More colourful meals are healthier

Most people know it’s healthy to eat at least five servings of fruits and vegetables a day. This is because they are whole foods, created by nature, that are rich in nutrients.

But sticking to the ‘five rule’ is not really enough. To get all the essential vitamins and minerals your body needs, you should also eat fruits and veg that offer plenty of colour variety.

As researchers probe the once-hidden depths of foods, they're discovering that vitamins and minerals are merely the tip of the nutritional iceberg. For example, Albert Szent-Gyorgyi, Ph.D., the Nobel laureate who discovered vitamin C, first isolated flavonoids in the 1930s. He then went on to find that they strengthened capillary walls in ways vitamin C could not. Researchers have subsequently identified more than 4000 flavonoids in plants.

Flavonoids create a dazzling display of colours in fruit and vegetables. But other nutrients also give us visual clues when they are present.

Here are some examples:

Red

Nutrients such as lycopene, ellagic acid, quercetin and hesperidin help to lower blood pressure, reduce the risk of prostate cancer, reduce tumour growth and cholesterol levels, scavenge harmful free-radicals, and support joint tissue in arthritis sufferers.

Clinical studies have proven that lycopene, found in tomatoes, decreases the risk of prostate cancer and protects against heart disease.

Quercetin, found in red apples, red onions and other citrus fruits, contains anti-histamines and is anti-inflammatory. This nutrient not only prevents LDL cholesterol oxidation, but also helps the body cope with allergens and lung and breathing problems.

Ellagic acid, from raspberries, strawberries, pomegranates, and walnuts, has been proven to act as an antioxidant and anti carcinogen in the gastrointestinal tract. It also slows the growth of cancer cells, because it decreases their ATP production.

Hesperidin has antioxidant and anti-inflammatory properties and is used to treat hypertension and haemorrhoids

Orange / Yellow

Beta carotene, xeaxanthin, flavonoids, lycopene, potassium, and vitamin C help reduce age-related macular degeneration (eye condition found in mature adults) and the risk of prostate cancer. They also lower LDL cholesterol and blood pressure, promote collagen formation and healthy joints, fight harmful free radicals, encourage alkaline balance, and work with magnesium and calcium to build healthy bones.

Flavonoids are plant pigments and potent anti-oxidants that help to stop the growth of tumour cells. They can also reduce inflammation.

Vitamin C keeps our immune system strong, speeds up the healing of wounds and promotes strong muscles and joints. Although found in many fruits, it is most commonly associated with oranges and other citrus fruits.

Bioflavonoids, found in citrus fruits, are considered a companion to vitamin C because they extend the value of it in the body and help to lower cholesterol levels and support joint collagen in arthritis cases.

Beta carotene is converted into vitamin A upon entering the liver. Known for its positive effects on eyesight, it has also been proven to reduce cholesterol in the liver.

Potassium helps heart functioning and lowers blood pressure.

Green

Green vegetables contain chlorophyll, fibre, lutein, xeaxanthin, calcium, folate, vitamin C, calcium, and beta carotene. These reduce cancer risks, lower blood pressure and cholesterol levels, aid digestion, improve vision, fight harmful free-radicals, and boost immune system activity.

Research suggests that only around 20% of us are getting enough calcium. Also, surprisingly that if you don't get enough calcium in your diet, you're likely to be overweight. (Of course, it's possible to be overweight even if you do get plenty of calcium.) Calcium affects heart health and pre-menstrual moods positively.

Blue / Purple

These contain nutrients such as lutein, xeaxanthin, resveretrol, vitamin C, fibre, flavonoids, ellagic acid, and quercetin. Collectively they help to support retinal health, lower cholesterol, boost our immune systems, aid digestion, improve mineral absorption, fight inflammation, reduce tumour growth, act as anti-carcinogens in the digestive tract and limit the activity of cancer cells.

Lutein, which is found in blueberries and members of the squash family, is especially important for healthy eyes but can also help prevent against coronary artery disease.

White

These contain nutrients such as beta glucens, EGCG, SDG, and lignin that provide powerful immune boosting activity. They also activate natural killer B and T cells, reduce the risk of colon, breast and prostate cancers, and balance hormone levels which reduces the risk of hormone-related cancers.

Beta glucens found in mushrooms, help to balances the body's immune system by supporting white blood cells. They also have a positive effect on heart disease patients.

Lignin may help with the treatment of gallstones, high cholesterol and colon cancer.

On a slightly different note, EGCG, found in tea along with flavonoids, has been shown to reduce the risk of colon and breast cancer. It also boosts the immune system and encourages T-cell formation. This defends our body against sickness and disease.

Do bear in mind that because frozen fruits and vegetables retain much of their original nutritional value they can be a good alternative when certain foods are out of season. As are fruit and vegetable drinks.

Ultimately, with the rise in cases of type 2 diabetes, heart disease, high cholesterol and hypertension that result from the "typical western diet” ( rich in meats, processed sugars and refined grains) it is clear that universally we need to eat more fruits and vegetables. Also that we need colour in our diet.

Table: Fruit and vegetables classified according to colour