Anthocyanins are the active component in several herbal folk medicines such as bilberry (Vaccinium myrtillus), which was used in the 12th century to induce menstruation and during World War II to improve British pilots' night vision. Scientists are now discovering how such anthocyanins work and are beginning to appreciate their health benefits.
There are 6 commonly occurring anthocyanidin structures. However, anthocyanidins are rarely found in plants - rather they are almost always found as the more stable glycosylated derivatives, referred to as anthocyanins.
Anthocyanins are naturally occurring compounds that impart color to fruit, vegetables, and plants. Derived from two Greek words meaning plant and blue, anthocyanins are the pigments that make blueberries blue, raspberries red, and are thought to play a major role in the high antioxidant activity levels observed in red and blue fruits and vegetables.
Anthocyanins link with sugar molecules to form anthocyanins; besides chlorophyll, anthocyanins are probably the most important group of visible plant pigments. Anthocyanins, a flavonoid category, were found in one study to have the strongest antioxidizing power of 150 flavonoids.
Widely distributed among flowers, fruits, and vegetables, anthocyanins belong to a group of plant compounds called flavonoids. Flavonoids are a subclass of plant polyphenols that may have antioxidant abilities and are being studied for their anticancer potential. Currently under investigation for their ability to inhibit LDL (the "bad") cholesterol, prevent blood clotting, and defend cells against dangerous carcinogens, anthocyanins may prove to be significant compounds in human health.
Studies show anthocyanins' positive influences on a variety of health conditions. One reason is their anti-inflammatory properties, which affect collagen and the nervous system. Their ability to protect both large and small blood vessels from oxidative damage derives from a range of effects, including mitigating microvessel damage from high blood-sugar levels that cause complications in diabetics. By the same token, diabetic retinopathy, which damages eyesight, is caused by leaking, damaged capillaries.
The available evidence indicates that staying close to the source used in the mice experiments, blueberries, is best. Other sources should be considered if blueberries are not available.