From Green to Purple: Phytonutrients that give fruits and vegetables their colours and health benefits

By Sandra A. Farrell, MSc, BA, Contributor

Colour your plate with nature’s goodness! Phytonutrients – natural compounds in fruits and vegetables, may help to reduce the risk of chronic diseases. Their colours tell a vibrant story: green leafy vegetables glow with carotenoids and chlorophyll, while deep purple berries are packed with anthocyanins, a type of apolyphenol. Eating a rainbow of colourful fruits and vegetables is a simple way to boost your intake of essential nutrients and phytonutrients.

Exploring phytonutrient rich foods

Green foods rich in lutein and chlorophyll (broccoli, spinach) and support eye and liver health. Blue, purple and black foods contain anthocyanins and other compounds (blueberries, eggplant) for brain and heart health. Red foods, high in lycopene (tomatoes, red peppers) aid heart and prostate health. Orange foods provide beta carotene (carrots, sweet potatoes) for vision. Yellow foods contain lutein (pineapple, corn) supporting immunity. White/tan/brown foods are rich in selenium and cellulose (mushrooms, ginger) and provide digestive and heart health benefits.

Blueberries & anthocyanins: Unlocking the colour of purple

Professor Ana Rodriguez - Mateos, an expert in human nutrition at King’s College London (KCL) who has studied blueberries for over 2 decades, suggested that they are full of polyphenol flavonoids called anthocyanins – a purple pigment that gives berries their deep colour.

Blueberries are good sources of fibre and polyphenols that nourish beneficial gut bacteria and support microbial diversity. Professor Rodriguez - Mateos further highlighted that research shows that berries have a probiotic effect on the gut and improves the diversity in our gut microbiome.

A further study found that consuming wild blueberries was linked to improvements in memory performance and lowering of blood pressure.

Is it necessary to peel fruits and vegetables?

I tend to avoid peeling most fruits and vegetables as they contain fibre and a rich source of phytochemicals particularly polyphenols. To wash, under running water, rub fruits and vegetables briskly. Firm skinned produce can be scrubbed gently with a vegetable brush.

Professor Tim Spector, a prominent UK based genetic epidemiologist at King’s College London and expert in personalised nutrition and gut microbiome, suggest that you could be losing some of the vital nutrients from your food through peeling. He further noted that the skin of fruits such as apples, kiwis and vegetables contain polyphenols.

Interestingly, the peel of citrus fruits contain a larger amount of polyphenols compared to the edible portion of the fruit, making it nutritionally valuable. The peel of citrus fruits can be used to add zest and flavour to dishes, infuse teas, enhance baking, blend into smoothies, create spice blends and prepare citrus infused oils and vinegars.

Frequently Asked Questions

• What are phytonutrients and why are they important in our diet?

Phytonutrients are thousands of different healthful compounds in plants. Eating a variety of phytonutrient dense fruits and vegetables provide health benefits. In research conducted, people who eat more plant foods tend to have lower rates of heart disease, cancer, diabetes, dementia and other chronic diseases.

• How can I increase my intake of phytonutrients?

Observe your meals and colours eaten on a daily basis. Whenever possible, gradually shift to eating a broader spectrum and colour diversity. ‘Eat the Rainbow’ a concept which includes eating a variety of colourful fruits and vegetables in your diet.

• Are some plant foods richer in phytonutrients than others?

The answer is yes. Some plant foods have more phytonutrients than others. For example sweet potatoes or purple potatoes contain more phytonutrients than white potatoes. One approach is to swap foods that are lower in nutrients for more nutrient dense alternatives.

• Should we aim to eat a variety of phytonutrients?

In nature, there are thousands of phytonutrients. Instead of getting blue purple phytonutrients from blueberries, try other blue purple foods like purple rice and purple cabbage which will give different phytonutrients. One helpful tip is to try a new food every week to ensure a variety of phytonutrients.

About the Author

Sandra A. Farrell is a UK based Registered Nutritionist and member of Plant Based Health Professionals (UK). She has a MSc in Global Public Health Nutrition, BA (Hons) in Food, Nutrition and Professional Cookery and additional qualifications in Psychology, Health and Wellbeing Coaching, Health Behaviour Change, Health Improvement, Plant Based Nutrition, Setting up and Hosting Healthy Eating Cookery Clubs, Education and Training, Horticulture and Garden Design. Sandra is presently pursing further studies in Behavioural Science to promote health and wellbeing. She is a mentor with Trailblaze St Kitts and Nevis, a mentorship initiative empowering youths in St Kitts and Nevis, by connecting with professionals for guidance, skill development and career preparation.

Disclaimer

The contents of this article, regardless of date, is not intended to replace personalised medical advice from your doctor or healthcare professional.