What is ergothioneine?
L-ergothioneine is a naturally occurring sulphur-containing amino acid derived from histidine. It was first identified in 1909 by the French pharmacist Charles Tanret in ergot of rye (Claviceps purpurea). Humans cannot make it – it is produced by certain fungi and soil bacteria – so we obtain it from food.
Interestingly, the human body has a specific transporter (called OCTN1) that takes ergothioneine into cells, and it is found in many tissues, including red blood cells, the liver and the eyes. This is why it has become an active area of scientific research.
Where is it found?
Mushrooms are the richest dietary source. Species such as Oyster Mushroom, Shiitake, Lion's Mane, Chaga and Cordyceps are notable for their ergothioneine content. Smaller amounts are found in some meat, fish and shellfish.
What is research looking at?
Scientists are studying ergothioneine's role in cells and how its levels change with age. Most of this research is at an early stage, and there are currently no authorised health claims for ergothioneine.
Other compounds in mushrooms
Mushrooms also naturally contain ergosterol (a precursor of vitamin D2), polyphenols and beta-glucans.
Including a variety of culinary mushrooms in a balanced diet is the simplest way to enjoy them.