From Seed to Seed:
Plant Science for K-8 Educators

And now a word about diet and health... You may have seen articles in newspapers and magazines touting the health benefits of "antioxidants" 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 pepper and purple cabbage in our salads, 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 compounds called antioxidants. Antioxidants are believed to inhibit the action of free radicals, compounds implicated in a host of maladies including cancer and premature aging.

Perhaps most interesting of all, the bright color does not simply indicate the presence of antioxidants-the color is the antioxidant! The actual pigments-the chemicals that absorb light and 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 carrot, sweet potato, red pepper, pumpkin, and tomato. 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 for you and your students to add more brightly colored fruits and vegetables to your garden and diets!

And research shows that there is a direct link between nutrition and learning. Students will be ready to learn and achieve their fullest potential only if they are well-nourished and healthy. The California Department of Education reports that hungry children score lower on achievement tests, are more susceptible to illness, miss school more often, have diminished attention spans, require more disciplinary intervention by their teachers, and are at higher risk for dropping out of school.

Would you like to know more?
Additional Online Resources

• Eat 5 A Day for Better Health-The 5 A Day program is the nation's largest public/private partnership and the only initiative promoting all produce.
  http://www.5aday.com
  

• United States Department of Agriculture: Science 4 Kids-Agricultural ideas for science fair projects, including experiments on seeds, fruit ripening, nutrition and microorganisms.
  www.ars.usda.gov/is/kids/fair/ideasframe.htm

Relevant Books
K-4
Ehlert, Lois. 1987. Growing Vegetable Soup. Harcourt Brace. ISBN: 0-1523-2575.

Pallotta, Jerry. 1994. The Spice Alphabet Book. Charlesbridge Publishing. ISBN: 0-8810-6897-7.

Rockwell, Lizzy. 1999. Good Enough to Eat: A Kid's Guide to Food and Nutrition. Harpercollins Juvenile Books. ISBN: 0-0602-7434-4.

5-8
Bourgeois, Paulette. 1991. The Amazing Potato Book. Addison-Wesley Publishing Company. ISBN: 9-9926-4016-2.

Cochrane, Jennifer. 1990. Food Plants. Steck-Vaughn. ISBN: 0-8114-2733-1.