You are what you eat, the saying goes. This piece of wisdom underscores the body's process of extracting nutrients from food; we get what we put in our bodies, whether it's good or bad.
Some foods may actually combat the aging process because of the nutrients they contain. Under the free radical theory of aging, our bodies wear down as the result of cellular destruction by free radicals. These are molecules or atoms with an unattached electron, produced by normal body processes where oxygen is used, which seek to attach itself to another atom. These radicals can attach to a number of different molecules and atoms; if they attach to a cell's mitochondrial DNA (mtDNA), damage can occur and the cell may eventually die.
Here's where food comes in. Foods containing antioxidants have been shown to neutralize free radicals by stabilizing them. The theory goes that the more antioxidants (like vitamins C and E and beta carotene) are consumed through food, the less chance free radicals have to damage cellular structures, including skin cells.
Studies of the effectiveness of adding antioxidants to stabilize free radicals have come to different conclusions; definitively speaking, the jury's still out. Still, physicians recommend eating a diet rich in antioxidants, such as colorful vegetables and cold-water fish like trout and salmon.