In a greenhouse in Beltsville, Md., Steve Britz aims light-emitting diodes at rows of plants, hoping to coax more color out of the leaves.
Across the country, in a lab in Pomona, Calif., David Still painstakingly manipulates plants’ genetic structure, altering the DNA of some, crossbreeding others, then microscopically analyzing their progeny.
Though their approaches and technologies are as far apart as their workplaces, the two have a common goal: to build a better head of lettuce.
Specifically, Britz, a research plant physiologist with the USDA’s Agricultural Research Service, and Still, a professor of horticulture and plant and soil science at California State Polytechnic University at Pomona, seek to create varieties of lettuce that contain more antioxidants.
Antioxidants are darlings of the nutrition world, valued for their purported health-promoting and disease-busting qualities.
But even as Britz and Still toil away, neither is sure antioxidants are all they’re cracked up to be.
To get an idea of where the research stands, let’s drop the “anti” and start with “oxidants.”
The body’s daily functions, such as breathing and metabolizing food, and its exposure to such environmental hazards as pollution, produce stray molecules known as free radicals, which can oxidize, or interact with oxygen molecules, and damage cells.
Antioxidants can engage the free radicals before they do harm. Each antioxidant, from the anthocyanins and caretenoids to isoflavones and lutein, is thought to protect against a certain kind of cell damage. Vitamin C and lycopene, for example, are thought to reduce DNA damage.
These chemicals, often evidenced by the bright colors they impart, also help protect plants against environmental stresses.
One of the great mysteries about antioxidants is whether they can work in isolation, as when they are taken in dietary supplements, or whether their efficacy depends on their interactions with one another and perhaps with other substances.
Another is whether they can do harm: Recent research showing that vitamins C and E, taken as supplements, may reduce the benefits of exercise has cast a pall on antioxidant supplements.
Victoria Drake, a research associate at the Linus Pauling Institute at Oregon State University, put it this way in an e-mail: “Looking at the epidemiological data we have to date, we know … that diets rich in fruits and vegetables (antioxidant-rich foods) can reduce the risk of chronic diseases, such as cardiovascular diseases. But evidence that very high doses of individual micronutrients or phytochemicals can do the same is inconsistent and relatively weak.”
Yet Britz and Still continue their work with lettuce.
Both believe it might lead to development of plants whose high levels of antioxidants might help them grow better and withstand the degradations of shipping.