The Colors of the Food Rainbow
The next time you sit down for a meal take a good, long look down at your plate or bowl. Anything green or orange down there? What about yellow or purple or red? (ketchup doesn’t count)
If the answer is “yes” (and assuming you’re not eating Skittles or peanut M&Ms for dinner) then good for you; you’re likely getting plenty of high-fiber, low fat, nutrient dense vegetables and fruits in your diet.
But have you ever wondered what gives those fruits and vegetables their distinctive colors? And have you ever stopped to consider that the compounds which lend those plants their color – what makes oranges orange or blueberries blue – can actually help prevent disease in its early stages and even halt or reverse disease in late stages?
Soon after my prostate cancer diagnosis I adopted a whole-food, plant-based (WFPB) diet after consultation with my naturopathic urologist, Dr. Geo Espinosa. Study after study has shown that a high intake of animal protein, particularly dairy products, is correlated with an increased risk of prostate cancer. A Harvard review of research conducted in 2001 showed that men with the highest dairy intakes had approximately double the risk of prostate cancer and up to a 400% increase in the risk of metastatic or fatal prostate cancer.
A WFPB diet, by contrast, is full of disease-fighting vitamins, antioxidants and anti-inflammatory phytochemicals, many of which give fruits and vegetables their color. It’s also a low-calorie density and nutrient-rich diet, which means that you can eat more of these healthful foods and feel satisfied without stuffing yourself with calories that, if not used, will be stored as fat.
I like to use this chart, from Forks Over Knives, to illustrate this concept:
A WFPB diet is a veritable food rainbow. Each color has its own chemical signature and disease-fighting properties.
Foods like broccoli, brussels sprouts and kale get their green color from compounds called glucosinolates, which are transformed in the body into anti-carcinogenic isiothiocyanates and indoles. The chemicals found in cruciferous vegetables (including cauliflower in addition to those listed above) have been shown to impact cancer initiation and angiogenesis (the process by which tumors create their own blood supply in order to proliferate)
Orange foods like mangoes, carrots, sweet potatoes, apricots, squash, peaches and pumpkins are full of carotinoids, which are transformed into Vitamin A, a powerful anti-oxidant which plays a role in cell differentiation, in modulation of the immune system, in regulation of cell proliferation and in the synthesis of hormones.
Orange-yellow foods like oranges, grapefruit, lemons, tangerines, papaya, pineapple and green grapes are chock-full of flavanoids, which have anti-viral, anti-inflammatory and antioxidant properties.
Lycopene, which is found in red foods like tomatoes, tomato soup, tomato sauce and tomato juice is a powerful antioxidant which plays an important role in intercellular and intracellular communication; it has also been shown to reduce the risk of prostate cancer by almost 30%. Other red foods, like raspberries, strawberries, cranberries, red cabbage, cherries, beets, red apples and red onions, contain anthocyanins, another powerful antioxidant.
Purple and blue foods like blueberries, red grapes and blackberries also contain anthocyanins in addition to phenols, which are powerful antioxidants and which are very effective at absorbing the sun’s ultraviolet radiation.
Green-yellow foods like spinach, Romaine lettuce, peas, honeydew melon, kiwi and leafy green vegetables contain zeaxanthin and lutein, which can arrest the cell cycle, thereby preventing cell division and stimulating damaged cells, including cancer cells, to apoptosis (the spontaneous death which is programmed into every normal cell but which gets overridden in cancer cells, enabling uninhibited tumor growth).
White or cream foods like garlic and onions contain allicin, a powerful antioxidant that is also antiviral, anticarcinogenic and detoxifying. Allicin plays an extremely important role in reducing the risk of stomach cancer (by as much as 40%).
Unless you’re a dietitian or nutritionist there’s no need to memorize all the phytochemicals and what they’re good for (keep the infographic below, from Food Revolution Network, handy). You just need to remember to eat a broad variety of fruits and vegetables from across the food rainbow to make sure you’re getting all the antioxidant, anti-inflammatory, anti-aging vitamins, minerals and nutrients possible as part of a healthy, balanced diet.
And it’s not hard to incorporate the colors of the food rainbow into your daily Nutrition practice. Make a big salad for lunch or even dinner (make sure to add healthy fats from avocados or seeds or nuts and lean protein to power your lifestyle). Stir fry or roast a mess of colorful vegetables and serve them over a grain of your choice. And don’t let your childhood prejudices hold you back; if you still don’t like broccoli or Brussel sprouts or cauliflower you just haven’t found the right way to prepare them yet. Keep trying; you won’t be sorry.
Because there’s gold (and every other color) at the end of the food rainbow: a robust immune system; healthy skin, teeth and bones; lean muscle mass and appropriate levels of body fat; a healthy gut; and a keen, active mind.