If you are one of those people who always chooses the same fruits and vegetables, try to challenge yourself to discover new tastes. To get the maximum amount of vitamins, minerals and bioactive nutrients follow the simple principle: try to eat fruits and vegetables of all the colours of the rainbow every day: red, orange, yellow, green, blue, purple, and instead of light blue – white. And why is that a good idea?
The colour of plants indicates the presence of certain nutrients. Some of those nutrients and their health benefits are described below. Different coloured pigments have different potential health benefits, that’s why diversity on your plate is good.
Tomatoes, watermelons, pink grapefruits
Red fruits and vegetables are naturally coloured by the carotenoid lycopene. Among all the carotenoids, lycopene predominates in human plasma and various tissues and prostate. It is believed that regular consumption of lycopene may significantly reduce the risk of prostate cancer. The main sources of lycopene are tomatoes and its sub-products (tomato paste, tomato sauce), watermelons, pink grapefruits, guavas and papayas.
Lycopene is also an effective oxygen quencher, i.e. it combats oxidative stress.
By the way, lycopene is lipophilic (“loves fat”). This means that its optimal uptake occurs in the presence of dietary fats. A practical example: a tomato sauce cooked with a little oil is a much better source of lycopene than raw tomatoes.
Carrots, pumpkins, apricots
The carotenoid beta-carotene is found in orange and yellow fruits and vegetables: carrots, pumpkins, yellow apples, apricots, peaches, orange melons. Beta-carotene is converted in the human body into vitamin A, which helps maintain the health of the mucous membranes, skin and eyes.
Bell-peppers, corn, grapes
Zeaxanthin is one of the most common carotenoids found in nature. This pigment is synthesized in plants and it gives them their characteristic orange and yellow colour. The name comes from Zea Mays (common corn variety) and Xanthos, the Greek word for “yellow.”
Zeaxanthin is the main component of the pigment in the retina. A small amount of zeaxanthin is also found in our brains. Zeaxanthin plays an important role in the functioning of the eye, as it is responsible for central vision sharpness (clarity with which objects are distinguished from their environment).
Important food sources of zeaxanthin are corn, yellow and orange bell-peppers, dry paprika, saffron, all varieties of pumpkin and squash, kiwis, grapes, orange juice and goji berries.
Green: Vitamin K
Parsley, cabbage, spinach
Vitamin K is found mainly in foods of green colour: greens, cabbage, lettuce. Only 10 grams of fresh parsley will provide you with double the RDA of this vitamin. Another excellent source of vitamin K are cruciferous vegetables such as cauliflower, cabbage, garden cress, bok choy, broccoli, Brussels sprouts. Plenty of vitamin K is also found in spinach and arugula. Vitamin K is important for the formation of blood clots and is essential for optimal bone health.
Blue and purple: anthocyanins
Blueberries, eggplants, açaí
Anthocyanins are blue, dark-red or purple pigments in berries, fruits, vegetables and leaves. Scientists believe that anthocyanins can slow cognitive (mental) aging.
Not so long ago in the journal Annals of Neurology results were published of a study which analysed the data of more than 16 thousand elderly women. The researchers concluded that women who regularly (at least twice a week) ate berries, mainly blueberries and raspberries, cognitively aged two and a half years later than women who ate berries irregularly.
How does this happen? The most common theory is that berries’ flavonoids anthocyanins can pass the blood-brain barrier and localize in the in areas of the brain responsible for learning and memory processes (for example, in the hippocampus).
Anthocyanins are found in strawberries, raspberries, blueberries, exotic açaí berries and eggplants.
White: allicin and potassium
Onions, potatoes, bananas
White fruits and vegetables are coloured by the pigment anthoxanthin. Onions and garlic contain a chemical substance, allicin, that promotes health. It can lower cholesterol and blood pressure, as well as potentially reduce the risk of stomach cancer and heart disease.
Some representatives of the white group, such as bananas and potatoes, are good sources of the mineral potassium. Potassium is responsible for water balance within the cells.
The bioactive nutrients described above are not the only healthy elements in fruits and vegetables of different colours. Thousands of other known and unknown substances are found in different varieties of vegetables and fruit, and they all have certain health benefits. The key to healthy eating, therefore, is diversity.
FYI: the World Health Organization recommends eating a minimum of 400 grams of fruit and vegetables every day.