What are anthocyanins? It is a plant compound that acts as an effective antioxidant within the human body. These are beneficial plant pigments that gives many fruits and berries a blue, red or dark purple colouring and is found in a wide assortment of healthy foods.
So do we need to eat lots of these foods? While studies are ongoing, it’s too early to say conclusively whether anthocyanins deserve the recent media headlines that label purple foods as ‘superfoods’. But previous research has linked anthocyanins to a wide variety of health claims, including increased longevity, cardiovascular health, cancer prevention and dementia so hopefully you will benefit health wise from a diet including these purple foods.
Anthocyanins are found in high concentrations in blackcurrants, blackberries and blueberries, as well as in aubergine (in the skin), red cabbage, cranberries and cherries.
Purple sweet potatoes are commonly eaten on the Japanese island of Okinawa, which is home to an exceptionally healthy elderly population – with a large number over the age of 100, and rates of dementia reported to be up to 50% lower than in the West. Although some scientists think that the large quantities of purple sweet potato in their diet plays a key role in keeping their bodies and brains healthy well into old age, it is impossible to say that the Okinawan’s longevity is down to this one food alone as there have not been enough studies researching the health benefits of these potatoes.
Beetroot’s deep purple colour comes from plant chemicals called betalains which like anthocyanins, have antioxidant and anti-inflammatory properties. These betalains can also be found in the stems of chard and rhubarb but it’s the flesh and skin of beetroots which are especially rich in them. Beetroot is also a good source of vitamins and minerals, including folate, iron, manganese and potassium. One study has found that consuming beetroot juice was linked with lower blood pressure. Another study suggested that a diet that includes beetroot juice may increase blood flow to the brain, which some have interpreted to mean it may help prevent or improve dementia.
Blueberries which have a high anthocynanin content are also high in vitamin C, which helps protect cells and aids the absorption of iron, and contain soluble fibre, which is beneficial to the digestive system. A study in the European Journal of Nutrition found that a supplement containing dried blueberry powder improved brain power in children aged 7 to 10. Research has also suggested that consuming a blueberry supplement may be effective in improving or delaying short-term memory loss in rats. However as the existing studies into how blueberries might prevent cancer or improve memory have so far relied on small sample groups or animals, and it is not yet clear whether these findings will translate to larger groups of the human population.
Pomegranate is a good source of fibre, and also provides vitamins A, C and E, iron, and other antioxidants such as tannins.
There is evidence to suggest that the antioxidants in pomegranates also benefit your heart in a number of ways, including lowering systolic blood pressure, slowing, and even reversing, the growth of plaque formation in arteries.
The antioxidants in pomegranates may also help to reduce inflammation that contributes to the destruction of cartilage in your joints, a key reason for the pain and stiffness felt by many osteoarthritis sufferers. One study found that pomegranate helped to strengthen bones and prevent osteoporosis in mice through decreased inflammation and oxidative stress.
Just a spoonful of black rice bran contains more health promoting anthocyanin antioxidants than are found in a spoonful of blueberries, but with less sugar and more fibre and vitamin E which has been known to fight ageing and combat heart issues.
There’s no doubt that naturally purple-coloured fruit and vegetables are an excellent addition to a varied diet, but it’s also important to remember that balance is key and include a rainbow of different colours of fruits and vegetables for optimum health benefits.