Glucoraphanin, also known as sulforaphane glucosinolate (SGS), is present in high levels in broccoli sprouts. Testing the effects of the sprouts on an animal model for hypertension in humans, researchers found evidence of increased tissue antioxidant defense mechanisms, lowered inflammatory response and improved cardiovascular health.
"Nearly all the studies to date on sulforaphane, glucoraphanin and broccoli sprouts have focused on the protective effects of these substances against cancer. This study is the first to show that broccoli sprouts rich in these compounds raise the antioxidant and thereby the anti-inflammatory capacities of cells, and can profoundly affect the cardiovascular system and correct major dysfunctions such as hypertension and stroke," said study leader Bernhard H.J. Juurlink, from the University of Saskatchewan, Canada.
The findings, published in the 4 May issue of the Proceedings of the National Academy of Sciences, (or online at 10.1073/pnas.0402004101) suggest that even a modest change in diet has the potential to have a major impact on health and reduce health care costs significantly.
Over a 14-week period, Juurlink and colleagues fed either broccoli sprouts that were either rich in glucoraphanin or depleted of glucoraphanin to rats that were prone to high blood pressure and stroke. Rats fed a glucoraphanin-rich diet exhibited increased tissue antioxidant defense mechanisms, lowered inflammatory response and improved cardiovascular health as demonstrated by decreased blood pressure and decreased inflammation in the heart, arteries and kidneys.
"Increasing evidence suggests that antioxidant defense mechanisms may be boosted by specific chemicals known as Phase 2 protein inducers, some of which can be found in certain foods," explained Juurlink.
Glucoraphanin or SGS plays a role in boosting the body's natural Phase 2 enzyme antioxidant defense systems and functions as a powerful indirect antioxidant detoxifying carcinogens before they can damage cells. Typical direct antioxidant molecules, such as vitamins C and E, scavenge one free radical or other oxidant molecule at a time. Once a direct antioxidant molecule binds to a free radical molecule, rendering it harmless, the antioxidant is consumed and is no longer active.
The indirect antioxidant SGS works as a catalyst. It does not neutralize free radicals directly, but rather boosts the body's own antioxidant systems (including Phase 2 detoxification enzymes) that exerts ongoing and prolonged antioxidant activity. This is a broad spectrum of activity, cycling over and over, removing many free radicals.
"Although more research needs to be done to fully establish the link between SGS and improved heart health, the findings are encouraging," said Juurlink.
Ten papers on SGS have already been published so far this year. Two studies presented at the annual meeting of the American Association for Cancer Research in March showed that sulforaphane inhibited the growth of human prostate cancer cells, and another showed it stopped the growth of colon cancer cells.
Several recent studies also showed that sulforaphane kills Helicobacter pylori, the bacteria that cause stomach ulcers and can lead to stomach cancer.