Eating the rainbow: why eating a range of colourful plants is key for optimal health

We all know to eat our greens but what about the red, orange, yellow, green, blues and whites?

“Eating the rainbow” means including an abundance of plant based foods from each of these 6 colour groups, and provides the foundation of nutrients needed to restore your health, whatever the health issue.

The colour in plant foods is where the magic happens!

The colours are the sources of powerful phytonutrients – hundreds of different chemicals that benefit a wide range of chronic diseases and stimulate enzymes that help the body reduce inflammation, balance the immune system, and support heart, skin, liver, brain, hormonal health, and even stimulate the death of cancer cells.

Phytonutrients in foods come in different colours: red, orange, yellow, green, blue/purple/black and white/tan/brown. Each colour in plants is caused by specific phytonutrients, and so eating the whole rainbow of colours provides us with the full range of phytonutrients, vitamins, minerals, and antioxidants that allow our bodies to heal. Vegetables, fruits, nuts, seeds, herbs, spices, legumes, whole grains and teas are rich sources of phytonutrients.

Eating the Rainbow is the first step towards a healthy way of eating.

The nutrients contained in colourful plants are good medicine for chronic disease prevention and treatment.

I recommend aiming for at least one, and ideally two servings of plant based foods of each colour every day! And remember to eat different foods each day – it doesn’t count if you eat the same ones, day in and day out. Remember, diversity is one of the cornerstones of a healthy diet.

For a 28-day practical exploration of colour and its wisdom and it’s benefits for our mental and physical health, you may want to explore my “28 Days of Living a Colorful Life” program:

Red foods can be anti-cancer, anti-inflammatory, supporting immune, prostate, and heart health. There is a wide choice of red foods so why not try something you are not familiar with, such as pomegranate or goji berries. Keeping the skin on red-skinned foods, like potatoes, apples, and onions will provide you with more of the essential phytonutrients.

Tomato, watermelon, pink grapefruit and guava are rich in an important phytonutrient called lycopene that may protect against cancers of the prostate, breast, and skin, and reduce the risk of heart attacks. It is found in tomato based products such as tomato juice, tomato pasta sauce, and tomato paste. This red phytonutrient becomes more available to the body when the plant is heated and when combined with some fats (it is a fat soluble nutrient). A good source of lycopene may therefore be a cooked tomato sauce with extra-virgin olive oil added.

Anthocyanins are phytonutrients you can find in red berries such as cherries, raspberries, strawberries, cranberries, and in other red foods like apples (with skin), beets, cabbage, onion, and kidney beans. They help with reducing the risk of cancer and protecting the heart and brain.

One way to eat more red foods is to add fresh tomatoes, goji berries, raspberries, pomegranate seeds, or pink grapefruit sections to your green salads.

Orange foods help protect the immune system, eyes, and skin, and reduce the risk for cancer and heart disease. There are many foods in this group, that you can easily include in your diet. Many of them are fruit or starchy root vegetables which can be eaten with some healthy fats and protein to reduce the spike in blood sugar.

When you think of carrots, you may think of their link to eye health (and seeing in the dark?). This is because they are rich in beta-carotene which the body can  turn into Vitamin A. Vitamin A has many functions in the body including supporting the immune system and reducing inflammation, skin and eye health. It’s a powerful and under-estimated nutrient which is essential to full-health.

Unfortunately, it may not be enough to rely on beta-carotene and other carotenoids as your sole source of Vitamin A. This is because our ability to convert carotenoids into Vitamin A depends on our genetics, as well as digestive and other issues. Food sources of Vitamin A, rather than beta-carotene, include seafood, eggs, full-fat dairy such as yoghurt, keffir, milk and cheese. If you are vegan, then you particularly need to focus on orange coloured vegetables! And again, cooking vegetables makes the carotenoids more easily absorbed by the body and they are best absorbed when eaten with some healthy fats.

Bioflavanoids are another phytonutrient that work with Vitamin C to reduce the risk of heart attacks and cancer, and help maintain strong bones and teeth, healthy skin and good vision. It is common in nature to see vitamins and phytonutrients working together to have the best effect on the body. Bioflavonoids are found in oranges, grapefruit, tangerines, peaches, nectarines, lemons and pineapple. In contrast to beta-carotene, they are best absorbed by the body when not cooked.

An easy way to get some orange foods is to add the spice, turmeric, to your stir-fry or curry or to drink turmeric latte (golden milk).

Yellow foods are beneficial because they contain phytonutrients that are anti-cancer, anti-inflammatory, and may protect the brain, heart, eyes, and skin. Remember to eat a variety of yellow food (not just bananas and potatoes!). You might also notice that many of these foods, such as potatoes, banana, and corn are starchy so remember to eat them with some protein and good fats to blunt that blood sugar spike!

Like lycopene and beta-carotene, lutein and zeaxanthin are both carotenoids. They are anti-oxidants, protecting your cells from damage, and are most well known for supporting eye health. A good source is corn, but make sure to eat corn on the cob, or whole kernels, rather than processed foods. Again, these phytonutrients are fat-soluble and are more available to the body when cooked so adding some butter to that corn on the cob may be better than with no butter at all!

