the two groups¹. Fatal infections or sepsis occurred at 0.31 per 100 people per year across the drug’s doses, compared with 0.18 on placebo¹.

It also says nothing direct about supplements or diets. CANTOS tested an injected prescription drug in heart attack survivors with an hs-CRP of 2 mg/L or more, on top of standard care¹.

Since then, the drug picture has stayed mixed. In 2023, the FDA approved colchicine, an anti-inflammatory drug, to help prevent heart events in people with or at risk of heart disease, according to the cardiology news site TCTMD⁶. But in a large trial called CLEAR SYNERGY, heart attack patients whose blocked artery was reopened with a catheter procedure saw no drop in major heart events from colchicine. Its lead investigator, Sanjit Jolly, called the result “resoundingly neutral”⁶.

How doctors measure inflammation, and why one number misleads

The most common test is C-reactive protein, or CRP, a protein your liver makes when there is inflammation in your body. MedlinePlus, from the National Library of Medicine, notes that the test can’t show what is causing the inflammation or where it is⁴.

A standard CRP test helps track infections and autoimmune conditions. A high-sensitivity version, hs-CRP, picks up very small rises and is used to estimate heart risk⁴.

Many things nudge CRP up. MedlinePlus lists infections, inflammatory bowel disease, autoimmune disorders, asthma, smoking, polluted air, insomnia, depression, menopause hormone therapy and obesity. Women also tend to run slightly higher⁴.

In 2003, CDC and the American Heart Association published joint guidance on hs-CRP⁵. It set three bands: under 1 mg/L is lower risk, 1 to 3 is average, and over 3 is higher risk⁵. It said testing was optional for adults at intermediate heart risk, and it advised against screening the whole adult population or using repeat tests to track treatment⁵.

The Nature Medicine review flagged another problem. The blood markers doctors know best mostly capture quick, short-lived flare-ups, which makes them weak guides to the slow, lasting kind².

The advice is now shifting. In September 2025, the American College of Cardiology (ACC) published a scientific statement whose writing group was chaired by George Mensah of NIH⁶. Its authors called on guideline writers to start checking hs-CRP widely, together with LDL cholesterol, in people with and without diagnosed heart disease⁶. Coauthor Paul Ridker, who led CANTOS and reports ties to several drug companies, stressed that CRP measures risk rather than causing it⁶.

Eating patterns lower inflammation markers, but single foods are harder to judge

Whole eating patterns have been tested head to head in randomized trials. A 2014 analysis by Lukas Schwingshackl and Georg Hoffmann pooled 17 randomized trials with about 2,300 people⁷.

Compared with other diets, Mediterranean-style eating lowered hs-CRP by nearly 1 mg/L and also cut interleukin-6, another inflammation signal⁷. Blood vessels widened better, a sign of healthier artery linings⁷.

One well-known trial shows both the promise and a catch. In Italy, 180 people with metabolic syndrome, a cluster of risks such as belly fat and high blood sugar, were assigned to a Mediterranean-style diet or a “prudent” diet for two years⁸.

The Mediterranean group’s hs-CRP fell by 1.1 mg/L, compared with 0.1 in the control group⁸. But that group also lost more weight, about 4.0 kg versus 1.2 kg⁸. When a diet lowers inflammation, part of the effect may come through weight loss, better food quality and fewer processed foods at once.

That makes “anti-inflammatory foods” sold one at a time hard to judge. Researchers built a tool called the Dietary Inflammatory Index to rate whole diets. It scores 45 food components by how they affected six inflammation markers in 1,943 published studies⁹. Its creators designed it for research studies, not as a label for a single product⁹.

If your family has a traditional way of eating built on vegetables, beans, whole grains, olive oil or fish, the research suggests it deserves protecting. Our article “Heritage diets hold up in research, and you can keep yours alive” explains how.

Fish oil has a mixed record

The VITAL trial gave 25,871 generally healthy adults either 1 gram of fish oil a day, with 840 mg of omega-3 fats, or a placebo for an average of 5.3 years¹⁰. Major heart events fell 8%, a difference too small to rule out chance¹⁰.

Heart attacks alone were 28% lower, and people who ate little fish seemed to benefit more¹⁰. African American participants had 77% fewer heart attacks, but the study team cautioned that some subgroup findings may be due to chance¹⁰.

Then came REDUCE-IT, which tested a prescription omega-3 drug, icosapent ethyl, sold as Vascepa¹¹. Added to statins, it cut a broad set of heart events by 25%¹¹.

