The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 11 No. 7 • December 2008
Absorption of Sulforaphane in Humans Higher After
Consuming Raw As Opposed to Cooked Broccoli
One of the important health-promoting constituents of broccoli, cauliflower, and other cruciferous vegetables is the isothiocyanate, sulforaphane. Animal studies have shown sulforaphane to be a potent anti-carcinogen that is proposed to work by inhibiting carcinogen-activating phase 1 biotransformation enzymes, inducing phase II detoxification enzymes, anti-inflammation, and induction of apoptosis (programmed cell death).
A new study reports that, in eight men who ate 200 grams of crushed broccoli, either raw or cooked, with a warm meal in a randomized free-living open cross-over trial, sulforaphane was found in significantly greater amounts in the blood and urine of those who ate the raw as compared to the cooked broccoli. The bioavailability of sulforaphane was reported to be 37% after raw broccoli consumption as compared to 3.4% after cooked broccoli consumption. The absorption of sulforaphane was also delayed after eating cooked broccoli, with peak plasma levels for sulforaphane reached at 6 hours for cooked versus 1.6 hours for raw broccoli.
Phase II Detoxification Pathway to Better Health
The induction of phase II enzymes has been reported in many animal studies to promote important health-protective effects (for example, anti-inflammation, suppression of neuron loss in a fruit fly model of Parkinson’s disease, hypolipidemic effects of green tea, silibinin in cancer chemoprevention, protection against chemical carcinogenesis by curcumin, and healthier aging. Phase II enzyme inducers include, in addition to those found in cruciferous vegetables, black tea, green tea, green onion, BHT, and anthocyanins (the blue and purple colored substances found in, for example, berries).
1. Vermeulen et al. Bioavailability and kinetics of sulforaphane in humans after consumption of cooked versus raw broccoli. J Agric Food Chem 56:10505-10509 (2008)
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