Food synergy: a relatively new science says the key to health may be not what you eat, but how you eat. Here's how to make it work for you

Better Nutrition, Jan, 2006 by Jennifer Acosta Scott

When you add a steaming heap of broccoli to your dinner plate, you're sure that you are eating healthfully. And it's true. You are. Because foods rich in disease-fighting phytochemicals, like broccoli, are smart additions to any diet.

But suppose you could get even more health benefits from that broccoli by eating it with certain other vegetables. This idea is in line with a relatively new science called food synergy, which says that the key to health may not be what you eat, but rather eating food combinations that biochemically balance each other.

When that happens, it makes already nutritious foods even more so, says David Jacobs, PhD, professor of epidemiology at the University of Minnesota, who focuses on nutritional aspects of epidemiology. For example, a study in the December 2004 issue of the Journal of Nutrition, found that eating broccoli and tomatoes together offers better protection against prostate cancer than eating them separately. Findings such as these emphasize the importance of getting your nutrients from a combination of whole foods.

"The body's interaction with the biochemicals in food is very complex," Jacobs says. "It depends on all the things that are there at once."

The easiest way to take advantage of food synergies is to eat a wide variety of foods, especially fruits, vegetables, legumes, nuts and whole grains. But a few specific combinations can ensure that your body gets the maximum benefits from certain healthful foods.

grapes and apples; a heart-healthy combo

The next time you're whipping up a fruit salad, make sure to include these naturally sweet goodies. Apples contain the flavonoid called quercetin, and grapes contain catechin. Studies show that pairing the two compounds may improve cardiovascular health by making blood platelets less sticky so they don't clump together and clog arteries. "The combination tends to have a mild anticoagulant effect," says Barry Halliwell, PhD, nutrition professor at the National University of Singapore, who co-authored a study on quercetin and catechin.

Don't care for apples and/or grapes? Other quercetin-rich foods include raspberries, buckwheat and onions; catechin is also found in red wines and green and black teas.

the power of a peanut butter sandwich

The grade-school lunch favorite is back--this time as a nutritional powerhouse. Pairing peanut butter with whole wheat bread enables the body to get the proper sequence of amino acids, which are important in making protein. "When your body is synthesizing proteins, it needs all the amino acids there at the same time," says Diane Birt, PhD, a professor of food science at Iowa State University. "Wheat lacks some amino acids. Peanuts have the amino acids lacking in wheat. Together they make a whole."

Over the long term, protein deficiencies can result in a compromised immune system and stunted growth in children. If you're trying to get in shape, insufficient protein intake can also affect your ability to build muscle. Fortunately, protein problems aren't that common in developed countries where a wide variety of foods is available, Birt says. So think of that peanut butter sandwich as a protein boost rather than a dietary staple.

add some fat to your salad

It may sound counterintuitive to healthful eating, but dropping your fat-free dressing in favor of a low-fat version may actually be a smart idea, nutritionally speaking. An Iowa State University study that was reported in the American Journal of Clinical Nutrition found that people who ate salads with full- or low-fat dressings were better able to absorb lutein, a carotenoid (pigment-based plant compound) important in vision health. "With fat-free dressing, they essentially saw no evidence of the carotenoid showing up in the blood," Birt says.

If you're fiercely loyal to your fat-free ranch, Birt suggests adding some fat to your salad in other ways. Moderate amounts of cheese, nuts or avocado can replace the oils needed to get the maximum benefit from your salad veggies.

spice up that burger

Ground beef--and many cuts of poultry and pork--often contains heterocyclic amines (HCAs), cancer-causing compounds that form when meats are cooked at high temperatures. So should you shun your beloved burger? Hardly. A recent study at Kansas State University found that sprinkling rosemary extract on ground beef before cooking it significantly reduces the formation of HCAs was presented at the March 2005 Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy meeting in Orlando, Florida.

1. Scott Smith, PhD, food chemistry professor and lead researcher on the study, says certain types of antioxidants in rosemary extract can block the formation of HCAs. Basil and oregano contain similar antioxidants, though they are not as plentiful, Smith says. Look for rosemary extract at health food stores.

iron: not just for carnivores anymore

If you're a regular consumer of red meats such as beef and lamb, your body's probably getting all the iron it needs. But what if you prefer bean sprouts to steaks? The key is to combine foods rich in vitamin C with plant-based iron sources, says Pat Vasconcellos, registered dietitian and spokesperson for the American Dietetic Association.