by Linda Sparrow and Craig Weatherby
Somehow, people have long sensed that plant foods were good for them. And for decades, parents have pressured kids to eat broccoli, without quite knowing why.
Starting in the late 1960’s, population studies began linking diets high in fruits and vegetables to reduced cancer and heart disease rates.
Broccoli’s long been the butt of jokes… but it’s also been the focus of efforts to verify any possible health benefits of green vegetables… and identify the compounds responsible.
About 30 years ago, research began providing hints that broccoli and other cruciferous vegetables might possess special cancer-prevention potential.
|Don’t overcook your crucifers|
Boiling broccoli and other cruciferous vegetables for more than 30 minutes greatly reduces their anti-cancer powers, because their sulforaphane and other beneficial glucosinolate compounds end up in the water.
Instead, steam, sauté, or microwave them until just tender enough to enjoy.
No significant loss of glucosinolate compounds occurs after steaming cruciferous vegetables up to 20 minutes, microwave cooking them for up to 3 minutes, and stir-frying them for up to 5 minutes (Song L, Thornalley PJ 2007; WMS 2007).
The cruciferous vegetables include broccoli, cabbage, kale, chard, collards, kohlrabi, Brussels sprouts, turnip, rutabaga, bok choy, and cauliflower ("Cruciferous" is the common name for members of the Brassicaceae family, which also encompasses mustard seeds and greens and wasabi).
The members of this vegetable family are rich in carotenes, glucosinolates, and other compounds believed responsible for a variety of health benefits.
Their probable benefits include antioxidant effects, healthier intestinal flora, enhanced clearance of toxins and carcinogens, and reduced risks of cancer and cardiovascular disease (Vasanthi HR et al. 2009).
New findings add artery health to broccoli’s benefits
The results of a study from Imperial College London (ICL), suggests that broccoli may protect critical areas of our arteries from disease by boosting a natural defense mechanism (Zakkar M et al. 2009).
The new findings reveal a previously unknown effect of sulforaphane—a chemical that belongs to a group of compounds called glucosinolates, which are credited with some of the presumed anti-cancer properties of broccoli and other cruciferous vegetables.
The ICL team reports that sulforaphane appears to activate a protein called Nrf2, found in arteries.
Why does this matter?
Arteries don’t clog in a uniform way. Bends and branches of blood vessels, where blood flow is disrupted, can be sluggish and are more prone to the build-up of fatty plaques, causing the condition known as atherosclerosis, which can lead to angina, heart attack, and stroke.
“We found that the innermost layer of cells at branches and bends of arteries lack the active form of Nrf2, which may explain why they are prone to inflammation and disease,” explained study leader Dr Paul Evans of ICL’s National Heart and Lung Institute (BHF 2009).
As Dr. Evans said, “Treatment with the natural [broccoli] compound sulforaphane reduced inflammation at the high-risk areas by ‘switching on’ Nrf2” (BHF 2009).
By switching on the Nrf2 protein, sulforaphane may enhance arterial cells’ ability to keep from becoming inflamed.
The researchers believe that this will help these artery regions remain healthy, or even reduce the progression of existing artery disease.
Given the fact that cardiovascular disease is America’s number one killer, these findings imply that broccoli and other cruciferous vegetables may hold greater preventive health potential than we thought.
- British Heart Foundation (BHF). Research reveals a broccoli boost for arteries. September 5, 2009. Accessed at http://www.bhf.org.uk/default.aspx?page=10400
- Song L, Thornalley PJ. Effect of storage, processing and cooking on glucosinolate content of Brassica vegetables. Food Chem Toxicol. 2007 Feb;45(2):216-24. Epub 2006 Aug 30.
- Vasanthi HR, Mukherjee S, Das DK. Potential health benefits of broccoli – a chemico-biological overview. Mini-Reviews in Medicinal Chemistry Journal, 2009 June 9 (6):749-59.
- Warwick Medical School (WMS). Research Says Boiling Broccoli Ruins Its Anti Cancer Properties. May 15, 2007. Accessed at http://www2.warwick.ac.uk/newsandevents/pressreleases/research_says_boiling/
- Zakkar M, Van der Heiden K, Luong LA, Chaudhury H, Cuhlmann S, Hamdulav SS, Krams R, Edirisinghe I, Rahman I, Carlsen h, Haskard DO, Mason JC, Evans PC. Activation of Nrf2 in endothelial cells protects arteries from exhibiting a proinflammatory state. Arteriosclerosis Thrombosis and Vascular Biology. 2009 Sept; doi:10.1161/ATVBAHA.109.193375