Cruciferous vegetables like broccoli have long been known to contain plant chemicals like indoles that have anti-cancer action. Now a new study confirms that another plant compound found in broccoli—sulforaphane—also has cancer-fighting properties.
The latest study, done by Emily Ho and a team of researchers from the Linus Pauling Institute at Oregon State University, found that sulforaphane—a powerful antioxidant found in abundance in broccoli and other cruciferous vegetables—has the power to selectively target and kill cancer cells, meanwhile leaving normal prostate cells unaffected.
Sulforaphane- which is also a potent antioxidant—apparently inhibits HDAC enzymes (histone deacetylase) which play an important role in whether or not certain genes—like tumor suppressor genes—are “expressed” (activated) or not. HDAC inhibition is a very promising are of cancer treatment and researchers are working on both pharmaceutical and dietary approaches to inhibiting this group of enzymes.
Cancer is characterized by inappropriate cell growth, but HDAC inhibitors can help restore cells to their normal function. Previous studies at Oregon State have demonstrated that the growth of prostate tumors in mice were significantly slowed by diets containing sulforaphane. Lead researcher Emily Ho—an associate professor in the Department of Nutrition and Exercise Science at OSU– told Science Daily, “(Sulforaphane) does appear to be a phytochemical that can selectively kill cancer cells, and that’s always what you look for in cancer therapies”.
And sulforaphane’s cancer-fighting ability doesn’t come solely from its ability to inhibit the HDAC enzymes. As I wrote in “The 150 Healthiest Foods on Earth”, sulforaphane increases the activation of enzymes in the liver which help fight carcinogens. These enzymes- known as phase-2 enzymes—are essential for detoxification and are believed to reduce the risk of prostate cancer. According to research from the Department of Urology at Stanford University published in Cancer Epidemiology Biomarkers and Prevention, sulforaphane is the most potent inducer of phase-2 enzymes of any phytochemical known to date!
Other studies have demonstrated the cancer-fighting power of cruciferous vegetables. In 2007, Victoria Kirsh, PhD., of Cancer Care Ontario in Toronto and her team found that eating fruits and vegetables in general was not associated with decreased prostate cancer risk, but greater consumption of dark green and cruciferous vegetables were. “A possible means to reduce the burden of this disease may be primary prevention through increased consumption of broccoli, cauliflower and possibly spinach”, wrote the authors.
The best news of all is that you don’t have to eat that much broccoli (or broccoli sprouts, which has over 50 times the amount of sulforaphane found in regular mature broccoli) to get cancer-risk-reducing benefit. An earlier study—also by Emily Ho—found that eating some broccoli sprouts on top of a bagel with cream cheese (not recommended!) resulted in HDAC inhibition.
“The compound in broccoli may be one of the strongest anti-cancer fighters we have”, said Ho.
It’s important to remember that the way you cook your broccoli has a lot to do with getting the most cancer-fighting ability out of the vegetable. Broccoli contains an important enzyme of its own, called myrosinase, which has to be present to form sulforaphane. Myrosinase can be destroyed by overcooking their broccoli, so make sure not to do that! Steaming it for 2-4 minutes is absolutely ideal.
You can also up the sulforaphane content of broccoli—or even of broccoli powder or green drink powders that contain it—by simply adding some broccoli sprouts. One study found a strong synergistic effect between broccoli powder and sprouts. The lead author of that study, Elizabeth Jeffrey of the University of Illinois, told Science Daily, “There was almost a twofold increase in sulforaphane absorption when sprouts and powder were eaten together”.
So there you have it. An ordinary inexpensive food with solid research backing its cancer-fighting ability. That’s a whole lot more promising than most of the expensive over-hyped “anti-cancer” products on the market!