Eat this with that: How food works in tandem to boost nutrition

Eating certain foods in tandem helps the body absorb nutrients more readily

The next time you're preparing a spinach salad, toss in a mandarin orange. The citrus fruit won't just enhance the flavor; its vitamin C will help your body absorb the iron found in leafy green vegetables.

But these nutrients aren't necessarily the only team players on your plate. A growing number of foods have been shown to have a "one-plus-one-equals-three" effect when eaten together, said dietitian Wendy Bazilian who holds a doctorate in public health.

"They give you a stronger defense than if consumed separately," said Bazilian, author of "The Superfoods Rx Diet" (Rodale, $25.95).

Tomatoes and broccoli, for example, have more powerful cancer-fighting qualities when eaten at the same time than when consumed alone, according to University of Illinois researchers. Adding vinegar to sushi rice has been shown to decrease the glycemic index of the rice by as much as 35 percent. And combining foods that contain carotenoids, such as tomatoes, with a healthful fat, such as olive oil, makes it easier for the body to absorb the nutrients more readily.

"It's not that one nutrient doesn't work; it's that two or three work better," said dietitian Elaine Magee, author of "Food Synergy" (Rodale, $19.95).

When foods are "bioavailable," they're ready for the body to absorb and use. But we often unwittingly make decisions that interfere with the body's ability to maximize these "good" nutrients.

The use of fat-free salad dressing instead of one containing a healthful fat is a common mistake.

"Locked up inside that salad is nearly every antioxidant you've ever heard of," Dr. John La Puma wrote in "Chef MD's Big Book of Culinary Medicine (Crown, $24.95).

If you use fat-free dressing, he wrote, "you're getting less than you could—unless you eat that salad with avocado, or with walnuts or roasted walnut oil, or extra-virgin olive oil or nearly any other good-for-you fat."

The reason, La Puma said, is that the oil makes several nutrients—the lutein in the green peppers, the capsanthin in the red peppers, the lycopene in the tomatoes, even the limonene in the lemon—more body ready for you. "Each of them is optimally absorbed with a little bit of fat," he wrote.

The best way to spot synergy on your plate—and to ensure a nutritious meal—is to make sure it has a minimum of three colors and contains healthful fat (avocado, olive oil or nuts), Bazilian said.

"Food has a way of working synergistically, whether or not it's an outright pairing, so you're not constantly drinking tea and eating spinach. Certain nutrients help each other out."