Last updated by Dr Sarah Brewer on
Acai (pronounced a-Sah-ee) berries are the fruit of a Brazillian palm, Euterpe oleracea, that is also a source of ‘hearts of palm’ – the soft, inner shoot tips that are popular in salads.
Acai berries are small and round with a similar size and appearance to grapes, but with an oily coating, less pulp and a single, large seed. As the berries ripen they turn from green to a dark, purple-black and taste similar to wild raspberries with a hint of grape. Bunches of ripe fruit can weight up to 5kg or more.
As a food, acai berries are used to make smoothies, juices, ice-cream and are also added to breakfast cereals. Outside of South America, acai berries are mainly available as powder or tablet supplements prepared by flash freezing.
Health benefits of acai berries
The level of antioxidants found in fresh acai juice is below that of pomegranate, blueberry and black grape juice, similar to that of cranberry and black cherry juice, but greater than orange juice, apple juice and iced tea.
Freeze-dried acai pulp/skin powder is a rich source of anthocyanin polyphenols and has one of the highest antioxidant levels of any food tested at 161,400 ORAC units (microTE/100g) which is even higher than for dark chocolate (103,971 ORAC units), and higher than for Goji berries (25,300 ORAC units). Eating acai pulp has been shown to double or even triple the antioxidant capacity of blood plasma.
Acai berries are also a good source of fibre, omega-3 essential fatty acids and oleic acid – the same monounsaturated fat as that found in olive oil – and provide useful amounts of calcium, iron, manganese, plant sterols (mainly betasitosterol), and lignans (a type of phytoestrogen).
Acai can reduce inflammation
Acai extracts have a similar but weaker action to non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and can reduce pain, stiffness and swelling by inhibiting COX-1 and COX-2 enzymes.
Acai and weight loss
In Brazil, acai berries are a popular addition to weight loss diets, partly due to the satiating effects of their fibre. Their main benefit is in reducing the inflammation associated with being overweight, however. In a study involving overweight men, consuming an acai berry smoothie that provided 694mg polyphenols, significantly improve blood vessel dilation compared with a matched control smoothie which may help to reduce the risk of developing a heart attack or stroke.
Another study involving overweight adults showed that taking acai berry pulp twice a day for a month improve fasting glucose and insulin levels as well as cholesterol balance.
A typical dose for acai berry extracts is 500mg concentrated, freeze-dried acai berry powder, equivalent to 4 grams (4,000mg) of whole fresh acai berries.
Acai berry powder can be sprinkled on cereals or added to smoothies and juice.
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