Why eating the rainbow is so important and how to get the most out of all the colours
It’s no secret that we should be eating plenty of vegetables. We all know it and yet it’s pretty easy to go a full day with little to no vegetables on your plate. For most people, vegetables act as the friendly sidekick to the main meal when in fact they should be the hero.
Vegetables are THE superfoods you need in your diet every day and in as many meals as possible.
As you’ve likely heard, they’re loaded with dietary fiber and micronutrients that keep the body functioning and thriving.
Dietary fiber fills you up, slows down absorption of nutrients into the blood stream, which keeps you satiated longer and helps keep your blood sugar stable. It also speeds up elimination and toxin removal from the body and fuels the good bacteria that keeps your gut healthy, which in turn boosts our immunity, balances your hormones, and stabilizes our cholesterol. I could go on, but I think you get the point. Dietary fiber is extremely important.
We should be aiming to get 25 - 30 g of fiber per day but most of us struggle to get even half of that.
Filling half your plate with colourfull vegetables is the easiest way to add fiber to your meals while benefiting from a host of phytonutrients, chemicals naturally found in plants that determine their colour, flavour and aroma while protecting them from harm like fungus and bacteria.
Every colour group has something unique to offer
The more variety and colours of vegetables you eat the more you'll benefit from nature's goodness which is why we are often told to "Eat the Rainbow".
Here's a look at my top choices from the produce aisle and why they are so important.
The Green Group - Dark Leafy Greens
Dark leafy greens are a powerhouse of nutrients and the darker the greens the better. They are loaded with micronutrients like vitamins C and K and the minerals calcium, magnesium, potassium and iron.
If you're a woman and have ever considered getting (or been) pregnant, you'll be familiar with Folate, a B vitamin that helps prevent birth defects. Dark leafy greens are one of nature's most abundant sources of Folate, which also regulates many bodily functions including red blood cell formation, the conversion of carbohydrates into enery and the metabolism of amino acids, the building blocks of protein.
Studies have shown that dark leafy greens are also a good source of some carotenoids, antioxidant nutrients that work to prevent free radical damage and oxidative stress, basically helping fight the physical and mental signs of aging, inflammation and potentially even cancer. Beta-carotene, a carotenoid found in dark leafy greens (also abundant in yellow/organge plants like carrots and squash), is converted to Vitamin A in the body, an essential nutrient for eye sight, brain, immune and reproductive function.
Add these to your weekly market haul:
Kale, Chard, Spinach, Collard Greens, Beet Greens, Arugula, Valerian Greens, Bok Choy, Mustard Greens, Dandelion Greens, Watercress, Mizuna, Cicory and Dandelion.
Preparation tips and techniques:
Perserve the delicate nutrients in your leafy greens by eating them raw or gently steaming or sauteeing them until slightly wilted. When adding leafy greens to cooked dishes, do so at the very end. Wash, dry and chop your leaves into bite size pieces and stir them into the pipping hot dish after you've removed it from the heat. Cover it with a lid and allow the greens to cook gently for 2 to 3 minutes. Be sure to serve your greens with a source of fat for optimal absorption of the fat soluble vitamins (like Vitamins A and K) and an acidic medium like lemon or vinegar for increased absorption of minerals (like iron and calcium).
Cruciferous Vegetables
The Brassica family of vegetables is another powerhouse you'll want to keep on hand. Many of the dark leafy greens mentioned previously (kale, collard greens, mustard greens, and watercress) are also a member of the cruciferous family of vegetables.
For simplicity, I’ve lumped these into the green group, eventhough some of the vegetables in this group come in other colours (i.e. cauliflower is white with orange and purple varieties, cabbage comes in both green and purple/red, while chard comes in a rainbow variety).
In addition to the multitude of nutrients cited above, some cruciferous vegetables like broccoli and kale also contain Sulforaphane, a powerful molecule that has been said to prevent cancer, stimulate the immune system yet calm inflammation, induce phase II liver detoxification and act as an antioxidant.
Add these to your weekly market haul:
Broccoli, Cauliflower, Brussels Sprouts, Cabbage, Kale, Mustard Greens, Collard Greens, Kale, Bok Choy, Kohlrabi, Turnips and Watercress, Mizuna, etc...
Preparation tips and techniques:
Chewing raw cruciferous vegetables is the best way to activate sulforaphane, since it’s destroyed in cooking. However, you can still reap the benefits by serving the cooked vegetables with mustard seed powder. This is especially important if you have trouble digesting raw cruciferous vegetables or have thyroid issues. Cooking will make them easier to digest and will reduce goitrogens, which can interfere with iodine intake by the thyroid and make preexisting thyroid conditions worse. Overall though, there is no need to worry about goitrogens unless you have a preexisting thyroid condition, iodine deficiency and are consuming excessive amounts of kale smoothies every day.
