Rainbows are as prevalent in Hawaii as Hula and the Aloha Spirit, but eating the rainbow-the colors of the rainbow that is-is an intuitive approach to a healthy diet that goes back thousands of years. Most likely, the oldest philosophical and medical system on earth is Five Elements Theory, originating in China and dating back over 5,000 years. It differentiates five distinct energies in nature that interact with each other, and just like in yoga practice, the emphasis is on their balance and harmony in the human body in respect to health and well-being. The five elements are each named according to a naturally occurring element that expresses their essential energies: Wood, Fire, Earth, Metal, and Water. As a medical paradigm, each element corresponds to a biological system in the body and an associated color. The colors are green, red, yellow, white, and deep blue or black. It was seen as beneficial to strive for a balance of these colors in all aspects of life, and especially in our diet.
The Five Element paradigm is much more sophisticated than this brief introduction can express, and it is still used in Feng Shui and Traditional Chinese Medicine. Here we are exploring how it holds up to modern science. Is there evidence that simply eating a color-balanced diet could not only be healthy, but also possibly sufficient and complete? Let’s take a look.
For starters, the headlining slogan on the American Heart Association’s “Healthy Eating” page reads, “All the Colors, All the Time.” Equally, The American Institute for Cancer Research recommends eating plenty of unrefined plant-based foods of different colors in order to harness the full “protective power of plants.” While the benefits of a color-balanced diet pertain to all food groups, here we are focusing on a predominantly plant-based diet.
Certainly it is not new to anyone that eating fruits and vegetables is healthy, but research into the relationship of colors and phytochemicals can now explain why variety and balance is critical and integral to good health and disease prevention. Phytochemicals, or plant chemicals, are produced by plants as a means to protect their own health, and fortunately many can protect ours as well. According to nutrition researchers more than 4,000 phytochemicals have been identified so far, of which about 150 have been studied in depth. With this vast quantity of potential nutritional gems, it seems obvious and important to aim for a balanced variety in our daily diet. The respective colors of plant foods represent different phytochemicals, and “Eating the Rainbow” provides us with a simple and intuitive blueprint to achieve this aim.
Green: Green vegetables contain chlorophyll, isothiocyanates (such as sulforaphane), and indoles just to name a few. Numerous studies have shown that these phytochemicals have the potential to lower the risk of some cancers as well as support the liver in its detoxification pathways. Just published in May of this year, a study from Harvard Medical School showed that the compound indole-3-carbinol (I3C) found in broccoli and other cruciferous vegetables can suppress tumor growth and deactivate a gene known to play a role in a variety of common cancers.
Red: The Red group contains phytochemicals such aspolyphenols and lycopene. Lycopene, which is particularly abundant in tomatoes, acts as an antioxidant in your body to protect your cells from damage. Lycopene has been shown to protect against heart disease, inflammation, arteriosclerosis, infections, and cancer, especially prostate cancer.
Yellow: Yellow and orange fruits and vegetables are rich in carotenoids (including lutein) and bioflavonoids, which are shown to help maintain vision health, heart health, a strong immune system, and a lower risk of some cancers. Gingerol is the main bioactive compound found in our favorite golden root ginger and may be responsible for much of its medicinal properties. Studies show it has powerful anti-inflammatory and antioxidant effects and that it benefits digestion in numerous ways.
White: White plant foods tend to be high in allicin, quercetin, and polysaccharides. These can benefit the immune system and cholesterol and blood pressure levels, thus lowering some risks of cancer and heart disease. Quercetin, found mostly in onions, garlic, and apples, is an antioxidant and natural antihistamine, shown to benefit lung health and reduce allergic symptoms. According to researchers in a 2014 Journal of Infectious Diseases & Preventive Medicine study, quercetin can be “a promising treatment for the common cold” because of its potential to prevent the virus from exerting effects on the body.
Black: Black, blue, and purple foods contain flavonoids (such as anthocyanins) and ellagic acid. These help memory function, protect cells from oxidation, and also lower the risk of some cancers. Studies have also found that in addition to reducing the risk of cognitive damage and slowing cognitive decline in older adults, blueberries (high in anthocyanins) can also improve a person’s short-term memory and motor coordination. Much like cranberries, blueberries may also prevent urinary tract infections. A study published in the New England Journal of Medicine suggests that specific compounds found in blueberries, called proanthocyanidins, prevent bacteria from sticking to the walls of the urinary tract.
Now, what I found particularly intriguing about summarizing these nutritional findings and ancient wisdom into the simple concept of “Eating the Rainbow” was a beautiful experience that happened 16 years ago. At the time, my husband and I were introducing Oriental Medicine and Acupuncture to the cruise industry in cooperation with Celebrity Cruise Lines. Besides offering treatments, we lectured on a variety of health topics, among them the “Five Elements Diet”, making our case for the simplicity and potency of this approach.
The stunning and somewhat unexpected effect of our lectures was that, on every cruise, we had scores of passengers come by our dining room table to proudly and happily show us their carefully color-balanced plates. This was immensely moving and gratifying. The best healthy diet after all, is the one that is actually adopted and enjoyed.