Supplement
Resveratrol
Resveratrol is the cautionary tale the supplement industry least likes to retell. The red-wine polyphenol rose on striking early animal work and sirtuin biology, attracted hundreds of millions in investment, and then failed to deliver in normal-diet animals and in human trials. It remains one of the most instructive stories in longevity science — and it is still sold as if none of that happened.
Quick verdict
Meta-analysis of randomised trials finds no metabolic benefit in people without diabetes, and a prospective cohort found dietary resveratrol unrelated to mortality. The famous mouse lifespan result came from mice on a high-fat diet and did not generalise. What survives is a possible modest effect in type 2 diabetes — a medical question, not a longevity one.
The assessment
Claim by claim
Each claim is graded on its own evidence. A grade for one claim says nothing about the others.
| Claim | What was measured | Evidence |
|---|---|---|
| Higher resveratrol exposure is associated with lower mortality | Lifespan | Insufficient |
| Extends human lifespan | Lifespan | Insufficient |
| Improves glucose control and insulin sensitivity in people without diabetes | Surrogate biomarker | Against |
Higher resveratrol exposure is associated with lower mortality
Insufficient evidenceOutcome measured: Lifespan — Death from any cause was measured.
The InCHIANTI cohort measured urinary resveratrol metabolites — an objective marker of intake — in 783 older adults and followed them for nine years. Resveratrol exposure was unrelated to mortality, cardiovascular disease, cancer or inflammation.
Why this grade — the appraisal in full
Too little credible research exists to judge the claim either way.
- Strongest study design. Prospective cohort with 783 participants.
- Human research volume. 1 human study, 783 participants in total.
- What was measured. 1 human study measured a clinical or functional outcome rather than a laboratory marker alone.
- Replication. The supporting result has not been independently replicated in humans.
- Study duration. Longest human study ran 468 weeks.
Limitations. Observational, dietary-level exposure rather than supplement doses; it cannot rule out effects at pharmacological doses — the randomised evidence above addresses those.
| Study | Design | Population | Finding |
|---|---|---|---|
| [1]Resveratrol levels and all-cause mortality in older community-dwelling adultsJAMA internal medicine · 2014 · PMID 24819981 | Prospective cohortHuman | 783 participantsMixed population | Found no effectInCHIANTI: urinary resveratrol metabolites unrelated to all-cause mortality over 9 years. |
Extends human lifespan
Insufficient evidenceOutcome measured: Lifespan — Death from any cause was measured.
The claim that launched a thousand supplements rests on a 2006 study of mice on a high-fat diet. In normally fed mice, the NIA's rigorous multi-site testing programme found no lifespan extension, and no human lifespan study exists.
Why this grade — the appraisal in full
Too little credible research exists to judge the claim either way.
- Available research. No usable studies are linked to this claim.
Limitations. The founding animal result did not replicate outside metabolically stressed animals.
Improves glucose control and insulin sensitivity in people without diabetes
Evidence against the claimOutcome measured: Surrogate biomarker — A laboratory marker measured as a stand-in for health. A change here does not by itself demonstrate a health benefit.
A meta-analysis of eleven randomised trials found no significant effect of resveratrol on glucose or insulin measures in non-diabetic participants. A signal exists in type 2 diabetes — but the supplement is overwhelmingly sold to healthy people, for whom the pooled answer is no.
Why this grade — the appraisal in full
Well-conducted human research indicates the claimed effect does not occur, or is too small to matter.
- Strongest study design. Meta-analysis of RCTs with 388 participants.
- Human research volume. 1 human study, 388 participants in total.
- What was measured. Human studies measured surrogate biomarkers only. A change in a marker is not by itself a demonstrated health benefit.
- Replication. The supporting result has not been independently replicated in humans.
Limitations. Trials were small and short, and dosing varied widely; the diabetic-population signal deserves its own, better trials.
| Study | Design | Population | Finding |
|---|---|---|---|
| [2]Effect of resveratrol on glucose control and insulin sensitivity: a meta-analysi…The American journal of clinical nutrition · 2014 · PMID 24695890 | Meta-analysis of RCTsHuman | 388 participantsMixed population | Found no effectMeta-analysis of 11 RCTs: no significant effect on glycaemic measures in non-diabetic participants; benefit signal confined to diabetes. |
Human evidence
2 studies in people.
- [1]Prospective cohort · 783 participants
- [2]Meta-analysis of RCTs · 388 participants
Animal and laboratory evidence
Shown separately, and never used to support a human claim.
No preclinical study is currently linked on this page.
Before anything else
Safety and interactions
Well tolerated at commonly sold doses in trials; very high doses cause gastrointestinal upset, and bioavailability is poor. Interacts with some medicines via CYP enzymes — worth a pharmacist conversation if on regular medication.
The ledger
Grade history
22 August 2026
First published appraisal of this claim. Study links added: PMID 24695890.
22 August 2026
First published appraisal of this claim. Study links added: PMID 24819981.
22 August 2026
First published appraisal of this claim.
Falsifiability
What would change our view
Randomised evidence of hard-outcome benefit in any non-diabetic population, or replication of lifespan effects in normally fed mammals — the NIA's Interventions Testing Program found none.
Check everything
Sources
Every citation links to its PubMed record. Bibliographic details are retrieved from PubMed, not written by us.
- [1]Resveratrol levels and all-cause mortality in older community-dwelling adults Semba RD et al.. JAMA internal medicine. 2014. PMID 24819981 · doi:10.1001/jamainternmed.2014.1582
- [2]Effect of resveratrol on glucose control and insulin sensitivity: a meta-analysis of 11 randomized controlled trials Liu K et al.. The American journal of clinical nutrition. 2014. PMID 24695890 · doi:10.3945/ajcn.113.082024