Resveratrol

Medicine Atlas · Food & Nutraceuticals · Stilbenoid Polyphenol · SIRT1 Activator

Source: Grape skin/seeds, red wine, Japanese knotweed, blueberries, peanuts | Active form: trans-Resveratrol (C₁₄H₁₂O₃, MW 228.2 Da) | Category: Stilbenoid polyphenol · Phytoalexin · Phytoestrogen · Nutraceutical

Resveratrol (trans-3,5,4'-trihydroxystilbene) is a phytoalexin produced by plants under stress — characterised by two phenolic rings connected by a trans-ethylene bridge. Primary mechanism: allosteric SIRT1 (Sirtuin-1, NAD⁺-dependent deacetylase) activation → deacetylation of PGC-1α (mitochondrial biogenesis), RelA/p65 (↓NF-κB transcriptional activity), and FOXO3a (antioxidant gene expression). AMPK activation (via Complex I inhibition) provides upstream SIRT1 amplification. Phytoestrogenic activity (weak ER-α/β binding, ERβ-selective). The French Paradox hypothesis linking red wine resveratrol to cardiovascular protection remains controversial. Critical limitation: despite ~70% intestinal absorption, >99% is rapidly glucuronidated/sulfated → <1% systemic free resveratrol. Clinical evidence is Low for most indications; no large Phase III trial demonstrating outcome benefit. Most promising indications: metabolic syndrome, NAFLD, type 2 diabetes biomarker improvements at 150–500 mg/day.

resveratrol trans-resveratrol trans-3,5,4'-trihydroxystilbene 3,5,4'-stilbenetriol Veri-te grape polyphenol

Overview

Resveratrol (trans-3,5,4'-trihydroxystilbene, C₁₄H₁₂O₃, MW 228.2 Da) is a stilbenoid polyphenol produced by plants as a phytoalexin — a stress-response compound synthesised in response to pathogen attack, UV irradiation, drought, and mechanical injury. The trans isomer is the biologically predominant and more stable form. Primary dietary sources include grape skin (50–100 µg/g fresh weight, concentrated in red and purple varieties), red wine (0.1–14.3 mg/L, highly variable by style and vintage), blueberries and bilberries (16–100 µg/g), peanuts (0.02–1.79 µg/g), and Japanese knotweed (Fallopia japonica) — which at up to 0.5% dry weight is the primary botanical source for commercial supplements.

The French Paradox — relatively low cardiovascular mortality in France despite high saturated fat intake — was proposed in 1992 (Renaud and de Lorgeril) to partly reflect resveratrol in red wine. This hypothesis drove enormous research interest but remains controversial: alcohol itself, overall dietary patterns (Mediterranean diet elements), reporting biases, and confounding lifestyle factors are likely major contributors. The xenohormesis hypothesis (Howitz and Sinclair, 2004) provides elegant evolutionary rationale — stressed plants signal environmental adversity to herbivores via resveratrol, activating conserved longevity-promoting stress responses — but is difficult to test directly in humans.

The bioavailability paradox is central to interpreting resveratrol's clinical relevance: while ~70% of an oral dose is absorbed from the intestine (high absorption), >99% is rapidly converted by UGT1A1, UGT1A6, and SULT1A1 to resveratrol glucuronide and sulfate conjugates before reaching systemic circulation. Free resveratrol bioavailability is <1%; plasma free concentrations after 25 mg are ≈5–10 ng/mL (t₁/₂ ~1–3 h), while most in vitro mechanistic studies use 1–100 µM — a 100–1000-fold concentration gap. Whether resveratrol conjugates are partially active and whether enterohepatic recycling and microbiome metabolism compensate is an open question.

