Put "age-defying" on any product, and most of us are ripe for the hype. We've gotten lots of help cosmetically, with lip-plumpers, teeth-whiteners, and wrinkle-fillers. Yet, what about a longer, healthier life? According to MORE's online poll, that's what we really want.

While casual Net surfers can find any number of self-proclaimed anti-aging pills and potions, no currently marketed substance -- not one -- has yet been proved to slow or reverse human aging. But in the midst of all this snake oil salesmanship, scientists have been making real progress. Many top academics have formed for-profit companies whose very names -- Elixir Pharmaceuticals, LifeGen Technologies, Longenity -- advertise the fountain-of-youth bent of their research. News of various therapies, including the enticing "anti-aging pill," surfaced last year in the business pages of The New York Times, Fortune, and the Wall Street Journal. Indeed, if a truly effective anti-aging drug were found, the payoff would make Viagra sales look anemic.

So, how close is science to delivering your top three anti-aging priorities, which, according to our poll, are freedom from disease, energetic physical function, and a lively brain? Well, if the most promising research pans out, we could get all three.

Once, even doctors thought that a bent-over spine, painful joints, sadness, and mental confusion were simply part of getting old. Now we recognize these as symptoms of disease (osteoporosis, arthritis, depression, and dementia), and we seek to prevent and treat them.

Biologically, aging is still not completely understood. Most scientists define it as the accumulation of random damage to the building blocks of life -- especially to DNA, and to certain proteins, carbohydrates, and fats. Some of this random damage comes from free radicals -- those necessary, but highly reactive, molecules released during metabolism, which sustain life by converting what we eat into energy. The body's self-repair mechanisms fix most of the damage, but not all. As we grow older, the repair mechanisms don't work as well, allowing free-radical damage to accumulate; cells, tissues, and organs become impaired, and we become more vulnerable to disease. That results in characteristic signs of aging: loss of muscle and bone mass, decline in reaction time, reduced hearing and vision, thinner and less elastic skin.

People with the right mix of genes, such as centenarians who come from family clusters of long-lived people, seem better able to withstand routine wear and tear in the cells. For instance, smoking damages DNA, putting smokers at much higher risk for many diseases -- but tell that to Helen Faith Reichert, a 102-year-old who has smoked all her adult life. If anti-aging scientists succeed in "bottling" some part of Reichert's genetic defense, more of us might join the centenarian club.