top of page

Colorful, Plant-Based Food: Eating the Rainbow

Everyone has their favorite diet. Experts argue which is more effective. The meat group has a fan-base and certainly so does the vegan life-style. What really doesn't receive any argument is the value in eating fruits and vegetables. The very well-studied Mediterranean diet is a huge proponent of eating plant-based foods, as is the #vegan and vegetarian approaches, the hunter-gatherer diet or Paleolitic, and even the ketogenic diet. Plant-based diets reduce a plethora of chronic disease including cardiovascular disease, diabetes, cancer, dementia, and obesity. Despite this agreement, people just aren't eating sufficient plants.

Phytonutrient Gap

Only nine percent meet the daily recommendations for fruits and vegetables in the United States in a 2015 survey and popular NHANES survey found eight out of ten Americans fall short in every color of phytonutrients, especially the color category of purple and blue foods which eighty-eight percent of people neglect to meet (Minich, 2019).

Many leading agencies have attempted to better encourage eating "the rainbow," emphasizing the vitamin K offered from green vegetables and the vitamin A from our red and orange vegetables. They have advocated for approximately 2 cups of fruits each day and three cups of vegetables daily. A mere 600 grams of plant-based foods can decease your risk for cancer (Minich, 2019). The polyphenols and other phytochemicals are thought to offset the danger of eating pollutants, further buffering our risk for disease.

What you may not realize is plants have been associated with a sense of psychological well-being. Studies have found that eating eight cups of fruits and vegetables daily is positively associated with #happiness and overall life satisfaction, to the extent that the improvements were equal in measure to the psychological impact of transitioning from unemployment to employment. Curiosity and creativity are also enhanced in those who eat more fruits and vegetables.

Fruits and vegetables have long been credited with their antioxidant activity but this term has really been abandoned because experts now appreciate the much larger and functional role of phytonutrients. They are now recognized as cell signaling agents, messengers, and have the ability to modify telomerase activity, as well as partake in the epigenetic changes through histone modification and demethylation. Experts are now considering the potential for polyphenols to be a potential neutraceutical in the treatment of type 2 diabetes.

Fruits and vegetables have gained such credibility and their complex impact on our health in just the last few years that they aren't simply carbohydrates or fiber numbers anymore. They have their own phytochemical index which evaluates individual fruits and vegetables for their flavonoids, proanthocyanidins, isoflavones, and carotenoids, which cumulatively give a better estimate of a food's phytochemical content. A higher phytonutrient index is associated with weight loss and most especially reduction in overall body fat, as well as improved lipids, lowered hypertension, and lower incidence of breast cancer (Minich, 2019).

Anthropologic Thoughts

It is thought that the diets of those nearly 135,000 years ago consisted of more than 3,000 species of plants compared to today's diets with only 400 gathered plants and only about 100 of those are consumed as food. The greater the variety of fruits and vegetables we consume, the more significant the health impacts including lowered blood pressure, less oxidative stress, and even fewer falls than those eating a diet with less variety. When I test the gut microbiome on clients, I often find even among those with high colony counts, that their diversity is very limited. This is why I recommend choosing a new probiotic with each new bottle.

Plants are recognized by their deep pigmentation and often their phytonutrients fit a specific category based on their color; for example, foods rich in beta-carotene are often orange and foods with an abundance of chlorophyll often are green, and purple foods often have a high content of flavonoids. These specific (phyto)nutrient attributes address specific categories of health dis-ease. Researchers have starting recognizing fruit and vegetable groups which correspond to these specific phytonutrient properties and the specific color of plant foods they most often originate. This is incredibly cool to me, and can I say, midwives have known this for generations!

Red Foods Improve Inflammation

Cherries, rosehips, red bell peppers, and tomatoes have some of the highest amounts of vitamin C which is well known for improving the immune system and decreasing #inflammation. Several studies now have demonstrated that red-colored foods may assist with reducing systematic inflammation and bolstering immune status by reducing infections. Consider watermelon, apples, cherries, cranberries, pomegranate, and raspberries if you suffer from chronic disease.

Tomato juice has been independently studied, and alone, they have also showed beneficial effects on inflammation and even metabolic syndrome when taken four times a week for two months. Interestingly #tomato juice consumed alongside a high-fat meal was affective at reducing inflammation that otherwise would have resulted from this type of meal, and lowered total cholesterol, triglycerides, and several cellular and plasma inflammatory markers, as well as increased the HDL (good cholesterol). Tomatoes are especially effective at reducing inflammation and oxidative stress.

