DEAR DR. BLONZ: I remain confused about oxidation. It is said to be part of metabolism, but we also hear the repeated advice to get "antioxidants" from our foods or supplements in order to keep oxidation from taking place. I am hoping you can clear this up. -- A.Q., San Jose, California
DEAR A.Q.: It does seem like a paradox at first glance: Oxygen is essential for life, so why would we want any substances to work against it?
The answer rests with oxygen's tendency to react and combine with other elements in various circumstances. It is good when oxygen combines with fat, carbohydrate or protein in a programmed, disciplined way, producing energy and building body tissues and substances. As part of our defenses, oxygen reacts with and disables dangerous organisms or substances -- another way oxidation proves its essential mettle.
But what about oxygen's ability to react with stuff in the wrong way, or at the wrong place and time? This is an omnipresent threat to plants, which need to sprout, grow and reproduce amid the oxidizing rays of the sun. Each plant relies on its unique complement of phytochemical antioxidants to keep things under control.
In the human body, errant oxidation can be a risky business, playing a role in heart disease, cancer, aging, bacterial and viral ailments, and general forms of inflammation, including arthritis. We cannot produce the variety of antioxidants found in plants, which explains why certain nutrients are designated as "essential." A plant-based, whole-food diet continues to prove the most healthful type.
The understanding of oxidation, and the discovery of antioxidant compounds, is an example of science giving us chapter and verse of what makes certain foods so good for us -- and conversely, what happens when we fail to give the body what it needs to maintain our health.
Symphony music provides an apt analogy. Think of the ultimate conductor, with a talent honed over generations of family traditions and training. Conductors direct musicians to play their parts and follow instructions with every nuanced flick of the baton. The result? Quality music, analogous to good health in our story. If those instruments are out of tune, or if the musicians don't follow the score, the result is disharmony that even the best conductor might not be able to fix. Or, it may be the conductor that's the problem.
The body has defenses to allow healthful oxidation while preventing the errant version from causing harm. These defenses rely on a supply of antioxidant nutrients, including vitamin C, carotenoids, vitamin E and selenium. These are found in vegetables, fruits and grains, where they serve this protective purpose for the plant in the soil; on the plate, they can work as allies for our body's defenses.
A well-nourished body is maintained on various nutrients, ideally from a variety of whole plant foods, where substances evolved to work together. Contrast this with dietary supplements, where certain antioxidants are singled out and promoted. In that music analogy (also applicable to any team effort), this might occur when attention and funding get devoted to the stars, while the essential supporting cast is neglected. Avoid relying on one substance or supplement; such an approach will neglect important supporting players.
Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.