Sulforaphane
An isothiocyanate from broccoli sprouts and the most potent natural activator of the NRF2 antioxidant-response pathway. Human trials support benefits for detoxification enzymes and some metabolic and inflammatory markers; it is a well-studied phytochemical, though direct aging-outcome data are absent.
01 Overview
Sulforaphane is an isothiocyanate generated when the glucosinolate glucoraphanin in cruciferous vegetables (richest in broccoli sprouts) is hydrolysed by the enzyme myrosinase. It is the archetypal NRF2 activator, switching on a broad battery of cytoprotective, antioxidant, and phase-II detoxification genes, a pathway central to cellular stress resistance and implicated in aging.
Human studies show sulforaphane upregulates detoxification enzymes and can accelerate excretion of airborne pollutants, and smaller trials report benefits in insulin resistance, blood pressure, and inflammatory or autism-related endpoints. Bioavailability depends heavily on formulation and on whether active myrosinase is present. There is no human evidence for a lifespan effect, but its NRF2 mechanism makes it a mainstay geroprotective supplement.
02 Mechanism
Modifies KEAP1 cysteines to release NRF2, which translocates to the nucleus and induces antioxidant-response-element genes (glutathione synthesis, phase-II detox enzymes, NQO1, HO-1), boosting cellular stress resistance.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common (equivalent) | 10–40 mg/day | Oral | Doses vary widely by formulation; broccoli-sprout extracts often standardised to sulforaphane/glucoraphanin. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| NRF2 activation / phase-II detox inductionReliably activates NRF2 and increases detoxification-enzyme activity and pollutant excretion in humans. | robust enzyme induction | Clinical | |
| Improved metabolic / inflammatory markersSome trials show reduced fasting glucose in type 2 diabetes and lower inflammatory markers. | modest | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| GI discomfort / gasBloating, gas, or mild stomach upset can occur, especially with sprout-based products. | Mild | Uncommon | Clinical | |
| Thyroid consideration at very high intakeVery high cruciferous/glucosinolate intake is theoretically goitrogenic, particularly with iodine deficiency. | Mild | Rare / theoretical | Preclinical |