The controversy was the placebo. It was mineral oil, and in that group LDL cholesterol rose about 10% and hs-CRP more than 30%, according to figures discussed when FDA advisers reviewed the drug in 2019¹¹. If the placebo made people a little worse, the drug would look better than it really is.

FDA reviewers ran a worst-case analysis and concluded the LDL rise couldn’t explain the benefit¹¹. In November 2019, all 16 voting members of an FDA advisory committee said the evidence was sufficient, though some thought the mineral oil may have inflated the effect¹¹.

The benefit was clear in people who already had heart disease. In a group with diabetes and other risk factors but no heart disease, the drop wasn’t significant¹¹. The drug also raised the risk of atrial fibrillation, an irregular heartbeat, and of bleeding¹¹.

Two lessons follow. A prescription drug at a set dose isn’t the same as a supplement from the store. And even a large positive trial can depend on what it was compared with.

Turmeric and other “anti-inflammatory” supplements

Turmeric is one of the best-known “anti-inflammatory” supplements. The National Center for Complementary and Integrative Health (NCCIH) says early studies for knee osteoarthritis pain are positive but higher-quality research is needed, and evidence for most other uses is insufficient¹².

Products vary in how much curcumin, turmeric’s main compound, they contain¹². NCCIH also warns that some highly absorbable curcumin products have been linked to liver injury, and that turmeric supplements may be unsafe in pregnancy¹². Our article “Only 1 in 20 treatments tested in animals wins approval for people” explains why curcumin’s lab results haven’t translated well to people.

NSAIDs are proven anti-inflammatories with real risks

Ibuprofen and naproxen are nonsteroidal anti-inflammatory drugs, or NSAIDs, sold over the counter in many products¹³. They are the anti-inflammatories most people already own, and they carry risks that “natural” alternatives are often marketed against.

In July 2015, the FDA strengthened its warning that non-aspirin NSAIDs raise the risk of heart attack and stroke¹³. The risk can begin in the first weeks of use and appears higher at higher doses, in people with or without heart disease¹³. Ibuprofen and naproxen can also blunt the heart protection of low-dose aspirin¹³.

NSAIDs can also cause ulcers and bleeding in the stomach or intestines, sometimes without warning signs¹⁴. The risk rises with older age, heavy drinking, long-term use, smoking, a history of ulcers, and use alongside blood thinners or steroids¹⁴.

The FDA’s advice is to use the lowest dose that works for the shortest time and to avoid doubling up on products that contain NSAIDs¹³. Get medical help right away for chest pain, trouble breathing, sudden weakness on one side or slurred speech¹³. Call your doctor for black or bloody stools or vomit that looks like coffee grounds¹⁴. You can report side effects to the FDA’s MedWatch program¹³.

How to read an “anti-inflammatory” claim

A supplement label may describe effects on normal body function, such as “supports a healthy inflammatory response.” The FDA doesn’t approve these structure/function claims before sale¹⁵. The company must notify the FDA and print a disclaimer that the agency hasn’t evaluated the claim¹⁵.

What the label can’t legally say is that the product treats, cures or prevents a disease, such as arthritis or heart disease¹⁵. That leaves a gap between what the words suggest and what anyone has proven.

What you see	What it can mean	What to ask
“Supports a healthy inflammatory response”	A structure/function claim the FDA did not review15	Did this product lower a marker or improve symptoms in a human trial?
“Lowers inflammation” based on lab studies	Effects seen in cells or animals	Were the doses realistic for a person?
“Clinically shown to reduce CRP”	A blood marker changed	Did anything people feel or experience improve?
“Anti-inflammatory diet” plan or book	A broad eating pattern, sometimes with strict rules	Is it close to a Mediterranean pattern, which has trial evidence7?
“Natural alternative to ibuprofen”	Suggests similar relief with fewer risks	Has it been compared head-to-head with an NSAID?

Here is how the main claims stack up, on a four-level scale.

