Blue and purple foods make up just 3% of the average American’s fruit
and vegetable intake
The most prominent antioxidants in blue and purple plants are a class of pigments called anthocyanins. The word anthocyanin comes from the Greek words anthos, meaning ‘flower’, and kyanos, meaning ‘dark blue’. Anthocyanins are found in many plants that span the red-purple-blue color spectrum. The shade of color is determined by the pH level of their soil environment. Anthocyanins turn bright pink in acidic soils, reddish-purple in neutral soils, and blue-green in alkaline soils. Anthocyanins help protect plants from damage caused by excess free radicals during photosynthesis. They also protect against oxidation in cell walls, and are therefore considered antioxidants as well as phytochemicals.
Red roses and blue violets also contain anthocyanins. In fact, many anthocyanins are named for the flowers that they pigment, including delphinidin (for delphiniums), petunidin (for petunias), peonidin (for peonies), rosinidin (for roses), chrysanthein (for chrysanthemums), tulipinin (for tulips), and so on.
While it is common for some fruits to contain four or five different
anthocyanins, blueberries contain no fewer than fifteen! This
unusually high concentration makes them particularly healthful, hence
their popular designation as a “superfood”. Other antioxidants found
in blue and purple plants include saponins in
eggplant, resveratrol in grapes, ellagic acid in blue and blackberries, phenolic acid in figs, and quercetin in raisins.
Studies have shown that adults who eat blue and purple fruits and
vegetables have a reduced
risk for high blood pressure and low HDL cholesterol. The phytochemical compounds and antioxidants in blue and purple foods have also been shown to protect the heart and vision, promote mental focus, inhibit the growth of cancer cells, slow age-related memory loss, and prevent urinary tract infections.