Steaming broccoli preserves potential power to fight cancer, study finds

Steaming broccoli preserves potential power to fight cancer: study
Researchers found that boiling, microwaving destroyed enzyme needed to release key compound.

(HealthDay)—The way you prepare broccoli and related vegetables can alter their potentially cancer-fighting powers, new research shows.

Broccoli and other are a good source of sulforaphane, a phytochemical (naturally occurring plant compound) that has shown strong anti-cancer properties in lab studies.

However, the enzyme myrosinase in broccoli is needed for sulforaphane to form. If the myrosinase is destroyed, sulforaphane cannot form.

Researchers compared boiled, microwaved and steamed broccoli, and found that steaming broccoli for up to five minutes was the best way to retain its myrosinase. Boiling and microwaving broccoli for one minute or less destroyed the majority of the enzyme, according to Elizabeth Jeffery, a researcher at University of Illinois at Urbana-Champaign.

Jeffery also found that if you do eat well-cooked broccoli, you can still get sulforaphane to form by adding raw foods containing myrosinase to your meal. Study participants ate a supplement with no active myrosinase. When some of them ate a second food with myrosinase, their blood and urine levels of sulforaphane were significantly higher than those who did not eat the second food with myrosinase.

The findings were presented Thursday at the annual meeting of the American Institute for Cancer Research in Bethesda, Md. Findings presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

"Mustard, radish, arugula, wasabi and other uncooked cruciferous vegetables such as coleslaw all contain myrosinase, and we've seen this can restore the formation of ," Jeffery said in an institute news release.

Previous research has found that:

  • Crushing or chopping garlic, and then waiting 10 to 15 minutes before exposing it to heat allows its inactive compounds to convert into the active, protective phytochemical known as allicin.
  • Cooking tomatoes and other foods that contain lycopene allows our body to more easily absorb the beneficial phytochemical.
  • Boiling vegetables for a long time means you lose water-soluble vitamins, such as vitamin C, folate and niacin that leach into the water.

"As we're learning, food processing isn't just what happens to food before it reaches the grocery shelves," AICR associate director of nutrition programs Alice Bender said in the news release. "This research highlights that what you do in your kitchen can make those fruits and on your plate even more cancer-protective."

More information: The American Cancer Society explains lifestyle choices that can reduce cancer risk.

Related Stories

Maximizing broccoli's cancer-fighting potential

date Oct 16, 2013

Spraying a plant hormone on broccoli—already one of the planet's most nutritious foods—boosts its cancer-fighting potential, and researchers say they have new insights on how that works. They published ...

Recommended for you

Top European beers to show calorie counts

date 8 hours ago

Beer drinkers in Europe will soon be able to find out the calorie count on their drinks after four of the world's biggest brewers said Thursday that they will list the information.

One in four high school seniors now try water pipes

date 13 hours ago

Despite declines in the number of youths who smoke cigarettes, hookah or water pipe use continues to rise among Canadian youth, a new study from the University of Waterloo reports. Published Monday in Cancer Ca ...

User 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.