What is better than counting calories? Counting colors.
That’s right, paying more attention to the variety of colors within a diet is wise in terms of overall health, metabolism, and weight loss. Hence why the phrase “eat the rainbow” might be trending now more than ever.
But this is one trend dietitians will wholeheartedly support long term. Dietitians already promote eating plenty of colorful vegetables and fruits daily, but encouraging people to eat rainbow foods sounds a lot more fun!
What Is Rainbow Food?
While many proclaimed superfoods like blue spirulina and green chlorella fall under the umbrella of rainbow food, most rainbow foods including rainbow fruit and vegetables are typical foods. In reality, the term rainbow simply refers to vibrant colored foods. Thus, apples, oranges, spinach, and eggplant are all “rainbow foods!”
But why is this such a trendy subject?
Eating the rainbow is perhaps trendier than ever right now because colorful veggies, fruits, and other foods help boost the immune system. However, their superpowers hardly end there.
Rainbow foods also provide and/or function to:
- Antioxidants
- Phytonutrients
- Fiber
- Bolster cellular health
- Optimize metabolism
- Lead to healthy skin, hair, and nails
- Reduce the risk of every chronic disease
- Promote a healthy weight
- Improve gut health
- Ensure nutrient status
Most importantly, eating a variety of different colored foods is beneficial because different colors provide different nutrients. Consuming fruits and vegetables (at all) is healthful, but a larger variety enhances all of those functions listed above and helps one avoid nutrient deficiencies.
Plus, categorizing foods by color is an easy way to remember their purpose and function. Rather than trying to remember the nutrition of every single food (nearly impossible even for a dietitian!), all one needs to remember is seven to ten different color categories of food functionality.
Eat the rainbow to strike gold in terms of health!
Colored Foods and Their Nutrients
Much of society eats foods primarily based on their taste, cost, and convenience rather than their functionality. Unfortunately, this means a large percent of the population eats a bland, beige diet including mostly crackers, chips, cookies, refined pastas and breads, and other snack foods that are artificially colored. The orange color of goldfish is artificial and hardly exerts the same effects as a ripe navel orange.
Food manufacturers have created many inexpensive beige foods that are high in added sugar, fat, and sodium. These may taste good momentarily, but they will likely cause health detriment down the road. These colorless foods are void of nutrients like vitamins, minerals, fiber, and phytochemicals that support metabolism and cellular health which then translates into overall health.
Conversely, the plant pigments that cause the vibrant color of plant foods signify freshness, safety and again, nutritional value. Each major pigment category includes a family of specific compounds with a unique name and chemical structure within the food.
There are a few major categories of plant pigments:
- Carotenoids: yellow, orange, and red foods
- Anthocyanins: red, blue, and purple foods
- Chlorophylls: green and yellow foods
- Betalains: red foods
- Anthoxanthins: White and brown plant foods
Let’s take a deep dive into each color and which foods provide the most potent form of each pigment.
Red Foods
Lycopene is a powerful carotenoid, as well as an antioxidant, in bright red fruits and vegetables. As a whole, carotenoids are fat-soluble substances best absorbed with fat and strengthened by the cooking process. Some of the most common carotenoids are alpha-carotene, beta carotene, lutein, zeaxanthin, and lycopene.
In addition, some carotenoids can be converted into vitamin A, with the most popular form being beta-carotene, a provitamin A essential for growth, immune function, and eye health.
Lycopene has also been extensively studied for its associations to reduced risk of some cancers, especially prostate. It has also been linked to protecting against heart attacks and disease.
In terms of nutrients, red fruits and vegetables tend to be high in vitamin C, folate, and flavonoids, another compound that reduces inflammation and exerts antioxidant effects.
