If picked when fully ripe, blackberries are sweet and juicy; less ripe berries are tat and taste best if cooked in pies and tarts or made into jam or jelly. Wild blackberries grow on bumble bushes; picking them carries a risk of thorn scratches and stings from fruit-loving bees.
There are also several cultivated varieties: boysenberries, which are somewhat tart and dark maroon color; loganberries, which are larger than their wild cousins, dark red, and very tart; and ollalieberries, which are shiny black and sweet.
Their many seeds make blackberries high in fiber. A half-cup serving of raw berries has 40 calories and supplies 15mg of vitamin C, or 25% of Recommended Daily Allowance (RDA), as well as 10mcg (micrograms) of folate, 2.5mg of vitamin E, and small amounts of iron and calcium.
Blackberries contain ellagic acid, a substance that is believed to help prevent cancer. Cooking does not appear to destroy ellagic acid, so even jams may confer this health benefit.
People who are allergic to aspirin may find that they experience a similar reaction from eating blackberries. The reason for this is that blackberries are a natural source of salicylate, an ingredient found in aspirin.
Blackberries are low in calories and high in fiber. They are a good source of vitamin C and bioflavonoids; they also contain folate, vitamin E, iron and calcium. Blackberries contain anticancer chemicals, such as chlorogenic acid, ellagic acid and anthocyanins.