Mechanism of Action

SIRT1 / AMPK / NF-κB — Central Signalling Axes

  Resveratrol
       │
       ├──────────────────────────────────────────────────────────────────────┐
       │  SIRT1 allosteric activation                                         │  Complex I inhibition (high conc.)
       │  (STAC-binding domain; enhanced substrate affinity)                  │  → ↑AMP/ATP → AMPK activation (LKB1)
       ▼                                                                      ▼
  SIRT1 (NAD⁺-dependent deacetylase) active                           AMPK activated
       │                                                                      │
       ├── PGC-1α deacetylation ──► PGC-1α active                           ↑NAMPT → ↑NAD⁺
       │     │                                                                │
       │     ▼                                                        Positive feedback loop ↑SIRT1
       │   NRF1, TFAM: ↑Mitochondrial biogenesis                             │
       │   PPARα: ↑Fatty acid oxidation                              AMPK also:
       │   OXPHOS gene ↑ (caloric restriction mimicry)               ↓ACC → ↑FA oxidation
       │                                                              ↓mTOR → ↑autophagy
       ├── RelA/p65 deacetylation (Lys-310) ──► ↓NF-κB transcriptional activity
       │     │
       │     ▼
       │   ↓TNF-α, ↓IL-6, ↓IL-8, ↓MCP-1, ↓VCAM-1, ↓ICAM-1
       │
       ├── FOXO3a deacetylation ──► FOXO3a active ──► ↑Catalase, ↑SOD2, ↑GADD45
       │                                                ↑Autophagy
       │
       └── p53 deacetylation (Lys-382) ──► Complex p53 regulation (context-dependent)

SIRT1 allosteric activation: Resveratrol binds the N-terminal STAC-binding domain of SIRT1, enhancing substrate binding affinity and deacetylase catalytic rate — the key primary mechanism. Early concerns about a fluorophore-dependent assay artefact have been partially resolved; SIRT1 activation with native substrates is confirmed in cellular systems.
PGC-1α deacetylation → mitochondrial biogenesis: Activated SIRT1 deacetylates PGC-1α, the master co-activator of mitochondrial biogenesis and fatty acid oxidation. This drives NRF1/TFAM-mediated mitochondrial gene expression and PPARα-driven fatty acid oxidation — phenocopying aspects of caloric restriction in animal models.
RelA/p65 deacetylation → NF-κB suppression: SIRT1 deacetylates RelA/p65 at Lys-310, directly reducing NF-κB transcriptional activity → ↓pro-inflammatory cytokine gene expression (TNF-α, IL-6, IL-8) and ↓endothelial adhesion molecules (VCAM-1, ICAM-1). Resveratrol also independently stabilises IκBα via weak IKKβ inhibition.
AMPK activation → SIRT1 amplification loop: At higher concentrations, resveratrol inhibits mitochondrial Complex I → ↑AMP/ATP → AMPK activation via LKB1 → ↑NAMPT → ↑NAD⁺ → further SIRT1 activation. This SIRT1-AMPK positive feedback loop may be the dominant mechanism at pharmacological supplement doses where direct SIRT1 activation is sub-threshold.

Additional Mechanisms

eNOS upregulation (CV)

SIRT1 deacetylates eNOS at Lys-496/506 → ↑eNOS activity → ↑NO → vasodilation and ↓platelet aggregation; the SIRT1-AMPK-eNOS axis is the key proposed cardiovascular mechanism linking resveratrol to endothelial function

Phytoestrogen (ERα/β)

Weak ER-α and ER-β binding (~10,000-fold lower affinity than 17β-estradiol); ERβ-selective activity potentially anti-proliferative in breast cancer (opposite of ERα effects). Clinical hormonal effect at standard doses is likely minimal given very low affinity

Anti-fibrotic (liver)

SIRT1 activation reduces hepatic stellate cell (HSC) activation and TGF-β-driven collagen deposition; SIRT1/PGC-1α axis reduces hepatic lipid accumulation in NAFLD models; inhibits HSC-myofibroblast transdifferentiation

M2 macrophage polarisation

Resveratrol polarises macrophages toward anti-inflammatory M2 phenotype via SIRT1/PGC-1α metabolic reprogramming → ↑IL-10, ↓TNF-α, ↓IL-6; relevant to adipose tissue inflammation in obesity and foam cell formation in atherosclerosis