Red-colored foods also constitute anthocyanins which help prevent bacteria from attaching to cells. Examples of potent red foods are:
- Red apples
- Beets
- Red (purple looking) cabbage
- Cherries
- Cranberries
- Grapefruit
- Grapes
- Red bell pepper
- Pink oyster mushrooms
- Pomegranates
- Red potatoes
- Radishes
- Raspberries
- Strawberries
- Tomatoes
- Watermelon
Orange Foods
Like red foods, orange plant foods also derive their rich color due to carotenoids; the most common ones being beta-cryptoxanthin, beta-carotene, and alpha-carotene. All of these can be converted into vitamin A by the body.
Orange foods are excellent sources of vitamin C, omega-3 fatty acids, and the B vitamin folate in addition to being exceptionally high in vitamin A. As mentioned, vitamin A, literally referred to as the vision vitamin is obviously paramount for vision and nighttime vision. It also plays an active role in immune function, skin and bone health, and antioxidant contribution.
Potent orange foods include:
- Apricots
- Butternut squash
- Cantaloupe
- Carrots
- Mangos
- Nectarines
- Oranges, clementines, cuties
- Peaches
- Pumpkin
- Sweet potatoes
Yellow Foods
Moving down the list but on a similar note, yellow foods also achieve their color thanks to carotenoids. A unique yellow carotenoid is a xanthophyll, housing lutein, and zeaxanthin. It contains oxygen and protects humans from too much sunlight.
Healthful yellow foods are:
- Yellow apples
- Yellow bell pepper
- Yellow summer squash
- Yellow tomatoes
- Yellow Watermelon
- Lemon
- Pears
- Pineapple
- Sweet corn
Green Foods
Remember back to seventh-grade science and learning about photosynthesis? A major part of this process included the pigment chlorophyll, the substance responsible for giving edible and inedible plants their green color.
Chlorophyll-rich foods exert profound healing and offer other protective assets like antioxidants that function to cleanse the blood, detox tissues, balance body pH, boost cognitive acuity, energize, and bolster the immune system. Hence why green veggies are typically the most encouraged.
Specifically, green-colored foods are rich in isothiocyanates, compounds that catalyze liver enzymes that help remove carcinogenic substances (toxins). They’re also potent sources of vitamin K, folic acid, potassium, carotenoids, and omega-3 fatty acids.
In contrast to red, orange, and yellow plants, green plants preserve their nutritional content better when eaten raw. Additionally, the more vibrant green they are, the more nutritious they are. For example, spinach is much more nutrient-dense than iceberg lettuce.
Eat plenty of these green foods (throughout the entire year and not just on St. Patrick’s Day!):
- Green apples
- Green beans
- Green cabbage
- Green grapes
- Green onions/chives
- Green pepper
- Greens/green supplement powders
- Green tea
- Artichokes
- Arugula
- Asparagus
- Avocado
- Bok Choy
- Broccoli
- Brussel sprouts
- Cucumber
- Honeydew melon
- Kale
- Kiwi
- Lettuce varieties
- Limes
- Peas
- Pistachios
- Seaweed
- Spinach
- Sprouts and microgreens
- Wild edible greens
- Zucchini
Blue Foods
Blue foods derive their color due to anthocyanins and like green foods, the darker the blue the higher the phytochemical and nutrient concentration.
Anthocyanins are powerful antioxidants that are particularly heart-healthy because they prevent clot formation. Indeed, wild blueberries and blackberries are widely known as the most potent antioxidants in the world.
Furthermore, anthocyanins generally protect all cells from damage, support healthy blood pressure, prevent unnatural clot formations, and improve memory recall. They also work to lower the risk of many cancers and promote healthy aging in general.
Eat blue to fend off the blues of chronic disease and low quality of life due to poor health.
- Blue spirulina and/or chlorella
- Blackberries
- Blueberries
- Wild blueberries
Purple Foods
Exceptionally similar to blue foods, purple fruits, and veggies achieve their color because of the potent anthocyanins. Purple foods also contain flavonoids that help make blood vessels healthy, reverse short-term memory loss, improve motor skills and prevent bacteria from sticking to cells.
