Whilst reading a book called The New Science of Perfect Skin, I came across a new ingredient: ergothioneine. According to the book's author, Daniel Yarosh PHD, ergothioneine is one of the few antioxidants (along with vitamins, A, C and E) with any strong evidence behind it to suggest that it works. I was intrigued.

Ergothioneine is an antioxidant amino acid that occurs naturally in the body and is found in high concentrations around cells that are subjected to free radical damage. However, we can't synthesize it, so we need to obtain it from our diet. Please don't tell me it can only be found in broccoli or brussel sprouts.

Mercifully for us brocolli haters, white button mushrooms contain 12 times more ergothioneine than does wheat germ and four times more than chicken livers, according to Penn State food scientists. Portabellas and criminis have even more. The more exotic your fungi, the more ergothioneine, with hen's of the woods or shitake having 40 times more of it than wheat germ.

I was starting to fantasize about mushroom risotto when I started to smell the whiff of a rat around this study. Perhaps it was the - to me anyway - rather bizarre comparison by the researchers of mushrooms to chicken livers. The nasty, old cynical harridan in me began to wonder if there is was any connection between Pennsylvania and mushroom production. Ha, gotcha! Turns out Pennsylvania is the biggest producer of mushrooms in the United States and the Penn study was funded by the state's Mushroom Endowment Fund. A self-serving of fungi, anyone?

A German study does, however, back up the mushroom theory and also says ergothioneine can be found in kidney, liver, red and black beans and oat bran. The problem is that the Germans aren't so convinced that ergothioneine is all that great in the antioxidant department, saying that it only protects against copper (II)-induced toxicity. On the other hand, a Scottish study at the University of Edinburgh, concluded that it is an effective antioxidant and anti-inflammatory.

I also found a patent application for using ergothioneine as a preservative. Now there's a good, but all too rare, idea: a preservative that does good rather than evil.

It wasn't long before I came across another couple of research papers, one of which claims that ergothioneine is a much better antioxidant than idebenone. They are both authored by Daniel Yarosh PHD. I had come full circle. Mr Yarosh's company, AGI Dermatics, has registered a ergothioneine derivative called thiotaine. It is used in products by Remergent, a company that AGI Dermatics owns.