What are anthocyanins and why are purple foods so healthy?
Plant compounds called anthocyanins are in headlines, and are linked to a range of health benefits. We reveal what they are, which foods contain them and why they may be a healthy addition to your diet.
We believe eating a balanced and varied diet, including at least five portions of colourful fruit and vegetables per day, is best for health. But, is there something extra-special about purple fruit and vegetables? Read on to learn more.
Why are fruit and vegetables different colours?
All brightly coloured fruit and vegetables contain colour pigments that give them their vibrant colours and act as a defence mechanism, protecting the plant from stressors like UV damage and pathogens.
What are anthocyanins?
Many purple-coloured foods contain colour pigments called anthocyanins. These plant pigments are water-soluble and have protective antioxidant properties for for the plant and us, when we include them in our diet. Anthocyanins are found in many deep red, purple and blue fruit and vegetables.
Why are anthocyanins good for us?
While research into the value of anthocyanins continues, studies to date demonstrate their benefits in the prevention of diseases associated with cell and tissue damage caused by a process called oxidation – this includes cardiovascular disease and neurodegenerative conditions. The human body absorbs anthocyanins along the gastrointestinal tract, especially in the large intestine, where they interact with the gut bugs that live there. By doing so, they help support gut health and are themselves transformed into compounds that have many health benefits, including helping prevent age-related bone loss and cancer.
Previous research has linked anthocyanins to improved longevity and a reduction in other age-related conditions such as dementia and vision loss.
Which foods contain anthocyanins?
Anthocyanins are found in high concentrations in fruits like berries, currants and grapes, as well as aubergines (in the skin of the purple varieties) and cherries. Here are some other popular anthocyanin-rich foods:
Blueberries
Studies associate a regular and moderate intake of blueberries and other anthocyanin-rich foods with a reduced risk of cardiovascular disease and type-2 diabetes, as well as improved weight maintenance. More evidence, particularly human, is needed to better understand the potential health benefits of blueberries, although it is widely agreed that including them in your diet is beneficial.
Read more about the health benefits of blueberries.
Blackberries
These berries are found in UK hedgerows from the end of the summer until October, and the anthocyanins in them can serve as a fuel source for the beneficial bugs that live in our gut. In turn, these bacteria convert anthocyanins into active chemicals that help keep our gut healthy and immune system functioning well.
Read more about the health benefits of blackberries.
Pomegranate
The jewel-like colour of the pomegranate is a consequence of its anthocyanin content. They are a good source of fibre, vitamins A, C and E and other plant compounds with protective properties, like tannins. Studies suggest that including pomegranate in your diet may help prevent various risk factors for poor health, such as high blood pressure, high cholesterol, high blood sugars and inflammation.
Read more about the health benefits of pomegranate.
Red Cabbage
Red cabbage is a nutrient-rich member of the brassica family and has been linked to a number of health benefits, including a healthier heart, improved gut function and lower risk of certain cancers. Increasing evidence supports the inclusion of red and purple fruit and vegetables in your diet, with improvements in obesity-related diseases such as type-2 diabetes.
Read more about the health benefits of red cabbage.
Purple sweet potato
Purple sweet potatoes have been in the spotlight over recent years. They are a staple on the Japanese island of Okinawa, which is home to an exceptionally healthy elderly population – a large number of which is over the age of 100. Rates of dementia on Okinawa are reported to be as much as 50 per cent lower than that in the west.
Some scientists believe this longevity may be down to the large quantities of purple sweet potato eaten by the Okinawan people. To date, however, there are only a limited number of studies examining the health benefits of the purple sweet potato, and therefore it’s impossible to say whether this is down to eating this one food specifically.
Read more about Okinawa and the diet of the Blue Zones.
Do all purple fruit and vegetables contain anthocyanins?
Anthocyanins aren’t the only pigment in fruit and vegetables that provides the deep purple-red colour; for example, beetroot contains plant chemicals called betalains, not anthocyanins. Like anthocyanins, betalains have protective antioxidant and anti-inflammatory properties. Also found in the stems of chard and rhubarb, betalains are in the flesh and skin of the beetroot.
Should I be eating more purple foods?
Although anthocyanins have many benefits, they are not considered an essential nutrient. Although a regular intake of naturally purple-coloured fruit and vegetables is an excellent addition to a varied diet, it’s also important to remember that balance is key, so aim for a rainbow of different-coloured fruit and veg.
Are dietary anthocyanins safe for everyone?
The UK, Europe, US and Canada currently has no recommended daily reference intakes or toxicity levels for anthocyanins. They are rapidly absorbed, so a regular, moderate intake of dark purple, red and blue fruits and vegetables is generally recognised as safe for most people.
Speak to your GP or healthcare provider if you are concerned about nutritional deficiencies or are considering taking supplements.
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This article was last reviewed on 14 October 2024 by Kerry Torrens.
Kerry Torrens BSc. (Hons) PgCert MBANT is a registered nutritionist with a post-graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including Good Food.
All health content on goodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.
Have you heard of anthocyanins? Which purple foods do you enjoy the most? Let us know in the comments below…