Discovery may help scientists boost broccoli's cancer-fighting power

October 22, 2010

A University of Illinois study has shown for the first time that sulforaphane, the powerful cancer-fighting agent in broccoli, can be released from its parent compound by bacteria in the lower gut and absorbed into the body.

"This discovery raises the possibility that we will be able to enhance the activity of these in the colon, increasing broccoli's cancer-preventive power," said Elizabeth Jeffery, a U of I professor of human nutrition.

"It's also comforting because many people overcook their broccoli, unwittingly destroying the plant enzyme that gives us sulforaphane. Now we know the microbiota in our can salvage some of this important cancer-preventive agent even if that happens," she said.

Although scientists had long theorized that the intestinal microbiota could perform this trick, no one knew it for certain.

Now Jeffery and U of I colleagues Michael Miller and Ren-Hau Lai have proved it by injecting glucoraphanin, the parent compound for sulforaphane, into the ligated lower gut of rats and demonstrating that sulforaphane is present in blood from the mesenteric vein, which flows from the gut to the liver.

"The presence of sulforaphane in measurable amounts shows that it's being converted in the lower intestine and is available for absorption in the body," Jeffery said.

The cecum, the part of the rat's lower gut into which the scientists infused the glucoraphanin, houses bacteria that aid in digestion and metabolism, similar to the human colon.

According to Jeffery, sulforaphane is an extremely potent cancer-fighting agent. "The amount that you get in three to five servings a week—that's less than one daily serving of broccoli—is enough to have an anti-cancer effect. With many of the other bioactive foods you hear about, vast amounts are required for a measurable outcome."

Sulforaphane also has anti-inflammatory properties, which are interesting to scientists for their ability to counter the effects of many of the chronic diseases that accompany obesity and aging.

Miller suggests two ways bacteria in the colon could be manipulated to get a boost out of broccoli. "One way might be to feed the desirable bacteria with prebiotics like fiber to encourage their proliferation. Another way would be to use a probiotic approach—combining, say, broccoli with a yogurt sauce that contains the hydrolyzing bacteria, and in that way boosting your cancer protection."

Doesn't sound particularly appealing? Bacteria aren't always bad news, said Jeffery.

"One of the things we don't think about very much is the enormous amount of benefit we experience when a healthy community of bacteria colonizes the lower intestine," she said.

"We humans have a symbiotic relationship with countless hungry microbes that metabolize vitamins and other bioactive components of food. Now we can see another exciting example of their activity with the role they play in delivering from ," she added.

More information: The study is the cover story of the November 2010 issue of the new journal Food & Function (Vol. 1, pp. 162-167) and is available online pre-publication at pubs.rsc.org/en/Journals/JournalIssues/FO

Related Stories

Recommended for you

Moderate coffee drinking 'more likely to benefit health than to harm it', say experts

November 22, 2017
Drinking coffee is "more likely to benefit health than to harm it" for a range of health outcomes, say researchers in The BMJ today.

When traveling on public transport, you may want to cover your ears

November 22, 2017
The noise levels commuters are exposed to while using public transport or while biking, could induce hearing loss if experienced repeatedly and over long periods of time, according to a study published in the open access ...

Different types of alcohol elicit different emotional responses

November 22, 2017
Different types of alcohol elicit different emotional responses, but spirits are most frequently associated with feelings of aggression, suggests research published in the online journal BMJ Open.

Air pollution linked to poorer quality sperm

November 22, 2017
Air pollution, particularly levels of fine particulate matter (PM2.5), is associated with poorer quality sperm, suggests research published online in Occupational & Environmental Medicine.

Sunrise and sunset guide daily activities of city-dwellers

November 21, 2017
Despite artificial lightning and social conventions, the dynamics of daylight still influence the daily activities of people living in modern, urban environments, according to new research published in PLOS Computational ...

Older men need more protein to maintain muscles

November 21, 2017
The amount of protein recommended by international guidelines is not sufficient to maintain muscle size and strength in older men, according to a new study.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.