Radical solutions: protect your health with antioxidants

You could be walking down the street when it hits you. An invisible molecule of, say, air pollution enters your body. It ricochets around inside you, chewing up genes. Years later, seemingly out of nowhere, you're diagnosed with cancer.

Called free radicals, these invaders are a big reason you age and develop degenerative diseases such as cancer and heart disease.

Normally, electrons--negatively charged particles--come in pairs. But when an atom is short one electron, or has one too many, it's called a free radical.

It's "free" in the sense that, being unpaired, it's aggressively seeking a mate--and it is likely to steal an electron from one of your normal cells. Losing an electron damages either the exterior membrane or the contents of the cell. Called oxidation, this is the same process that turns iron rusty, butter rancid and bananas brown.

A host of magazine articles have given any oxidation a bad name. But in limited quantities, oxidation can be beneficial: It generates energy and kills bacterial invaders.

An excess of free radicals, however, creates problems. If a free radical picks up an electron from one of your DNA atoms, then part of your DNA has been damaged.

But DNA reproduces itself, right? Yes, but when damaged DNA replicates, it doesn't make normal DNA. Instead, it mutates; it creates more damaged DNA--which makes more damaged DNA, and so on. It's the process we know as cancer and aging.

A leading theory suggests that aging and cancer start not with a million invaders or even a million internal cellular recruits, but with one renegade cell gone amok, which starts its own growth program within one of the body's tissues. The billions of cells in a cancerous tumor are cast in the image of their single, renegade ancestor: that one free radical-damaged cell.

Free radicals may also cause more than 60 degenerative illnesses that accompany aging. These include memory loss, heart disease, stroke, Parkinson's disease, cataracts and emphysema.

Ideally, we should avoid excess sources of free radicals. Air pollution, pesticides, radiation and sunlight are the main sources of free radicals. Also, inflammation and infections trigger the immune system to use free radicals to kill bacteria; the number of free radicals often increases as a by-product. What's more, a diet lacking in antioxidant-rich foods cannot effectively suppress free radicals.

Antioxidants neutralize free radicals by donating one or more of their electrons to make up for the missing electron in the radical. That keeps free radicals from stealing from your vital cells.

Several studies have proven that people who eat adequate amounts of antioxidant-rich fruits and vegetables have lower incidences of cardiovascular disease, certain cancers and cataracts. But while fruits and vegetables are rich in antioxidants, it is not known which dietary factors are responsible for the beneficial effects. After all, every plant food contains hundreds of phytochemicals--plant chemicals--and that includes over a dozen families of antioxidants with strange names: anthocyanins, tocotrienols, carotenoids, flavonoids, catechins and even some vitamins such as A, C and E.

No Answer Yet

There's no doubt that foods provide needed antioxidants. But what about dietary supplements?

In 1993, The New England Journal of Medicine published two studies that found that people who took vitamin E supplements had fewer deaths from heart disease. But do such studies constitute proof of disease prevention? Not necessarily. These studies didn't rule out the other lifestyle factors or consider death rates from other diseases.

The most recent epidemiological study of vitamin E and carotene supplements--published in the June 14, 2003 issue of The Lancet--covered 15 studies and 200,000 subjects. It found no cardiac benefit in those already somewhat afflicted by heart problems. In response to the findings, John Hathcock, PhD, vice president of the Council for Responsible Nutrition, argues that the study still cannot dismiss a possible "primary benefit"--that is, prevention for the non-afflicted.

So, do these studies disprove the idea that antioxidants work once they are removed from food? No. Science cannot disprove anything; studies either prove a hypothesis--or fail to prove it.

In fact, there is only one way to settle the question scientifically: long-term, double-blind clinical studies comparing antioxidant users to nonusers and checking death rates from all causes. So far, no such study has been conducted. We may discover that, in order to be effective, antioxidants need other compounds that are found in foods--compounds not furnished in extracted supplements. And although many supplements are marketed as "concentrates" of fruits or vegetables, a 1995 assessment in Consumer Reports on Health noted that it's impossible to condense large amounts of produce into a pill without losing huge quantities of antioxidants--not to mention fiber and nutrients. Increased intake of produce is your surest bet. In fact, antioxidant supplements cannot legally be advertised to prevent disease. Also, supplements of the antioxidant beta-carotene might carry some risks, especially for smokers. Past research suggests that smoking oxidizes excess beta-carotene in the lungs, creating substances that decrease a tumor suppressor and increase a tumor promoter. In all fairness, however, dietary supplements are just that--supplements to a nutritious diet, not replacements. So if you're eating only a modest amount of fruits and vegetables, supplements might be of benefit. There's just no proof yet.