Resveratrol for Preventive Purposes in Healthy Adults
Resveratrol cannot be recommended for preventive purposes in generally healthy adults, as current evidence shows inconsistent effects, poor bioavailability, and no established safe or effective dosing regimen for disease prevention. 1
Guideline-Based Position
The ESPEN (European Society for Clinical Nutrition and Metabolism) guidelines explicitly state that antioxidants including resveratrol cannot be recommended until further data regarding their efficacy are available, achieving 100% consensus among experts. 1 This recommendation was made in the context of liver disease (NAFLD/NASH), but the underlying evidence reveals fundamental problems with resveratrol supplementation that extend to general preventive use.
Evidence of Inconsistent and Contradictory Effects
The available clinical trial data demonstrates highly variable and often contradictory results:
High-dose resveratrol (3000 mg daily for 8 weeks) showed no beneficial effects on insulin resistance, steatosis, abdominal fat distribution, plasma lipids, or antioxidant activity in overweight/obese men, and actually increased liver enzymes (ALT and AST) significantly, suggesting potential harm. 1
Lower doses (300 mg daily, given as 2 × 150 mg) for 3 months showed improvements in liver enzymes, cholesterol, and insulin resistance in normal-weight men with fatty liver disease. 1
Moderate doses (500 mg daily) combined with lifestyle intervention showed some benefit for liver inflammation and steatosis in overweight patients, though this study was published in duplicate, raising quality concerns. 1
Critical Limitations for Preventive Use
Bioavailability remains the fundamental barrier to resveratrol's clinical utility. Despite promising preclinical data showing antioxidant, anti-inflammatory, cardioprotective, and neuroprotective effects in laboratory settings, resveratrol exhibits poor absorption and extensive first-pass metabolism in humans. 2, 3, 4, 5 This creates a significant disconnect between in vitro concentrations that show benefit and achievable plasma levels in living humans. 3
No standardized dosing exists for healthy adults seeking preventive benefits. The studied doses range from 150 mg to 3000 mg daily, with no clear dose-response relationship and contradictory outcomes at different doses. 1
Safety Concerns
While generally considered safe with mild to moderate gastrointestinal side effects, the elevation of liver enzymes at high doses (3000 mg daily) raises concerns about potential hepatotoxicity. 1, 3 For a healthy adult taking supplements preventively, any risk of liver injury—even if uncommon—outweighs unproven benefits.
Why Resveratrol Likely Won't Work as Monotherapy
Research suggests resveratrol requires synergism with other dietary factors and is unlikely to be effective as a standalone preventive agent due to its poor bioavailability and extensive biotransformation. 2 The polyphenol's benefits may be better obtained through whole food sources (grapes, berries, red wine in moderation) rather than isolated supplementation. 2, 6, 3, 4, 5
Clinical Bottom Line
For a generally healthy adult considering preventive supplementation, resveratrol should not be recommended. The evidence base is insufficient, dosing is not established, bioavailability is poor, and potential risks (including liver enzyme elevation) exist without proven benefit for mortality, morbidity, or quality of life outcomes in healthy populations. 1
If patients insist on supplementation despite counseling, advise them that no safe or effective dose has been established for preventive purposes, and that dietary sources of resveratrol through a balanced diet rich in fruits and berries may be preferable to isolated supplements. 2, 3, 4, 5