U. ILLINOIS (US) — Pairing broccoli with broccoli sprouts may double the vegetable’s anti-cancer qualities, but overcooking it can be the kiss of death for its health benefits.
“Broccoli, prepared correctly, is an extremely potent cancer-fighting agent—three to five servings a week are enough to have an effect,” says Elizabeth Jeffrey, professor of nutrition at the University of Illinois.
“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 broccoli destroys myrosinase, Jeffrey says—and powder supplements often don’t contain it. “Steaming broccoli for two to four minutes is the perfect way to protect both the enzyme and the vegetable’s nutrients.”
The study was published in the journal Nutrition and Cancer.
Jeffrey and Jenna Cramer, co-author of the study, hypothesized that myrosinase from the sprouts would enhance sulforaphane formation and absorption from the broccoli powder if the two were eaten together.
In a small pilot study, they recruited four healthy men who ate meals that contained broccoli sprouts alone, broccoli powder alone, or a combination of the two. The researchers then measured levels of sulforaphane metabolites in the mens’ blood and urine after feeding.
“We were looking at biomarkers—plasma and urine levels—that are associated with cancer prevention,” Cramer says. Three hours after feeding, a definite synergistic effect was noted between the powder and the sprouts.
“We saw 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 says.
This indicates that myrosinase from the broccoli sprouts produced sulforaphane not only from the sprouts but also from the precursor present in the broccoli powder.
Other foods that contain sulforaphane and can be teamed with broccoli to boost its benefits are mustard, radishes, arugula, and wasabi.
Caudill Seed Company funded the research and provided broccoli products.
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