Claim	What the research shows	Evidence level
Chronic inflammation contributes to heart disease	Lowering it with a drug cut repeat heart events in CANTOS1	Strong evidence
Mediterranean-style eating lowers inflammation markers	Lower hs-CRP and IL-6 across 17 trials7	Strong evidence
Fish oil supplements prevent major heart events in generally healthy adults	No significant drop overall in VITAL10	Evidence says no, or unsafe
Fish oil supplements prevent heart attacks specifically	Heart attacks fell 28% in VITAL, a secondary finding that needs confirming10	Promising but early
A prescription omega-3 drug cuts heart events in high-risk patients on statins	25% fewer events in one large trial, mainly in people with heart disease; its mineral-oil placebo may have inflated the benefit11	Promising but early
Turmeric eases knee osteoarthritis pain	Early pooled studies positive12	Promising but early
Turmeric prevents or treats other conditions	NCCIH calls the evidence insufficient for most other uses12	Not enough evidence
Long-term NSAID use is harmless	Higher heart attack, stroke and bleeding risks1314	Evidence says no, or unsafe

Questions readers ask

The bottom line

Inflammation deserves the attention it gets. The CANTOS trial showed that calming it can lower the risk of repeat heart attacks and strokes, and the cost in infections showed that the immune system isn’t something to turn down casually.

For most people, the steps with the best evidence are the ones natural health has long championed: a Mediterranean-style way of eating, regular movement, good sleep, not smoking and less stress. Treat “anti-inflammatory” on a label as a question, and ask for human evidence on the actual product before you pay for it.

Related reading

• Your body already detoxes itself, and a few everyday habits help it work
• Only 1 in 20 treatments tested in animals wins approval for people
• Heritage diets hold up in research, and you can keep yours alive
• Why supplement labels say ‘supports’ and never say ‘cures’
• Your immune system works more like a team than a volume knob, and some habits help it

Sources

1. Ridker PM, Everett BM, Thuren T, et al., for the CANTOS Trial Group. “Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease.” New England Journal of Medicine, 2017 (University of East Anglia repository copy). ueaeprints.uea.ac.uk
2. National Institute of Environmental Health Sciences. Environmental Factor summary of Furman D, et al., “Chronic Inflammation in the Etiology of Disease Across the Life Span.” NIEHS, January 2020. pubmed.ncbi.nlm.nih.gov
3. Furman D, Campisi J, Verdin E, et al. “Chronic Inflammation in the Etiology of Disease Across the Life Span.” Nature Medicine, 2019;25(12):1822-1832 (UCL Discovery record). discovery.ucl.ac.uk
4. MedlinePlus. “C-Reactive Protein (CRP) Test.” National Library of Medicine, updated June 11, 2025. medlineplus.gov
5. Pearson TA, Mensah GA, Alexander RW, et al. “Markers of Inflammation and Cardiovascular Disease: Application to Clinical and Public Health Practice. A Statement for Healthcare Professionals From the Centers for Disease Control and Prevention and the American Heart Association.” Circulation, 2003;107:499-511. pubmed.ncbi.nlm.nih.gov
6. TCTMD. “ACC: It’s Time for Clinicians to Address Inflammation in CVD” (on Mensah GA, et al., “Inflammation and Cardiovascular Disease: 2025 ACC Scientific Statement,” JACC, 2025). October 3, 2025. tctmd.com
7. Schwingshackl L, Hoffmann G. “Mediterranean Dietary Pattern, Inflammation and Endothelial Function: A Systematic Review and Meta-Analysis of Intervention Trials.” Nutrition, Metabolism & Cardiovascular Diseases, 2014;24:929-939 (University of Vienna record). pubmed.ncbi.nlm.nih.gov
8. Esposito K, Marfella R, Ciotola M, et al. “Effect of a Mediterranean-Style Diet on Endothelial Dysfunction and Markers of Vascular Inflammation in the Metabolic Syndrome: A Randomized Trial.” JAMA, 2004;292(12):1440-1446. iris.unina.it
9. Shivappa N, Steck SE, Hurley TG, Hussey JR, Hébert JR. “Designing and Developing a Literature-Derived, Population-Based Dietary Inflammatory Index.” Public Health Nutrition, 2014;17(8):1689-1696. cambridge.org
10. VITAL Study. “VITAL Signs,” Issue 13 (on Manson JE, et al., New England Journal of Medicine, 2018). vitalstudy.org
11. TCTMD. “FDA Advisors Recommend CVD Event Reduction Claim for Icosapent Ethyl.” November 14, 2019. tctmd.com
12. National Center for Complementary and Integrative Health. “Turmeric.” NIH, updated April 2025. nccih.nih.gov
13. U.S. Food and Drug Administration. “FDA Drug Safety Communication: FDA Strengthens Warning That Non-Aspirin Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) Can Cause Heart Attacks or Strokes.” FDA, July 9, 2015.
14. MedlinePlus. “Ibuprofen.” National Library of Medicine, revised September 15, 2023. medlineplus.gov
15. U.S. Food and Drug Administration. “Structure/Function Claims.” FDA, updated March 28, 2024. fda.gov