Eating the rainbow: an in-depth guide
You may have heard that it’s important to add colour to your plate – but why is this?
If you’ve ever heard the term “eat a rainbow” before, it refers to incorporating fruits and vegetables with a variety of different colours into your daily eating plan. Plant-based foods contain different pigments known as phytonutrients, which are also sometimes referred to as phytochemicals. These are natural compounds found in plants, including fruits, vegetables, whole grains, nuts, legumes, and seeds. Phytonutrients impart deep, rich colours to fruits and vegetables, and contribute to their taste and aroma. Think of vibrantly coloured berries, the bitterness of Brussels sprouts or fragrant garlic – phytonutrients are responsible for each of these characteristics.
Many phytonutrients have antioxidant properties that protect against free radicals; natural compounds that can damage the cells in your body and contribute to the process of aging. The different colours of fruits and vegetables are linked to the presence of specific phytonutrients, each with different health benefits. Overall, many studies suggest that a diet rich in fruits and vegetables can support overall health with protective effects for the heart, eyes, brain and digestive system, and help with weight management efforts.
Let’s explore the different colours in foods and what those colours mean from a nutritional standpoint:
Red and pink-hued fruits and vegetables are rich in carotenoids (including lycopene), flavones, and anythocyanins. They are also good sources of vitamin C.
Nutritional benefits: Provides antioxidant, anti-inflammatory, and immune health benefits. For example, lycopene (rich in tomatoes) has been shown to support heart health and may offer protective effects for prostate and breast health.
Food examples: Tomatoes and tomato products (including cooked tomato sauce), red bell peppers, red onions, beets, cherries, pink grapefruit, watermelon, strawberries.
Orange and Yellow
Bright orange and yellow produce are rich in carotenoids (including beta-carotene, which is converted in the body into vitamin A) and lutein. They are also good sources of vitamin C.
Food examples: Carrots, orange and yellow peppers, squash, sweet potatoes, apricots, oranges, lemons, cantaloupe, mangoes, pineapple.
A natural pigment called chlorophyll is what brings the deep green colour to many vegetables. Compounds found in this colourful group of produce may include indoles, isothiocyanates, (including sulforaphane), and carotenoids. Green vegetables are also good sources of many vitamins and minerals.
Nutritional benefits: Dark, leafy greens are important for heart health due to their presence of vitamin K, magnesium, potassium, and folate. Cruciferous vegetables, such as broccoli and cabbage, offer both antioxidant and anti-inflammatory properties. In particular, they are rich in sulforaphane, which has been shown to offer protective effects throughout the body.
Food examples: Broccoli, cabbage, kale, spinach, Brussels sprouts, green beans, green peppers, asparagus, zucchini, limes, pears, avocadoes, kiwi.
Blue and Purple
Richly-coloured blue and purple fruits and vegetables are good sources of compounds that include anthocyanins, flavonoids, and flavanols.
Nutritional benefits: Provides antioxidant properties that are beneficial for heart health and healthy aging, including memory and cognition. There is research to show that blueberries in particular, offer wide-ranging health benefits due to their high content of antioxidant compounds, and rich source of fibre, vitamins A and C, potassium, and folate.
Food examples: Blueberries, blackberries, plums, purple grapes, prunes, eggplant, purple cabbage.
Here are some tips to help add more colour to your plate:
Prioritize variety. Choose a variety of fruits and vegetables every day. No single fruit or vegetable is a “superfood” that can provide you with all the nutrients you need. The mix of antioxidants and nutrients you get from a variety of foods is best for overall health.
Convenience is key. Buying pre-washed, pre-cut fresh or frozen produce can save you a lot of preparation time in the kitchen. You can easily toss baby carrots, leafy greens or frozen mixed vegetables into soups, salads, pastas and casseroles.
Try new things. Make it fun to incorporate new vegetables and fruits into your eating plan by experimenting with new recipes. Even different cooking methods such as roasting, grilling or stir frying can completely change the taste and texture of a vegetable that you may not have previously enjoyed.
Think with an addition mindset. Boost the nutrition of dishes you’re already preparing by adding sliced or chopped produce. For example, you can easily add tomatoes, peppers and onions to salads, sandwiches and pastas. Blend a mix of chopped fruit into a delicious smoothie or top yogurt, oatmeal or whole grain cereal with fresh or frozen berries.