Phytonutrients: Fill Your Plate with Rainbow Colors of Fruits and Vegetable

The rainbow diet is a health-inspired trend that wants you to eat colourful fruits and vegetables. Fruits and vegetables fall into five different colours category: Red, Yellow/Orange, White, Purple/Blue and Green. Each category of them provides us a set of unique phytonutrients. This is why a balance of all colors is most important.  

What are Phytochemicals?

Phytochemicals are the unique compound that give fruit and vegetables their rich colours, as well as their distinctive tastes and aromas. The function of phytonutrients is to strengthen a plant's immune system. They protect the plants from extreme environmental conditions, such as excessive sun exposure, free radicals damage, and resist fungi, bacteria and viral infections. When we eat plants food, these phytochemicals do offering us some health benefits to prevent certain chronic diseases. 

What are the Health Benefits of Phytochemicals? 


Food in red colour are rich in lycopene. Lycopene is a powerful antioxidant. This powerful phytonutrient does show some protective effect against prostate cancer, as well as heart and lung disease. In order to get this powerful free radicals scavenger lycopene from your diet, eat more red colour food like strawberry, tomato, red bell pepper, chilis, apples, cranberry, red beet and watermelon. In addition, lycopene has been shown to protect skin against sun exposure to slow down skin aging. Heat processing increases the bioavailability of lycopene. If you want to enjoy the full benefits of lycopene, try to bake your tomatoes, stir fry your red bell pepper or make your tomato soup instead of eating them raw. Since lycopene is a fat-soluble compound, you may eat these foods together with some fats like butter or olive oil, it helps to increase the absorption of lycopene. 


Carotenoids give these food their vibrant colour. Yellow and orange colored food are rich in beta-carotene. Beta-carotene is a pro-vitamin A which in turns converted into Vitamin A in our body. Beta-carotene is important for our immune system, maintain healthy skin and mucus membrane, and for our eye health and good vision. Food rich in beta-carotene are carrot, pumpkin, squash, mango, papaya and orange. Beta-carotene is much more safer than Vitamin A because excessive Vitamin A intake can cause toxicity to our body. However, beta-carotene will only be converted into Vitamin A when our body needs it. The other important carotenoids are lutein and zeaxanthin which is important for your eye health as it helps to prevent or slow down cataract and age-related macular degeneration. Just like lycopene, cooking does increase the concentration of beta-carotene, so cook your carrot or pumpkin with some healthy oil rather than consuming them in raw. 


Cruciferous vegetables contain cancer-fighting phytochemicals glucosinolates, sulforaphane and indoles. These compounds give cruciferous vegetables their sharp odor and flavor. Enjoy a variety of cruciferous vegetables like broccoli, cauliflower, kale, Brussel sprout, watercress and spinach in your diet. This sulfur containing phytochemical glucosinolates will be broken down by our gut into isothiocynate, for example sulforaphane. Glucosinolates exert antioxidant, anti-inflammatory and anti-cancer properties. Besides, glucosinolates increase the production of our body master antioxidant- glutathione. They involve in liver detoxification which helps to neutralize and eliminate harmful toxins from our body. Study shows that eating 4-5 servings of cruciferous vegetables per month decreases risk of lung cancer by 55%. Another study shows that women who ate a greater amount of cruciferous vegetables had a lower risk of breast cancer. 


The onion family contains allicin, the phytochemical that gives onion its distinctive odor. The onion family which includes chives, garlic, onion, leek and shallots. Allicin is important for our heart health, where it helps to reduce high blood pressure and cholesterol level. Several studies shows that allicin and other garlic compounds may have protective effect for some cancers. Beside that, onion also contains other phytochemicals like kaempferol and quercetin, which exert powerful antioxidant properties. 


Blue and purple fruits and vegetables contain phytochemicals called anthocyanins. Anthocyanins has antioxidant properties that protect cells from free radicals damage and can help to reduce risk of cancer, stroke and heart disease. Anthocyanins can be found in blueberry, blackberry, purple sweet potato, purple cabbage and eggplant. Resveratrol is another phytochemicals found in grapes, purple grape juice and red wine. Studies show that resveratrol activates SIRT-1 gene which promotes longevity. Activation of this longevity genes slows down aging and the onset of age-related diseases. This could be due to SIRT-1 gene confers antioxidant activity and suppress inflammation. Besides, activation of SIRT-1 by resveratrol promotes mitochondrial biogenesis, which means it increases the number of mitochondrial and improves mitochondrial function. 

In conclusion, we are recommended to consume 4-5 servings of fruits and vegetables everyday. The more the variety we consume, the better the health benefits we will get.