Page 2 of 2   <      

Amid Efforts to Give Foods More Antioxidant Punch, Mysteries Remain

Trey Ideker, who holds posts in the schools of medicine and engineering at the University of California at San Diego, has found in laboratory tests that some limited exposure to oxidants may equip cells to better withstand larger exposures. His work, if borne out in humans, could have all kinds of implications for our understanding of aging and disease.

Most of the evidence on which antioxidants' reputation is based comes from studies of isolated cells exposed to plant chemicals or from research on rats and mice. While much of the research is compelling, none of it shows how antioxidants actually affect human health.

And those human studies may never take place, Still said in a telephone interview. "The only way to prove [antioxidants' benefits] would be to provide [subjects] a diet devoid of antioxidants, which would be very difficult, as antioxidants are fairly abundant in the food supply, or to produce a mutation in mice that [left them without] the capacity to arrest free radicals."

In any case, Britz and Still both observe that while we have a hunch that antioxidants are good for us, in fact they're not clearly essential to our health.

"They're not like vitamins," Britz notes. "They're not necessary in that you don't get a deficiency response if you don't have them." (That message is slightly blurred by the fact that some antioxidants, such as Vitamin C, are indeed vitamins that play other key roles in our bodies.)

Yet Britz and Still continue their work with lettuce. Both believe that it might lead to development of plants whose high levels of antioxidants may help them grow better and withstand the degradations of shipping and storage. And, Britz says, altering green lettuce's colors by bumping up the antioxidants might make for a prettier plant.

"If the lettuce is more attractive," he mused, "people might eat more of it -- and less of things that are bad for them."

Check out today's Checkup blog post, in which Jennifer looks at lettuce and other leafy greens. Subscribe to the Lean & Fit newsletter by going to and searching for "newsletters." And e-mail your thoughts to Jennifer at

<       2

© 2009 The Washington Post Company