Food Synergy

Vitamin C enhances the body's absorption of iron. So protein eaten together with a salad laced with lemon juice has a dynamic effect.

There is still much we don't know about how the components in food work together. Over the past 20 years, scientists have identified hundreds of plant-food components called phytochemicals (also called phytonutrients). A decade ago, we didn't even know about phytochemicals like lycopene (tomatoes, watermelon) or anthocyanins and pterostilbene, which placed blueberries in the superfood category.

We know that eating food as close to its natural form as possible is our best bet for improving health and preventing disease. Vegetables, fruit, whole grains, nuts, and legumes are great examples of foods that are rich in a combination of important vitamins, minerals, fiber, protein, antioxidants.

Here are examples in which different nutrients and components in food work together:

* Pairing broccoli with tomatoes. Published in December 2004 in the Journal of Nutrition, prostate tumors grew much less in rats that were fed tomatoes and broccoli than in rats who ate diets containing broccoli alone or tomatoes alone.

* Antioxidants vitamin C and vitamin E; isoflavones from soybeans and other compounds are thought to be important in slowing the oxidation of cholesterol - important to reducing your risk of heart disease and lowering your blood cholesterol. Antioxidant protection is a complex system that includes many nutrients and phytonutrients. You need all of them for maximum effect.

* Three B vitamins (folic acid, vitamin B-6, and B-12) TOGETHER reduce the level of an amino acid that, in high levels, is thought to damage artery linings.

* Studies have shown that vitamin C and the phytoestrogen found in various fruits and vegetables, whole grains, and beans work together to inhibit the oxidation of LDL "bad" cholesterol.

* The phytochemicals quercetin (found mainly in apples, onions and berries) and catechin (found mainly in apples, green tea, purple grapes, and grape juice) work together to help stop platelet clumping. Platelets are a component in blood that play an important role in forming clots. Platelets' clumping together is one of several steps in blood clotting that can lead to a heart attack.

* The Mediterranean-style diet, rich in plant foods, whole grains, legumes and fish; low in meat and dairy products; and containing more monounsaturated than saturated fats because of its emphasis on olives, olive oil, and walnuts is an excellent example of food synergy. A recent study concluded that the Mediterranean diet may reduce the prevalence of metabolic syndrome - excess body fat, high blood fats, and high blood pressure and the cardiovascular risk that goes along with it. Another study found that a Mediterranean diet was associated with a 23% lower risk of early death from all causes.

* Several factors - including saturated fat and dietary cholesterol - work to raise cholesterol in the human body. Several others, like plant sterols, soy protein, soluble fiber, and foods such as oats and nuts, help lower blood cholesterol levels. Your cholesterol levels are determined less by the intake any particular nutrient than by your overall diet.

* Eating a little "good fat" along with your vegetables helps your body absorb their protective phytochemicals, like lycopene from tomatoes and lutein from dark-green vegetables. A recent study measured how well phytochemicals were absorbed after people ate a lettuce, carrot, and spinach salad with or without 2 1/2 tablespoons of avocado. The avocado-eating group absorbed 8.3 times more alpha-carotene and 13.6 times more beta-carotene (both of which help protect against cancer and heart disease), and 4.3 times more lutein (which helps with eye health) than those who did not eat avocados.

* Cornell University researchers found that apple extract given together with apple skin worked better to prevent the oxidation of free-radicals (unstable molecules that damage cells and are believed to contribute to many diseases) than apple extract without the skin. They also found that catechins (a type of phytochemical found in apples), when combined with two other phytochemicals, had an effect that was five times greater.

* Oats may help protect against heart disease. Besides being one of our best sources of soluble fiber, oats contain an extensive list of other healthful compounds, including beta-glucan; a beneficial amino acid ratio, magnesium, folic acid, tocotrienols, and a phytochemical so far identified only in oats - avenanthramides. The protective effect of oats is thought to come from the collective effects of all of these components.