Can eating a rainbow coloured diet help to improve your eyesight, Rob Hobson explains

The idea of colour coding your health has been around for some time now and the phrase, ‘eat the rainbow’ has been widely used to illustrate the importance of eating different coloured foods.  The most important of these colours are the reds, oranges and greens that can help you to ‘traffic light’ your way to good health.  This is not to say you shouldn’t eat any other coloured foods but adding an extra serving of each of these traffic light colours daily is a good habit to get into.

Using the traffic light diet will help support your eye health but will also ensure you glean key health-giving phytonutrients that help to pave the way to future-proofing your health for years to come.

Reds and Pinks

Lycopene is one of the most potent carotenoids and can be found in high concentration in tomatoes and in particular processed varieties such as canned, pureed or sun-dried.  You can also find lycopene in watermelon, red grapefruit, pomegranate and strawberries.   Most of the studies on lycopene have been centred around tomatoes, and have shown that this phytonutrient may have a protective effect against the risk of stroke by way of its antioxidant capacity, as well as reducing inflammation in the body and lowering total and LDL cholesterol.  There is also research to suggest a potential benefit to protecting against certain cancers such as breast and prostate (although the latter is thought to be less than previously thought).

Anthocyanins are from a group of phytonutrients called flavonoids and these pigments give fruits and vegetables their vivid red and blue colours.  Foods with the highest concentration of anthocyanins are berries, red and purple grapes, cherries and strawberries.  There are many studies that have shown a protective effect of anthocyanins against cardiovascular disease.  One very large study of 93,600 healthy women followed over 18 years, showed that those with a high intake of anthocyanins had a reduced risk of heart disease and those eating more than three servings of berries weekly had a 34% lower risk compared with those who did not.  Ellagic acid is found in high amounts in strawberries and pomegranates and studies have suggested that this phytonutrient may have a protective effect against certain cancers by inhibiting mutations with the cell’s DNA.

Phytonutrients of red and pink foods

Lycopene, ellagic acid, anthocyanins, beta-carotene, betanin, capsaicin 

Which red and pink foods to eat

Raspberries, tomatoes, red onions, radish, strawberries, cranberries, red cherries, red grapes, pomegranates, pink grapefruit, watermelon, guava, red peppers, beetroot, red chillies and red apples

How to increase red foods in your diet

Add a glass of tomato, pomegranate or beetroot juice to your diet
Make use of red berries to create a tasty smoothie
Try fresh tomato gazpacho as a tasty snack
Use red berries as yoghurt or porridge topping
Try radicchio with blue cheese and walnut for a tasty salad
Make a batch of tomato, red pepper and chilli sauce (great base for pasta, pulses or meats)
Roast beetroot with cumin seeds
Make a tasty side dish of sliced tomatoes, red onions, olive oil and basil

Yellow and Orange

Beta-cryptoxanthin, beta-carotene and alpha-carotene are all present in orange foods and belong to the carotenoid family.  These are converted to vitamin A in the body, which is essential for good eye health and immunity as well as healthy skin and bones.  Beta-carotenes have also been associated with protecting against certain cancers, specifically those of the lung, oesophagus and stomach.

Studies show beta-carotene may also have a protective effect against heart disease and early research has also suggested a link between low levels of beta-carotene (and vitamin C) and early onset dementia, although more research is required.

Yellow foods are a good source of lutein, which is especially beneficial for eye health as together with other potent antioxidants, this phytonutrient helps to block out visible blue light, which is one of the major causes of light induced eye damage.  Rich source of lutein are found in egg yolks and sweetcorn as well as other green foods (see below). 

Although diet should always come first, supplements are available.  We know foods rich in vitamins C and E, zinc, lutein, zeaxanthin, and omega 3 fatty acids DHA and EPA are good for eye health and these nutrients are linked to lower risk for age-related macular degeneration (AMD), cataract and dry eye later in life. It’s worth supporting our diet with a supplement such as Healthspan’s new Retinex® Max which contains 20mg of natural lutein and 2,000?g of zeaxanthin sourced from marigolds. Vitamin B2 (riboflavin) which is also included can play a role in maintaining healthy levels of these nutrients in the eyes.

Research has also suggested that lutein may support brain function and memory.  Some people with mild cognitive impairment have been shown to have a reduce lutein status and studies that have increased the intake of this phytonutrients have shown significant improvements using verbal recall scores.

Phytonutrients of yellow and orange foods

Lutein, bioflavonoids, alpha-carotene, beta-carotene, beta-cyrptoxanthin and limonene

Which yellow and orange foods to eat

Butternut squash, mangoes, galia melons, peaches, nectarines, dried apricots, satsuma, yellow peppers, orange peppers, passion fruit, carrots, swede, grapefruit, sweetcorn, pineapple

How to increase yellow and orange foods in your diet

Try adding sweetcorn or dried fruits such as apricots to salad or rice dishes
Try roasting squash and carrots with cumin seeds
Include grapefruit as part of your breakfast
Grill halved peaches and serve with raspberry coulis and hazelnuts
Mash swede and carrots with a little nutmeg
Serve pineapple after meals (pineapple also contains papain that helps to digest protein in food)
Stuff peppers with rice, dried fruit, feta and Moroccan spices then bake
Snack on slices of mango drenched in lime juice

Greens

Cruciferous green vegetables including broccoli and kale contain indoles that studies show may help to protect against breast cancer and also another compound called sulpheraphane that may help to lower the risk of colon cancer.

Green vegetables are a great food for the eyes.  Lutein and zeaxanthin are found in high concentration in the macula, which is an area within the retina of the eye.  One purpose of these phytonutrients is to help filter out harmful light that can potentially damage the eye.  Large studies have shown that these nutrients help to lower the risk and slow down the development of age-related macular degeneration (AMD), which is a leading cause of blindness in older people.  Further studies have also shown that people with the greatest intakes of foods rich in lutein, zeaxanthin and beta carotene, in particular kale, spinach and broccoli, are less likely to develop cataracts.

Luteolin is also found in green foods, in particular green peppers and celery and has been shown to lower inflammation in the brain and central nervous system.  Like white foods such as onions and garlic, green fruits and vegetables such as chillies also contain quercetin, which has an anti-inflammatory effect in the body.

Like orange fruits and vegetables, greens are also a rich source of beta-carotene.  This antioxidant has been shown to help reduce inflammation and is particularly important for healthy skin and heart.

Phytonutrients of green foods

Lutein, beta carotene, zeaxanthin, luteolin, quercetin and indoles

Which green foods to eat

Avocado, spring greens, rocket, spinach, watercress, cucumber, Brussels sprouts, kale, spring onions, green peppers, grapes, kiwi fruit, peas, sugar snap peas, leafy cabbage, courgette, pak choi, lettuce

How to increase green foods in your diet

Snack on sliced mange tout or sugar snap peas
Add rocket, spinach or pak choi to salads
Throw a handful of peas into salads, pasta dishes, curries or stews
Make homemade guacamole using avocado, red onions, tomatoes, lime juice, coriander
Grate courgette into an omelette
Stir-fry sliced spring greens with soy, ginger and garlic
Use lettuce leaves in place of tortilla wraps for a lower calorie Mexican food option
Bake kale pieces in a low over then sprinkle with sea salt and smoked paprika

Make Rob Hobson’s Mexican Prawn and Black Bean Salad perfect for good eye health

Healthspan Retinex Max: Suitable for Vegans and Vegetarians 60 tablets £19.95

Rob Hobson is Healthspan Head of Nutrition and author of The Detox Kitchen Bible, published by Bloomsbury.