By Paula Martinac, SF Gate
Fruits and vegetables come in all the colors of the rainbow, making a striking display in a basket or on your plate. The colors are more than pretty, though; they also reflect the presence of powerful phytonutrients, naturally occurring chemicals that shield plants from disease and bacteria while they are growing. When you ingest plant foods in a spectrum of colors, you reap the benefits of these phytonutrients. Although research is inconclusive about the health benefits of any single phytonutrient, “eating the rainbow” is a recognized way to promote overall good health.
Orange and Yellow
Orange- and yellow-colored foods are rich in beta-carotene, a potent antioxidant that may help protect your cells against damage from environmental toxins and the natural aging process. These foods include carrots, cantaloupe, mango, yams, sweet potatoes, squash and apricots. Some laboratory studies suggest that a diet high in beta-carotene may reduce your risk of developing certain cancers, including breast, colon, endometrial, lung and prostate.
Blue and Purple
Foods that are blue and purple in color contain compounds called flavonoids. Blueberries, blackberries, plums, cherries and purple grapes are good sources of a flavonoid known as anthocyanin, which may help increase the vitamin C levels in your cells. This can boost immunity and help prevent damage from free radicals, rogue molecules that can alter DNA. Anthocyanins may also act as anti-inflammatories, and thus protect against heart disease and stroke.
Many red fruits and vegetables contain lycopene, another strong antioxidant. Tomatoes, red cabbage, pink grapefruit, watermelon and guava are significant sources of this phytonutrient. A few promising studies have found that diets high in lycopene may help lower the risk of certain cancers, most notably of the prostate. Levels of lycopene appear to be higher in cooked tomatoes, such as those found in sauce and paste, than in fresh tomatoes.
Green foods such as broccoli, kale, collards, spinach, green beans and cabbage contain an antioxidant phytonutrient called lutein. In conjunction with another compound called zeaxanthin, lutein may help protect eyes against two common diseases of aging, macular degeneration and cataracts, both of which result in blindness. The American Optometric Association states that lutein and zeaxanthin work together as a filter in the eye, shielding the retina from damaging light rays.
- The Cancer Project: The Nutrition Rainbow
- The Real Vitamin and Mineral Book; Shari Lieberman, Ph.D., and Nancy Bruining, MPH
- American Cancer Society: Phytochemicals
- Linus Pauling Institute: The Possible Health Benefits of Anthocyanin Pigments and Polyphenolics
- American Cancer Society: Lycopene
- Cancer Research: Lower Prostate Cancer Risk in Men with Elevated Plasma Lycopene Levels
- American Optometric Association: Lutein and Zeaxanthin
This article was written by Paula Martinac for SF Gate.