In addition to nutrient content, the richness of the purple color also indicates their ripeness. However, they go hand in hand because fruits and vegetables are their most nutrient-dense when they’re ripest. This is a major reason why it’s recommended to eat seasonally!
Vibrant violet foods include:
- Purple banana blossoms
- Purple grapes
- Eggplant
- Figs
- Juneberries
- Plums
- Prunes
- Raisins
White/Beige/Light Foods
Although non-plant, typically man-made foods are brown or white-ish in color, a few healthy fruits and veggies are also colorless but still provide nutrient value.
As mentioned, white and very light brown foods derive their color from the phytochemical anthoxanthin. Many also contain the chemical allicin, which is associated with lowering cholesterol and blood pressure and reducing the risk of certain cancers and heart disease. Additionally, many white, light-colored foods are rich in potassium, a nutrient that supports a healthy heart and kidneys and muscle contraction.
- Bananas
- Cauliflower
- Garlic
- Ginger
- Jicama
- Most varieties of mushrooms
- Onions
- Parsnips
- White Potatoes
- Turnips
Black Foods
Last but not least, there are some functional black foods. Often considered the underdog of healthful foods, many black foods are rich in antioxidants and other phytochemicals that have healing and health benefits. Like blue and purple foods, they contain anthocyanins, which are not only anti-inflammatory but anticarcinogenic and antiviral too.
While black beans are the most obvious food within this category, other very unique ones include:
- Activated charcoal (only take with the supervision of health practitioner due to its medication interactions)
- Black garlic
- Black rice (sometimes called purple rice)
- Black seed oil
- Black sesame seeds
- Black beans
- Chaga mushrooms
- Chia seeds
- Pepper (enhances the absorption of curcumin/turmeric)
In Summary
Plants are literally considered healthful because of their vibrant colors, which translates into nutrient density, ripeness, and value. And it’s vital to eat a variety of colors to reap the effects of different nutrients. To recap, the different colors and their main value and function include:
- Red (betalains, carotenoids, and anthocyanins): antioxidant, anticarcinogenic, antimicrobial, and antilipidemic
- Orange (carotenoids): vision, heart, skin, and bone health
- Yellow (carotenoids): sun protective
- Green (chlorophyll): antioxidant, anticarcinogenic, detoxifying, energizing
- Blue (anthocyanins): potent antioxidant, anti-aging, heart health
- Purple/Violet (anthocyanins): potent antioxidant, antibacterial, heart health
- Black (anthocyanins): anti-inflammatory, anticarcinogenic, antiviral
- White/beige/light (anthoxanthins): lower risk of chronic disease, promote heart, bone, and muscle health
How colorful can you make a rainbow dish?
References:
Anthony K. Carotenoids: Everything You Need to Know. Healthline. Updated September 18, 2018. www.healthline.com/health/carotenoids.
Health Benefits of Chlorophyll-Rich Superfoods. Superfood Evolution. www.superfoodevolution.com/chlorophyll.html.
Mangieri H. Plant Pigments – the Bioactive Compounds That Give Color to Fruits and Vegetables. Heather Mangieri Nutrition. Published August 21, 2020. heathermangieri.com/plant-pigments-the-bioactive-compounds-that-give-color-to-fruits-and-vegetables/.
Rutherford-Fortunati A. Phytochemicals: Eating from the Rainbow! Gentle World. Published April 15, 2014. gentleworld.org/phytochemicals-eating-from-the-rainbow/#Health%20Benefits%20of:%20White%20Fruits%20and%20Veggies.
Schaeffer J. Color Me Healthy – Eating for a Rainbow of Benefits. Today’s Dietitian. Published November 2008. www.todaysdietitian.com/newarchives/110308p34.shtml.
Wasserman M. Health Benefits of Black Foods. Sunwarrior. Published May 27, 2019. sunwarrior.com/blogs/health-hub/health-benefits-of-black-foods.