Strawberries are another star among the red foods. They have shown to reduce after dinner increase in inflammation, especially if the strawberries were consumed in a drink prior to the meal. Obese adults with knee osteoarthritis drank a freeze-dried strawberry beverage in one study for twelve weeks and their inflammatory bio-markers and cartilage degradation were reduced. Strawberry supplementation has reduced constant, intermittent, and total pain which has led researchers to consider them as significant analgesic and anti-inflammatory options for obese clients who suffer with knee osteoarthritis. In another study, strawberries prior to meals for just six weeks reduced cRP (inflammatory marker) and this was repeated in a third study, which also found lower blood sugar concentrations six hours after the meal. Freeze-dried strawberries appear to mitigate the inflammatory response over time and following meals.

Beets are potent, particularly in a compound called betalains which have been heralded as important for chronic diseases involving inflammation, oxidative stress, and dyslipidemia (high cholesterol). Another study found beets to reduce hypertension. I so wish I could articulate to you how really cool I think these findings are and how much it makes me want to get out into nature and show it my gratitude! We really were created to live in harmony with the earth. I can't say it enough, how health is completely dependent on our relationship with Mother Earth. Get your feet in the dirt. Let the sun shine on your face. Eat plants daily. Soak in salt water. Soak up balancing ions when hugging a tree.

Orange Foods and your Reproductive Health

Similar to red foods, orange-colored fruits and vegetables offer significant antioxidants but the biggest difference between the two is the amount of carotenoids this class of foods offers. Carotenoids are fat-soluble antioxidants which means they are stored in our adipose tissue. Interestingly, it appears based on the location of where they are stored, that orange foods act more on our reproductive system. Inflammation can impact infertility, and up to fourteen different carotenoids have been discovered in ovarian tissue. Research has demonstrated that even short-term beta-carotene can enhance or modulate ovarian function and progesterone synthesis. Furthermore (am I kinda blowing your mind), beta-carotene may have endocrine-stimulating or modulating effects as shown in prepubertal goats. Longitudinal studies have even found dietary carotenoids to be associated with a reduced risk of insulin resistance (Minich, 2019).

Studies evaluating beta-carotene levels in blood, follicular fluid, and in the corpus luteum were highest during pregnancy and this level corresponded to the weight and diameter of the corpus luteum. Fascinating! There is also evidence in line with this that demonstrated women with endometriosis are more likely to have a lower intake of vitamin A than those without endometriosis. Supplementation with beta-carotene and other antioxidants in women has shown to reduce time to pregnancy in couples treated for unexplained fertility (Minich, 2019).

These benefits aren't limited to women; men benefit too! Sperm concentration is improved with optimal beta-carotene and in another study, those with lower antioxidants in their seminal plasma had higher rates of infertility.

Wild yams have long been known for their support of menopausal symptoms and studies have demonstrated their hormone balancing potential. They are full of phytoestrogen and have demonstrated ability to stimulate the ovarian estradiol synthesis while decreasing genotoxic estrogen. Wild yam products are commonly used in the dietary supplement industry for enhancing progesterone levels.

Carrots have also been associated with estrogen metabolism and lower rates of both breast and prostate cancer. Studies have also offered an implied association with ovarian health based on animal studies, perhaps related to the concentration of carotenoids in the ovary.

Orange fruits, including mandarins, oranges, tangerines and even papaya, peaches, and persimmons offer vitamin C and bioflavonoids. A higher consumption of these orange fruits has been associated with lower rates of endometriosis and that eating as little as about 400mcg of B-cryptoxanthin per day from orange-colored fruits can delay your natural menses by more than a year. Oranges play a significant role in reproductive health.

Yellow Foods and Digestion

Again, there is so much to gain from eating a plant-based diet and yellow fruits and vegetables offer a plethora of benefit, but it is their association to the gastrointestinal tract I find particularly intriguing. The bioflavonoids in yellow foods have been found to modify gastric microbial activity including H. pylori, and a tendency towards ulcers. Yellow foods also support the efforts of our cytochrome P450 enzymes which can modify the intestinal and hepatic detoxification efforts of toxic compounds! (You might get all exclamation points from here on out; this is so exciting!!!) Yellow foods are soluble, insoluble, and prebiotic so they can minimize the consequence of eating simple sugars, improving your glycemic index, and they feed your gut microbiome (Minich, 2019).

Ginger is a rhizome that contains over 400 different chemical compounds, and so many studies have been done on this earth medicine because he really has demonstrated phenomenal outcomes for nausea, vomiting, dyspepsia, and even irritable bowel syndrome. Ginger and artichoke together can promote gastric emptying.

Lemons are acidic and this low pH helps our digestive health. Lemons can lower our glycemic index by half when eaten with starch-rich meals. This is huge! Citrus fruits have been linked with fewer gastric ulcers and reduced risk of esophageal and gastric cancers. Lemons is very advantageous for diabetics, and really should be the go to for any gastrointestinal complaint.