Dietary Sources & Supplementation

Food / Supplement Source	Typical Resveratrol Content	Bioavailability	Notes
Red wine (1 glass, ~150 mL)	~0.015–2.1 mg trans-resveratrol	Moderate for free resveratrol; alcohol co-consumption alters metabolism	Highly variable by grape variety, region, and vintage; Pinot Noir and Muscadine typically highest
Red grape juice (150 mL)	~0.1–0.5 mg resveratrol	Moderate	No alcohol — cleaner resveratrol source for those avoiding alcohol; also contains other polyphenols
Blueberries (100 g fresh)	~0.0016–0.01 mg (trace)	Moderate	Minor resveratrol source; valuable for other anthocyanins and polyphenols
Peanuts (100 g roasted)	~0.002–0.18 mg	Moderate	Boiled peanuts contain more than dry-roasted; commercially available peanut butter contains trace amounts
Standard resveratrol supplement (100–500 mg)	100–500 mg trans-resveratrol (from Japanese knotweed)	Low free resveratrol (<1%); conjugates accumulate	Doses far exceed dietary amounts; optimal dose for humans unknown; take with fatty meal for better absorption
Micronised / liposomal resveratrol	50–250 mg per serving	Modestly improved Cmax vs. standard	Particle size reduction ↑dissolution; independent clinical pharmacokinetic validation is limited for most commercial preparations

Clinical Evidence

Study	Design	n	Key Result
Baur et al. Nature 2006 (preclinical)	Mouse study; high-calorie diet + resveratrol 22 mg/kg/day; survival and metabolic endpoints	Murine	↑Survival vs. untreated high-calorie; ↑insulin sensitivity; ↑mitochondrial biogenesis via SIRT1/PGC-1α; phenotypic resemblance to caloric restriction. Landmark but NOT directly translatable — murine dose exceeds human equivalent; mouse metabolism differs substantially.
Timmers et al. Cell Metab 2011	RCT, crossover; 150 mg/day resveratrol vs. placebo; 30 days; healthy obese men	11	↓Metabolic rate; ↑AMPK activity in muscle biopsies; ↑SIRT1 protein; ↑mitochondrial density; ↓plasma TG. Promising mechanistic validation in humans — but small (n=11) and short-term.
Diabetes/metabolic meta-analysis (Liu 2014, AJCN)	Meta-analysis of 9 RCTs; resveratrol 150–3,000 mg/day in type 2 diabetes / pre-diabetes	~300 pooled	Fasting glucose: −5.9 mg/dL (95% CI −11.2 to −0.5; p=0.04); HOMA-IR: −0.38. Modest but statistically significant. Heterogeneous formulations and doses; many trials n<30. GRADE: Low.
NAFLD (multiple small RCTs)	RCTs; resveratrol 300–500 mg/day; 8–24 wk; NAFLD confirmed by ultrasound	30–100 per trial	Some improvement in ALT, hepatic steatosis grade on ultrasound, and HOMA-IR. Inconsistent across trials. GRADE: Low.
Cognitive ageing (Turner 2015)	RCT; 200 mg/day resveratrol; 26 weeks; postmenopausal women	80	Improved word retention and memory performance vs. placebo; ↑cerebrovascular responsiveness on fMRI. Interesting but single trial, not replicated consistently. GRADE: Low.

The clinical translation gap: Resveratrol has arguably the most compelling preclinical mechanistic story in nutritional biochemistry — SIRT1/AMPK activation genuinely mimicking aspects of caloric restriction in rodents is scientifically well-established. However, the pharmacokinetic barrier (<1% free bioavailability) creates a fundamental challenge: no large, adequately powered Phase III RCT has demonstrated resveratrol benefit on any clinical outcome (mortality, cardiovascular events, diabetes incidence). The CALERIE-2 caloric restriction trial showed that actual caloric restriction benefits in humans are modest and may not be replicated by SIRT1 activators alone. The SRT-501 (high-bioavailability formulation) multiple myeloma trial was halted due to renal adverse events. Resveratrol remains genuinely interesting scientifically but clinical recommendations await higher-quality evidence.

