• Vicky Sham

Why Eat A Rainbow?

Updated: Jul 31

Before we launch into the topic of rainbow and all its colours, allow me a moment to check in with you. Are you consuming the right kind and amount of vegetables and fruits on a regular basis? Don't just count the greens, there are plenty of vibrant choices other than green leaves, spinach and kale. Vegetables and fruits come in all shapes, sizes, colours and specific nutrients. That's why it is important to eat a variety of vegetables and fruits to ensure we get the full range of nutrients and associated benefits for our health.


Let's take the following meals as an example, which aren't atypical. Say you have oatmeal or granola yoghurt for breakfast, beef noddles for lunch, and sushi for dinner. Maybe you'd have a snack bar or an apple or a banana muffin in mid afternoon. These aren't unreasonable meals in themselves, but I suspect you wouldn't get enough vegetables in this one day.


Now, let us explore the why and the how to eat a rainbow.


Why eat a rainbow?

Vegetables and fruits of different colours or pigments contain different phytochemicals or phytonutrients. Each colour represents different set of nutrients beneficial to our body. That’s why we need to consume all variety and colours of vegetables to ensure we get the full set of nutrients and benefits for best health.

Take a look at each colour, phytochemical/ nutrients and the different health benefits.


Red

Lycopene is a type of pigment called carotenoid, which gives tomatoes the red colour.

  • Foods: tomatoes, watermelon, pink grapefruit, red orange, apricot, guava, papaya

  • Benefits: antioxidants, may help heart health, protect against sunburns (1) and some cancers

Orange

Carotenoids (vitamin A group) account for the yellow, orange and red pigments found in plant. The carotenoids group can be converted into vitamin A and its derivative retinol important for eye health.

  • Foods: carrots, oranges, citrus fruits, bell peppers, squash, sweet potatoes

  • Benefits: antioxidants, immune system (2), eye health (3), cardiovascular, protect against cancer

Green (Leafy)

Chlorophyll is known for the green pigments from photosynthesis and are found in plants, vegetables and algae. Carotenoids are also found in green vegetables such as broccoli, kale and spinach. Both pigments are antioxidants.

  • Foods: spinach, kale, bak choy, chards, chlorella, spirulina

  • Benefits: antioxidant, heart health, protect against cancer

Green (Cruciferous)

Glucosinolates are sulfur-containing compounds found in cruciferous vegetables, such as broccoli and cabbage, which sometimes a slightly pungent and bitter taste. (5), (6), (7)

  • Foods: Brussel sprouts, cabbage, kale, broccoli

  • Benefits: anti-inflammatory, antioxidant, may support heart health and protect against cancer

Blue, Purple

Anthocyanins are water-soluble pigments called flavonoids. Anthocyanins account for red, blue and purple in plants, fruits and tubers. They appear red in acidic conditions and turn blue as pH increases and turns alkaline. Anthocyanins are found to contain antioxidative and antimicrobial properties. (8)

  • Foods: blueberries, blackberries, red or purple cabbage, grapes, eggplant, plums

  • Benefits: anti-inflammatory, antioxidant, may improve visual and neurological health (8), heart health, and protect against certain cancers

Dark Red

Betalains are water-soluble pigments, including the red-violet betacyanins and yellow-orange betaxanthins. Betanin is often used as a red food colourant, as well as cosmetics and pharmaceuticals. (9) (10). Betalain rich foods are shown to be antioxidative, anti inflammatory and may help with cardiovascular health, blood pressure and some types of cancer.

  • Foods: beetroot, rhubarb, chards, prickly pears

  • Benefits: antioxidant, blood pressure, heart health, protect against certain cancers

White/ Brown

Anthoxanthins are water soluble pigments called flavones or flavonoids, ranging from white to creamy to yellow. They are generally white when acidic and yellow in an alkaline condition. (11) Allicin is a sulfur-containing compound responsible for the smell and taste of freshly cut garlic. Allicin can inhibit the growth of bacteria, fungi, and cells, including antibiotic resistant strains of bacteria. (12)

  • Food: mushrooms, cauliflower, leeks, garlic, onions, turnips, parsnips, radish, white potatoes

  • Benefits: anti inflammatory, antioxidant, colon and other cancer, heart health

How to Eat A Rainbow

The simplest way to eat a rainbow is to aim for at least 5 colours every day, by consuming at least 3 colours per meal and at least 1 colour per snack.

A few practical ideas...

Start Counting Your Colours

Maybe by now you are already counting the different colours you have consumed in the last 24 hours. With a modern day lifestyle and abundance of convenience foods, our diet is probably too concentrated in wheat (breakfast cereal or toast), rice (obvious staples in Asia) and corn (tortilla chips for snacks). It is very easy and totally understandable that we can get through a whole day without taking in much in terms of vegetables and fruits.


Raise Your Awareness. Be Proactive

Hopefully this article will bring more awareness in what you are putting into your body so you will consciously seek out fresh vegetables and fruits on a regular basis.


