The transcription factor Nrf2 maintains cellular redox balance, in part, by regulating the biosynthesis and regeneration of glutathione and thioredoxin, the body’s principal endogenous antioxidants, and by controlling the production of reactive oxygen species in the mitochondria, the cell’s energy factories.31 Activation of Nrf2 induces the genetic expression of a battery of cytoprotective antioxidant enzymes and proteins while protecting against mitochondrial dysfunction and promoting mitochondrial biogenesis.32
Sulforaphane, a sulfur-containing compound found in broccoli, cauliflower, and other cruciferous vegetables, has been intensely studied as a potent inducer of Nrf2.33-41 Its lipophilic (fat-loving) nature and low molecular weight provide sulforaphane with higher bioavailability than the phenol-based nutrients that also activate Nrf2.42 Compared to the polyphenols curcumin, silibinin, and resveratrol, sulforaphane has been found to more potently activate Nrf2, causing strong up-regulation of endogenous antioxidant enzymes and inducing the process of autophagy.43 Because the Nrf2 cell-defense pathway protects against disorders caused by long-term exposure to reactive oxygen species, sulforaphane plays an important role in the body’s defense against chronic disease. It is found to be a promising chemoprevention agent against a variety of cancers, cardiovascular disease, neurodegenerative disease, immunological disorders, and diabetic nephropathy.44;45
Sulforaphane belongs to a group of compounds called isothiocyanates (ITCs), and it is a nutrient new to the Blended Standard. Information on optimal daily intake is very sparse; however, Hecht and coworkers46 have shown that consumption of average servings of vegetables can release tens of milligrams of ITCs. The principal sources of sulforaphane are broccoli, cabbage and Brussels sprouts, with an average glucoraphanin content (glucoraphanin is a precursor of sulforaphane) of 50 mg/serving.47 This would provide approximately 20 mg of sulforaphane/serving. Consumption of five or more servings of cruciferous vegetables per week has been associated with significant reductions in cancer risk.47 Consequently, NutriSearch has established a suggested intake for sulforaphane at 20 mg/day.
NutriSearch Corporation is a Canadian company specializing in nutrition and health research, focussed primarily on multiple vitamin and mineral supplementation.
Our main product is the NutriSearch Comparative Guide to Nutritional Supplements™, which examines current research on the health benefits of supplementation for prevention of degenerative disease. The guide also includes comparisons of broad-spectrum supplements available in various markets around the world, is available in various regions. The guide for the Americas includes product comparisons from Canada, Colombia, México, and the United States. We also publish a guide for Australia and New Zealand.
NutriSearch is also available as a consultant to nutritional supplement manufacturers wanting to improve their supplements.