An easy to get some yellow into your diet, is to grate ginger into stir-frys or to drink fresh ginger tea. Ginger is anti-inflammatory and supports a healthy balance of gut bacteria.

Green foods support our health as they contain phytonutrients that are anti-inflammatory, anti-cancer, support hormonal balance and liver detoxification as well as the brain, heart and skin.

We all tend to think of green foods as healthy and there is no shortage of choice, but surprisingly, most people eat too few of them. Olives and avocados are two foods which should be singled out for their health promoting benefits.

Avocados are an amazing food, with 1 avocado containing 9 grams of fibre and more potassium than a banana. One scientific study showed that eating a hamburger by itself led to an increase in inflammation in the body within hours after it was eaten. However, when just half of an avocado was eaten together with the hamburger, there were no increases in inflammation.

Olives and extra-virgin olive oil are anti-inflammatory and anti-oxidants, helping the cells in our body to function optimaly. They are helpful in keeping heart and blood vessels healthy and protecting against heart disease.

Cruciferous vegetables, such as rocket, bok choi, kale, watercress, brocolli, cabbage and brussel sprouts, help the body balance hormones by supporting the liver to clear toxins. The class of phytonutrients that do this are the glucosinolates and this nutrient gives these vegetables there sulphur-ish smell. When these cruciferous vegetables are chopped or chewed, they are turned into isothiocyanates (indole-3-carbinol, sulforaphane, and many others). These phytonutrients change the way that estrogen is metabolised so that it can be cleared from the body in a healthy form, and may reduce an excess of estrogen. This is how these vegetables are thought of as anti-cancer, and eating these vegetables is associated with a decreased risk of estrogen dependent cancers such as breast and uterine cancer. Eat these vegetables lightly steamed to retain their nutrients.

Phytosterols, contained in avocado, olive oil, rice brain oil and sunflower seeds (one of the richest sources at 374mg per 1/2 cup serving), have been found to help reduce LDL-cholesterol and are now also sold as supplements – but you can also just focus on the foods that contain them.

Catechins are the bitter compounds found in green tea and Matcha. The most famous catechin from green tea is called epigallocatechin gallate (or EGCG). They are potent anti-oxidants and one study found having just one cup of green tea a day reduced breast cancer risk by 50%. Green tea contains about 2/3 of the caffeine of black tea, but decaffeinated versions are also available.

These dark coloured plants are beneficial as they contain compounds that are again, anti-inflammatory and anti-cancer, and protect the brain and heart, and support healthy ageing. They are the colour group that most supports healthy cognition and memory.

Unfortunately, as there aren’t as many options in this colour group, many people do not eat enough of these foods, but there are some great options: The blue/purple/black fruits include a wide variety of berries: blueberries, blackberries, and boysenberries. Remember, most of the phyto-nutrients are in skin and the smaller the berry, the more nutrients it will contain. Purple varieties of common fruits and vegetables are also becoming more widely available: purple carrots, cauliflower, cabbage, potatoes, kale, grapes, and rice, and these varieties are likely to be more nutrient dense than the regular versions. With a little thought, it is possible to eat from this colour group daily.

Resveratrol is a phytonutrient that is now well know for its beneficial affect to promote healthy ageing and reduce inflammation, balance blood sugar and support heart health. It can be taken as a supplement but small amounts are available in foods such as grapes (in the skin), dark chocolate and blue berries. Some is contained in wine but to get 500 mg of resveratrol, you would need to be drinking 40 litres of wine daily – probably not practical ;)

When we think of this colour group, foods such as bread, bagels, cookies, crackers, and pasta may come to mind. But these aren’t the types of whole foods that contain the phytonutrients we are talking about here. This group includes nuts and seeds, legumes (such as chickpeas, mung beans and lentils), whole grains, the super anti-inflammatory ginger, apples – another super food for the gut, as well as coconut and coconut products.

Dates can be used rather than a processed sweetener. Garlic, onions and shallots are all part of a sulphur rich family called Alliums. They have many health promoting effects including and protecting against heart disease, cancer, inflammatory diseases and if you tolerate these foods, they may help balance the bacteria in your gut.

Dark chocolate is also on this list and is a healthy choice if it is 70-85% cacao and is eaten in moderation. Cacao contains plentiful anti-oxidants and may support the brain and heart, as well as give us a little lift!

Allicin from garlic is anti-bacterial and anti-viral as often used to improve gut health. It’s also anti-cancer and can lower blood pressure. To maximise the allicin content of your garlic, leave your chopped or crushed garlic for 5-10 minutes before cooking.

Lignans act as anti-oxidants in the body and are phyto-estrogens i.e. they have a weak estrogen like effect in the body. Lignans are anti-inflammatory, promote healthy blood vessels, and act as anti-cancer agents, especially against hormone related cancers like breast and prostate cancers. Flax ]is the food that contains the most of these lignans, containing 7 times as much lignan as the next runner-up food, sesame seeds. I recommend ground flax seed as it is better absorbed by the body the whole flax seed – you can grind the seeds yourself in a coffee grinder to get the freshest possible ground flax seed.