Have you ever heard the phrase “eat a rainbow a day?” It refers to consuming fruits and vegetables in a variety of colors. More than 2,000 different pigments contribute to the beautiful colors of our produce and they all represent unique health benefits. If we eat a variety of colors, we also get a variety of nutrients.
These pigments are so important because we can only get these compounds from plants – mostly fruits and vegetables, and some from whole grains, beans and nuts. They are called phytochemicals. The prefix “phyto” means “plant” in Greek. See if you recognize any of them:
Red – Lycopene
Think tomatoes, watermelon and pink grapefruit. Strawberries and cherries, though red, get their color from another compound called anthocyanins – more on those later! Lycopene is what we consider an antioxidant. Any antioxidant prevents dangerously charged particles from bumping into our DNA, causing unwanted changes or abnormal cell growth – triggers of cancer. Lycopene has shown a specific benefit for reducing risk of prostate cancer, as well as improving outcomes for those already diagnosed with prostate cancer.
Orange – Alpha and Beta Carotene
Fall is just around the corner, and with that comes an abundance of orange produce. Sweet potatoes, pumpkin, carrots, and acorn or butternut squash are all great options, as well as cantaloupe, mango and apricots. Both alpha and beta carotene are from the carotenoid family, which requires a tiny bit of fat to be absorbed. A little bit of salad dressing, an avocado on a sandwich, or trail mix with nuts is more than enough to do the trick. Alpha and beta carotene are often converted to vitamin A once inside the body – a vitamin crucial for good immune system health. They are also antioxidants.
Yellow – Lutein and Zeaxanthin
Keep your eyes on the prize with these yellow guys. Also from the carotenoid family, both compounds are best known for eye health. They reduce risks of both macular degeneration and cataracts, two of the leading causes of blindness in the United States. Both lutein and zeaxanthin build up in our retinas, acting as antioxidants. These compounds are easy to spot in corn and yellow bell peppers, but most of the time the yellow pigment is masked by darker green colors. Kiwi, green bell peppers, honeydew, and dark leafy greens like spinach, kale, romaine lettuce and collard greens all have them too.
Green – Chlorophyll
You may remember this name from back in middle school biology class. Chlorophyll: the lifeblood of plants and the conductor of photosynthesis. Chlorophyll is what makes leaves and grass green. Turns out, the chlorophyll we eat from dark leafy greens as well as parsley, green beans, sugar snap peas or leeks binds to cancer-causing compounds preventing them from being absorbed by our intestines. Look to these greens for improved wound healing too, as they have antibacterial properties.
Blue and Purple – Anthocyanins
This is a vast group including some reddish produce also: blueberries, eggplant, strawberries, cherries, grapes, beets, and purple cabbage. Part of the reason anthocyanins are so dark is because they are the plant’s way of protecting itself from the UV radiation of the sun. Anthocyanins are considered one of the most powerful antioxidants, and much of the reason berries are considered to be a “superfood.” After all, most berries are red, blue or purple. Another large benefit of these compounds is related to heart disease prevention. Anthocyanins help keep blood vessels relaxed instead of rigid, as well as preventing LDL cholesterol from building up. As if that wasn’t enough, here are a few more bonuses: increased blood flow to all parts of the body, reduced blood pressure, and reduction of inflammatory proteins.
White – Glucosinolates
Though not technically part of the rainbow, don’t forget about white vegetables. Natural detoxifiers called glucosinolates contain sulfur, which is why they may be described as having a bitter taste, or a “bite.” Onions, parsnips, cauliflower, garlic, turnips and rutabaga would be examples, but mushrooms and potatoes are white too. These compounds are actually the plant’s way to avoid being eaten by insects and animals like deer or rabbits – they don’t care for the bitter flavor either! Cooking these white veggies will not only change the flavor, but enhance some of the benefits including their antibacterial properties and cancer-fighting power. Glucosinolates are involved in everything from promoting cancer cell death, to managing estrogen production, preventing the spread of cancer cells, and increasing immune cell response.
Just remember that these compounds were meant to be consumed in nature’s packaging – as whole fruits and vegetables. Many supplement options are available for these compounds individually, but rarely show actual benefit or reduction in disease over the long-term. Save your money and savor the flavors instead!