Blackberries rank highly among fruits for antioxidant strength, particularly due to their dense contents of polyphenolic compounds, such as ellagic acid, tannins, ellagitannins, quercetin, gallic acid, anthocyanins and cyanidins.
Blackberries have an ORAC value (oxygen radical absorbance capacity) of 5347 per 100 grams, including them among the top-ranked ORAC fruits. Another report using a different assay for assessing antioxidant strength placed blackberry at the top of more than 1000 antioxidant foods consumed.
Raspberries contain significant amounts of polyphenol antioxidants such as anthocyanin pigments linked to potential health protection against several human diseases. The aggregate fruit structure contributes to its nutritional value, as it increases the proportion of dietary fibre, placing it among plant foods with the highest fibre contents known, up to 20% fibre per total weight. Raspberries are a rich source of vitamin C, with 30 mg per serving of 1 cup (about 50% daily value), manganese (about 60% daily value) and dietary fibre (30% daily value). Contents of B vitamins 1-3, folic acid, magnesium, copper and iron are considerable in raspberries.
Raspberries rank near the top of all fruits for antioxidant strength, particularly due to their dense contents of ellagic acid (from ellagotannins, see for instance raspberry ellagitannin), quercetin, gallic acid, anthocyanins, cyanidins, pelargonidins,catechins, kaempferol and salicylic acid. Yellow raspberries and others with pale-coloured fruits are lower in anthocyanins.
Due to their rich contents of antioxidant vitamin C and the polyphenols mentioned above, raspberries have an ORAC value (oxygen radical absorbance capacity) of about 4900 per 100 grams, including them among the top-ranked ORAC fruits.Cranberries and wild blueberries have around 9000 ORAC units and apples average 2800.
Although there are no clinical studies to date proving these effects in humans, antioxidant and antiproliferative (chemopreventive) effects against cancer have been linked to the amount of phenolics and flavonoids in various foods including raspberries.
Raspberries are a low-glycemic index food, as are most other berries.