Sulforaphane
The most potent natural Nrf2 activator known — switches on the body's master detoxification and antioxidant defence program. Derived from broccoli sprouts.
Strong mechanism evidence (Nrf2 activation, detox enzyme upregulation). Moderate human evidence: improved liver detoxification, reduced airway inflammation, lowered oxidative stress markers, modest blood pressure reduction, and an autism trial showing symptom improvement (Singh et al.). Cancer prevention is plausible but hard to prove. Effects: 2–8 weeks.
Sulforaphane is an isothiocyanate produced when you chew or chop cruciferous vegetables — particularly broccoli sprouts, which contain 10–100x more of its precursor (glucoraphanin) than mature broccoli. It activates Nrf2 (Nuclear Factor Erythroid 2), the master switch for the body's Phase II detoxification enzymes, antioxidant defences, and anti-inflammatory pathways. Effects are broad: improved detoxification of carcinogens, reduced oxidative stress, modulation of inflammation, and potential anti-cancer effects (particularly against breast, prostate, and bladder cancers). Sulforaphane is one of the most-studied phytochemicals in cancer prevention research — most prominently championed by Dr. Jed Fahey at Johns Hopkins.
- Form
- Broccoli sprout extract standardised to active sulforaphane (BroccoMax, Avmacol). Fresh broccoli sprouts (3–7 days old) — the original source, can grow at home cheaply. Sulforaphane + myrosinase enzyme products (without the enzyme, glucoraphanin doesn't convert efficiently).
- Dose
- 10–40 mg/day of active sulforaphane from extracts. Broccoli sprouts: ~100 g (1/2 cup) daily provides therapeutic doses.
- Timing
- Anytime. With food generally fine. Heat destroys sulforaphane — eat sprouts raw or steam briefly.
- Schedule
- Daily.
- Side effects
- Generally well-tolerated. Mild GI upset, gas (from cruciferous compounds). Body / breath odor in some.
- Interactions
- Acetaminophen — sulforaphane induces enzymes that may alter metabolism. Anticoagulants (broccoli is K-rich — caution if eating large amounts of sprouts on warfarin).
- Contraindications
- Hypothyroidism (raw cruciferous in very large amounts can be goitrogenic — cooking neutralises this; supplements are generally fine at standard doses). Active malabsorption.
- Lab markers
- Not standard. Functional / research markers: GSH (glutathione), 8-OHdG, urinary sulforaphane metabolites.
- Food sources
- Broccoli sprouts (extraordinary concentration), broccoli, brussels sprouts, cauliflower, kale, cabbage, bok choy, watercress, mustard greens, daikon radish. Chewing thoroughly activates the conversion enzyme — bolting them down whole reduces yield.
Pairs with
Glucoraphanin + myrosinase — needed together for conversion. Curcumin, quercetin, EGCG (polyphenol Nrf2 stack). DIM, I3C (synergistic estrogen metabolism support).
within Polyphenols & antioxidants