Safety & Interactions

Generally well-tolerated at ≤1 g/day: Most RCTs report good tolerability at 150–1000 mg/day in short-term studies. GI adverse effects (nausea, diarrhoea, abdominal discomfort) emerge dose-dependently at >2.5 g/day. High-dose SRT-501 formulation caused renal adverse events in a multiple myeloma trial — caution at doses >2.5 g/day.
Warfarin — CYP2C9 inhibition: Resveratrol inhibits CYP2C9 in vitro → potential ↑warfarin exposure and elevated INR. Clinically relevant at supplement doses ≥500 mg/day. Monitor INR in anticoagulated patients.
Statins — CYP3A4 inhibition: Resveratrol inhibits CYP3A4 → potentially ↑simvastatin, atorvastatin, lovastatin AUC → myopathy risk. Use caution with combination at high resveratrol doses (>500 mg/day); pravastatin and rosuvastatin are safer alternatives (not CYP3A4 substrates).
Antiplatelet effects — additive bleeding risk: Resveratrol inhibits COX-1 (weak, high-concentration) → ↓TXA₂ → antiplatelet effect; SIRT1/eNOS activation → ↑NO → vasodilation and ↓platelet adhesion. Additive with aspirin, clopidogrel, heparin, and NSAIDs. Caution pre-operatively.
Cyclosporine — CYP3A4/P-gp inhibition: ↑Cyclosporine AUC → nephrotoxicity and toxicity risk. Avoid in transplant patients on cyclosporine without close monitoring.
Phytoestrogen considerations: Weak ERβ-selective binding; theoretical concerns in hormone-sensitive conditions (estrogen receptor-positive breast cancer, active hormonal therapy). Clinical evidence for significant hormonal effect at standard doses (<500 mg/day) is limited, but caution is prudent in ER+ breast cancer patients without oncologist guidance.
No established therapeutic dose: There is no regulatory-approved dosing for any indication; typical commercial supplements provide 100–500 mg/day. The optimal dose for human health, if any, remains unknown pending adequately powered RCTs.

Connections

Modulates Cardiovascular System Modulates NF-κB (entry pending) Modulates Macrophage (entry pending) Modulates Liver (entry pending) Related Curcumin Related Quercetin

References

Baur JA, Pearson KJ, Price NL, et al. Resveratrol improves health and survival of mice on a high-calorie diet. Nature. 2006;444(7117):337-342. doi:10.1038/nature05354 · PubMed 17086191
Walle T, Hsieh F, DeLegge MH, Oatis JE Jr, Walle UK. High absorption but very low bioavailability of oral resveratrol in humans. Drug Metab Dispos. 2004;32(12):1377-82. doi:10.1124/dmd.104.000885 · PubMed 15333514
Timmers S, Konings E, Bilet L, et al. Calorie restriction-like effects of 30 days of resveratrol supplementation on energy metabolism and metabolic profile in obese humans. Cell Metab. 2011;14(5):612-22. doi:10.1016/j.cmet.2011.10.002 · PubMed 22055504
Liu K, Zhou R, Wang B, Mi MT. Effect of resveratrol on glucose control and insulin sensitivity: a meta-analysis of 11 randomized controlled trials. Am J Clin Nutr. 2014;99(6):1510-9. doi:10.3945/ajcn.113.082024 · PubMed 24695888
Renaud S, de Lorgeril M. Wine, alcohol, platelets, and the French paradox for coronary heart disease. Lancet. 1992;339(8808):1523-6. doi:10.1016/0140-6736(92)91277-F · PubMed 1351198
Berg JM, Tymoczko JL, Stryer L. Biochemistry. 9th ed. W.H. Freeman; 2019. ISBN 131911467X.