Goji berries are one of the better-known superfoods, and they are widely available in dried form in supermarkets, organic food stores and chemists.

They are reputed to be particularly good for you, but is there any truth in this?

Let’s start with a look at the nutrients you get from them.

“They contain many carotenoids, vitamin C, iron, calcium, but also fibre,” says Daniela Krehl from the Bavarian Consumer Advice Centre in Germany.

However, Krehl warns that because they are dried fruits, their sugar content is also high – up to 46%.

This means that goji berries are significantly higher in calories than other sources of vitamin C, such as sweet peppers or blackcurrants.

The berries are said to strengthen the immune system and have an anti-ageing effect, though there is no scientific evidence for this.

The European Food Safety Authority (EFSA) has found that there is no causal link between any claimed special health effects and eating goji berries, so these health claims are not allowed on advertising.

The Bavarian consumer advice centre says that goji berries are not suitable for everyone since they can interact with medication.

Goji berries can inhibit the breakdown of certain blood thinners, known as vitamin K antagonists.

This can result in a dangerous build-up of the active ingredient in the body, and in some cases, cause an increased tendency to bleed. – dpa