We’ll end this week with a brief mention of some of the
current thinking about diet and health. You may have seen articles in newspapers and
magazines touting the health benefits of "anti-oxidants" and
"phytochemicals." Most of us have been admonished at one time or another to
"eat our vegetables." As interest in nutrition—and the aesthetics of
food—grows, we’re seeing more bright red peppers and purple cabbage in our
salads, and slivers of orange cantaloupe and citrus as garnishes, and other brightly
colored vegetables gracing our plates. Now scientists are discovering that these bright
colors please more than the eye. Brightly colored foods also contain important substances
called antioxidants. Antioxidants are believed to stop the action of free radicals,
substances implicated in a host of maladies including cancer and premature aging. Perhaps most interesting of all, the bright color doesn’t just
indicate the presence of antioxidants—the color is the
antioxidant! The actual pigments—the chemicals that give things their
color—provide the disease-fighting benefits.
There are several groups of phytochemicals, present in
different amounts in different foods. The carotenoids are a group of red, orange, and
yellow pigments. They are abundant in richly colored foods like carrots, sweet potatoes,
red peppers, pumpkin, and tomatoes. They are also present in many green
vegetables—especially leafy green vegetables like kale and spinach. (Remember that
chlorophyll is a strongly colored pigment, and can mask the other pigments.) A blue or
purple color usually indicates the presence of anthocyanins, another type of antioxidant.
Blueberries, raspberries, red cabbage, plums, and even red wine are rich in anthocyanins.
Just as chlorophyll is the green pigment that absorbs
light so that photosynthesis can take place, other pigments of other colors also intercept
light. Scientists believe that these other pigments absorb light in a way that protects
the plant. For example, the anthocyanins filter out harmful ultraviolet light, protecting
the plant against damage. When we eat plants rich in carotenoids, these pigments may also
act to protect us from the sun’s harmful rays. Scientists speculate
that antioxidants also enhance the immune system. It’s a convincing argument to add
more brightly colored fruits and vegetables to our diets!
That’s it for this week. See you next week!
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