Pineapple helps metabolize undigested food and has even been used preoperatively to eliminate remnants in the stomach and improving colon cleaning prior to a colonscopy. Bromelain, derived from pineapple, is often isolated for application in dietary supplements marketed for enzymatic activity.

Bananas and plantains are excellent prebiotics in the gut, and have been shown to increase bifidobacteria counts and ultimately, less bloating compared to controls. Plantains and bananas (and even pineapples) are highest in serotonin content and knowing that many neurotransmitters are formed in the gut, the implications of this interaction - diet and our neuroactivity - I can't even image what future science will unfold for us.

Green Leafy Vegetables and Cardiovascular Health

Leafy greens are especially abundant in their beneficial heart nutrients, including vitamin K, magnesium, potassium, naturally occurring nitrates, and folates. A large meta-analysis found that if - okay, sit down for this one - if we consumed green leafy vegetables almost every day, we could reduce cardiovascular disease by more than fifteen percent! Hypertension, coronary heart disease, and stroke have also been reduced by daily consumption of green vegetables due to their polyphenol concentration and their variety of polyphenol subclasses, which may differentially affect cardiometabolic risk factors. Flavonoid antioxidants such as vitexin and others have cardioprotective effects, particularly Swiss chard (Minich, 2019).

Spinach has copious amounts of nitrates which are excellent for vascular health and reduces mortality from cardiovascular mortality. Nitrates promote nitric oxide bioavailability, reduces systemic blood pressure, enhances blood flow to the tissues, modulates muscle oxygen utilization, and improves exercise tolerance. Celery, cress, chervil, lettuce, spinach, and rocket. This can be achieved in as little as one week of daily intake as well!

Cruciferous vegetables are where we get the biggest bang for our buck though. These benefits are quite profound for the cardiovascular system, and these particular vegetables can help prevent platelet aggregation and reduce thrombus formation, but these vegetables are also incredible for optimizing our detoxification processes.

Blue-Purple Foods and Cognition

Blueberries and grapes, full of polyphenols, flavoinds, procyanidins, phenolic acids and derivatives of stilbenes have been shown to inhibit cancer cell proliferation, reduce platelet aggregation and lower cholesterol. Concord grapes improves memory function in adults who have mild cognitive impairment and in healthy mothers, spatial memory and driving performance were improved. Attention and a sense of calm have also been improved in twenty year old adults.

Blueberries improve cognitive tasks, such as completing mazes, reducing repetition errors, improved recall, accuracy on high-demand cognitive trials with increased interference at three hours, and overall slower cognitive decline delaying cognitive aging by up to 2.5 years. Blueberries have also shown to improve mood in both children and young adults. Cell survival and neuroplasticity appears to improve when berries are in the diet (Minich, 2019).

Counting Colors rather than Calories may be More Effective

Using a checkbox list or even crayons to mark your daily colors, aiming for a rainbow of colors, may offer greater health benefits and implement long-term lifestyle changes than monitoring calories. Students increase their propensity to choose vegetables when they have greater options. Gardens in schools are a strategy for implementing these concepts. Adding seasoning, spices, herbs, blended fruits and vegetable drinks, herbal teas, fruit-and-vegetable-infused waters, juices, and whole-food powers are additional ways to increase diversity of fruits and vegetables in the diet. Eating more meals at home and following a Mediterranean diet can improve our overall fiber and colorful plant-based consumption. The real pivotal move though, is finding adequate support. Role modeling by parents makes a difference in the diets of their children.


19 views3 comments


I didn't realize how different colored foods could have different impacts on our lives. What exactly about the colors make them affect us differently?


Dr. Penny Lane
Dr. Penny Lane
Oct 10, 2020

Did you see that freeze-dried strawberries were particularly helpful? Admittedly, I am not sure where you'd even find those, but I suspect a Whole Foods might have them. I'll have to peek myself. My kids love broccoli, but I don't cook it near as much as I should. That's the one I am eager to up in my diet as its incredible for assisting in phase two of the detoxification process -- find out more by joining my detoxification program!


This is a wonderful blog post that sheds light on the ideas of the value of plant based foods in our life. I am very blessed that i love all fruits and veg and I've never been one that wont eat them. However, like all Americans as you outlined I am sure i do not eat the recommended amounts but I'm close as i eat 2-3 cups veg everyday and i try to make sure one cup is dark greens. However, because I try to keep my carbs below 24 g per day its very hard for me to eat fruits. However, after learning of how strawberries can help my inflation I think i will look for supplements to help…

bottom of page