Even on days that you have very little control over your food, find the opportunity to add a little colour to your food and drinks. It can be a side salad or a side of vegetables to your main dish. A fresh smoothie for breakfast or a piece of fresh fruit for snacks.


Worse come to worse, you can order a glass of water with a slice of lemon and maybe a drink with some fresh herbs. Even some herbal tea add a little something more than a can of cola.


Stock These At Home

Even if you are not a great or a frequent cook, try to make an effort to stock these items at home, not just dry foods like cereals, noodles or potato chips.


- lemons and limes, cabbages

- frozen fruits like bananas, berries

- frozen vegetables like broccoli and spinach

- pickled food like gherkins, kimchi, olives


Be creative and make "seeking out healthier options" a regular habit, in time, having 5-7 colours a day will become easier and natural to you.


By the way, I almost forgot to mention another significant benefit of colourful and fresh vegetables - dietary fibre. Dietary fibres in vegetables and fruits that are not digested nor absorbed by our body but they are hugely beneficial for our health. There are soluble and insoluble fibres. Soluble fibres dissolve in water and can help digestion, reduce blood cholesterol level, regulate blood glucose level and reduce the risk of diabetes. Insoluble fibre can help support bowel movement, reduce gut transit rate and may help reduce the risk of colon cancer. (13)


What should you do now? Start counting colours! If you achieve 7 colours a day, you will likely fulfil 5 portions of fruits & veggies too.



If you want to know more about healthy eating and healthy living, get in touch for a consultation. I can help you incorporate one little healthy habit at a time and grow towards a healthy lifestyle in a sustainable way.


#healthtips #healthcoaching #mileandbite #hkhealthcoach #eatarainbow


References

1. Ascenso, A., Pedrosa, T., Pinho, S., Pinho, F., de Oliveira, J. M., Cabral Marques, H., Oliveira, H., Simões, S., & Santos, C. (2016). The Effect of Lycopene Preexposure on UV-B-Irradiated Human Keratinocytes. Oxidative medicine and cellular longevity, 2016, 8214631. https://doi.org/10.1155/2016/8214631


2. Fiedor, J., & Burda, K. (2014). Potential Role of Carotenoids as Antioxidants in Human Health and Disease. Nutrients, 6(2), 466–488. https://doi.org/10.3390/nu6020466


3. Abdel-Aal, E.-S., Akhtar, H., Zaheer, K., & Ali, R. (2013). Dietary Sources of Lutein and Zeaxanthin Carotenoids and Their Role in Eye Health. Nutrients, 5(4), 1169–1185. https://doi.org/10.3390/nu5041169


4. Pérez-Gálvez, A., Viera, I., & Roca, M. (2020). Carotenoids and Chlorophylls as Antioxidants. Antioxidants (Basel, Switzerland), 9(6), 505. https://doi.org/10.3390/antiox9060505


5. Bosetti, C.; Filomeno, M.; Riso. P. et al. Cruciferous vegetables and cancer risk in a network of case-control studies. Ann Oncol. 2012; 23(8):2198-203. doi:10.1093/annonc/mdr604


6. Lam TK, Gallicchio L, Lindsley K, et al. Cruciferous vegetable consumption and lung cancer risk: a systematic review. Cancer Epidemiol Biomarkers Prev. 2009;18(1):184–195. doi:10.1158/1055-9965.EPI-08-0710


7. Pollack, R. The effect of green leafy and cruciferous vegetable intake on the incidence of cardiovascular disease: A meta-analysis. JRSM Cardiovasc Dis. 2016; 5:2048004016661435. doi:10.1177/2048004016661435


8. Khoo, H. E., Azlan, A., Tang, S. T., & Lim, S. M. (2017). Anthocyanidins and anthocyanins: coloured pigments as food, pharmaceutical ingredients, and the potential health benefits. Food & nutrition research, 61(1), 1361779. https://doi.org/10.1080/16546628.2017.1361779


9. Esatbeyoglu, T., Wagner, A. E., Schini-Kerth, V. B., & Rimbach, G. (2015). Betanin--a food colorant with biological activity. Molecular nutrition & food research, 59(1), 36–47. https://doi.org/10.1002/mnfr.201400484


10. Rahimi, P., Abedimanesh, S., Mesbah-Namin, S. A., & Ostadrahimi, A. (2019). Betalains, the nature-inspired pigments, in health and diseases. Critical reviews in food science and nutrition, 59(18), 2949–2978. https://doi.org/10.1080/10408398.2018.1479830


11. Anthoxanthins in Food (2015). Retrived from https://www.foodscience avenue.com/2015/07/anthoxanthins-in-food.html


12. Borlinghaus, J., Albrecht, F, Gruhlke, M.C.H., Nwachukwu, I.D., Slusarenko, A.J. (2014) Allicin: Chemistry and Biological Properties. Molecules., 19(8):12591-12618. https://doi.org/10.3390/molecules190812591


13. Holscher H. D. (2017). Dietary fiber and prebiotics and the gastrointestinal microbiota. Gut microbes, 8(2), 172–184. https://doi.org/10.1080/19490976.2017.1290756



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