The Blue & Purple Group
Blue and purple fruits and vegetables are known for their rich antioxidant content and for very good reason. Antioxidants protect our cells from damage caused by free radicals, unstable molecules that seek stability by stealing electrons from other molecules, damaging some cells permanently, and creating more free radicals in the process.
That's because antioxidants have the ability to stabilize free radicals, without becoming unstable themselves, to prevent oxidative stress.
Oxidative stress happens when there are too many free radicals in the body and not enough antioxidants to contrast them. Free radical formation happens naturally but outside influences like exposure to environmental toxins, poor dietary choices, and stress can all cause free radical formation and increase our need for antioxidants from our diet or supplements.
Blue and purple foods are particular rich in anthocyanins, which is what gives them their deep rich colour. Anothocyanins are powerful antioxidants that have been shown to improve brain function, and prevent cardivascular disease, cancer, diabetes and infections, by preventing blood clot formation, keeping inflammation in check and scavenging free radicals.
Add these to your weekly market haul:
Berries, Beets, Purple Cabbage, Purple Cauliflower, Purple Carrots, Purple Potatoes, Purple Grapes, Red Onions, etc...
Prepartion tips and techniques:
Antioxidants are very delicate and easily destroyed by heat and water. Red cabbage can be lacto-fermented to make saurkraut or quick pickled using sea salt and apple cider vinegar or shredded and added to a salad or slaw, much like purple carrots and beets. If you’re going to cook them, roasting, steaming and gently sauteeing, instead of boiling, perserves these delicate nutrients.
The Yellow/Orange/Red/Pink Group
This group is rich in carotenoids, yellow, orange, and red pigments synthesized by plants. The most common carotenoids are alpha carotene, beta carotene, beta cryptoxanthin, lutein, zeaxanthin, and lycopene.
Alpha Carotene, Beta Carotene and Beta Cryptoxanthin are percursors to vitamin A, which means they are converted to vitamin A in the body, which is essential for immune system function, normal growth and development of young children and preventing night blindness.
Lutein and zeaxanthin have been shown to help maintain good eye sight by filtering blue light and protecting against age related eye disease.
Lycopene is a powerful antioxidant and scavenger of free radicals.
Add these to your weekly market haul:
Sweet Corn, Green Peas, Avocado, Honeydew Melon, some leafy greens (spinach, collards, mustard greens) are rich in Lutein & Zeaxanthin
Pineapples, Oranges, Tangerines, Clementines, Peaches, Papayas, Nectarines are rich in Beta Cryptoxanthin
Carrots, Mangoes, Apricots, Cantaloupes, Pumpkin, Squash, Sweet Potatoes are rich in Alpha Carotene
Tomaotes, Red Grapefruit, Watermelon are rich in Lycopene
Preparation tips and techniques:
Carotenoids are relatively heat stable and lend themselves very well to a variety of cooking methods and in the case of tomatoes, cooking has been show to drammatically increase the bioavailability of Lycopene. Be sure to serve your carotonoid containing vegetables with a source of fat like extra virgin olive oil to optimize nutrient absorption.
The White Group
The white coloured group is known as alliums, and contain powerful organo sulfur compounds with many proven benefits
Studies have shown that allicin, a compound found in raw garlic, is an effective treatment for stomach ulcers and yeast infections due to it’s anti-microbial and anti-fungal properties and a potentially effective in the prevention of heart disease due to it’s ability to reduce the storage and production of cholesterol in the liver and it’s antioxidat properties.
While onions, leeks and shallots contain a different sulfur compound, it’s benefits are similar to that of allicin.
Add these to your weekly market haul:
Onion, Garlic, Leeks, Chives, Shallots
Preparation tips and techniques:
The bioavailability of allicin is reduced over time and with exposure to heat, so to reap the full benefits of garlic, it’s best to consume it raw within 1 hour of crushing (which releases an ezyme that activates allicin).
Other Vegetables
While I covered the major colour groups above, I didn't list all of the vegetables and it’s worth noting that there are plenty of other vegetables that you can and should include in your weekly meal plan. The list includes but is not limited to; asparagus, zucchini, green beans, snap peas, fennel, kholrabi, daikon, jerusalemme artichoke (aka sunchokes), celeriac, and so much more. The more variety you can add, the better.