Broccoli heads are better for you, antioxidant-wise, if you combine eating them with spicy vegetables such as radishes.
We've known for years that eating broccoli, and specifically broccoli sprouts, is a good way to add the antioxidant sulforaphane to your body. But science is never as simple or straightforward as you think. The human body is a complex organism, and the more researchers look at health promoting factors, the more they realize many work best when combined in the body with other compounds.
Such is the case with sulforaphane. Researchers at the University of Illinois have found that to get the most benefit from eating broccoli, it's best to spice it up with broccoli sprouts, mustard, horseradish, or wasabi. The spicier, the better.
When broccoli sprouts where eaten with broccoli powder (dehydrated broccoli heads), the health promoting compounds were much higher than when these foods were eaten separately. It seems the enzyme myrosinase is necessary for sulforaphane to form. By eating foods containing this enzyme, your body is able to utilize the sulforaphane better. The broccoli sprouts were able to lend the myrosinase to the broccoli powder to help it form more sulforaphane in the body.
Other foods that offer a similar benefit when combined with broccoli include radishes, cabbage, arugula, watercress, and Brussels sprouts. Eating 3 to 5 serving a week of broccoli combined with one of these foods is plenty to get the necessary amount of sulforaphane your body needs. Whether eaten raw or cooked, you'll still get the benefit.
This research just reminds me to eat a variety of different fruits and vegetables and to push the envelope of spicing up your foods.