Popular among celebs from Madonna to Miranda Kerr, goji berries have been used in Chinese medicine for more than 6,000 years.
These shrivelled red berries are alleged to boost the immune system and brain activity, protect against heart disease and cancer, and improve life expectancy.
Goji berries contain vitamin C, vitamin B2, vitamin A, iron, selenium and other antioxidants (notably polysaccharides).
We've teamed up with the British Dietetic Association (BDA) to examine whether the health claims about goji berries are supported by the evidence.
The evidence on goji berries
Can goji berries improve immunity, cardiovascular disease and life expectancy?
There is no reliable evidence to support these alleged health benefits. Most of the research into these conditions are small-sized, of poor quality, and performed in laboratories using purified and highly concentrated extracts of the goji berry.
Do goji berries aid wellbeing, brain activity and digestion?
One small study from 2008 found a daily drink of 120ml of goji berry juice for 14 days improved feelings of wellbeing, brain activity and digestion. However, the study involved only 34 people and was attempting to measure the effects of goji berry juice on a variety of conditions. The results of the study were inconclusive.
Can goji berries prevent cancer?
One of the most talked about clinical studies on goji berries is a 1994 Chinese study conducted on 79 patients with various advanced cancers. It found those treated with immunotherapy in combination with goji polysaccharides saw their cancers regress. Unfortunately, information on the design of the study and the goji berry compounds used are lacking, so it is difficult to fully assess the significance of the results.
The dietitian's verdict on goji berries
Alison Hornby, a dietitian and BDA spokesperson, says the evidence behind the health claims about goji berries is weak.
She says: "Various goji berry products are sold as health foods, but the evidence of their health benefits so far comes from scientific studies using purified extracts of the fruit at much higher concentrations than the products contain.
"As these products tend to be relatively costly, it makes sense to stick to eating a range of fruits and vegetables rather than spending your money on this one item with no proven health benefits."
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Check out the evidence behind the health claims of these other so-called superfoods:
Article provided by NHS Choices