Sprouts plus supplements could boost broccoli’s anti-cancer ability

Researchers of the University of Illinois say a combination of broccoli and broccoli sprouts may boost the vegetable’s ability to protect against cancer as much as twofold.

"Broccoli, prepared correctly, is an extremely potent cancer-fighting agent—three to five servings a week are enough to have an effect,” says Elizabeth Jeffery.

“To get broccoli's benefits, though, the enzyme myrosinase has to be present; if it's not there, sulforaphane, broccoli's cancer-preventive and anti-inflammatory component, doesn't form."

Overcooking the broccoli would destroy myrosinase and the idea of using broccoli powder supplements in food to boost nutrition may be wrong, because the supplements do not contain the necessary enzyme, according to the study.

"There is a way to boost that powder's effectiveness, though. Broccoli sprouts contain myrosinase in abundance. And broccoli powder often contains the precursor to sulforaphane without the enzyme that would boost its healthful benefits," said Jenna Cramer, co-author of the study.

The researchers hypothesized that myrosinase from the sprouts help enhance sulforaphane formation and absorption from the broccoli powder if they were eaten together.

In order to corroborate their hypothesis, the researchers recruited four volunteers who ate meals that contained broccoli sprouts alone, broccoli powder alone, or a combination of the two.

After three hours, the researchers accessed levels of sulforaphane metabolites in the men’s blood and urine, which are associated with cancer prevention, and found a definite synergistic effect was noted between the powder and the sprouts.

"There was almost a twofold increase in sulforaphane absorption when sprouts and powder were eaten together. It changed the way the subjects metabolized the powder. We saw plasma and urine metabolites much earlier and at much higher levels than when either was eaten alone," Jeffery said.

The results showed sulforaphane was produced from both the sprouts and precursor present in the broccoli.  Other foods that contain sulforaphane such as mustard, radishes, arugula and wasabi could also be teamed with broccoli to increase its benefits.

"To increase the vegetable's benefits, you could sprinkle broccoli sprouts on your broccoli or make a mustard sauce to serve with broccoli," she added.

Overcooking will kill the important enzyme myrosinase, so steaming for two to four minutes is the best way to hold the broccoli’s nutrients, Jeffery suggested.

This vegetable is thought to be linked to reduce the risk of developing cancers such as prostate cancer, lung cancer and breast cancer.

And in earlier study, the substances called isothiocyanate in broccoli has also been found to show promise to fight against cancer.

Stephen Lau and editing by Denise Reynolds