Ben Goldacre
Thursday September 2, 2004
The Guardian
· Time for a Johnny Ball kitchen science experiment, I think. I could have told you from the start that “Aqua Detox” was a scam, and a popular one at that. Why? Because it is claimed to extract “toxins” from your body through the “2,000 pores in your feet” discovered by those ancient Chinese scientists. And because it’s so charmingly theatrical: you put your feet in a water bath, containing “natural organic salts”, with an electrical current that “resonates” with your “bio-energetic field” passing across it, and the water goes first tea-coloured, and then properly brown, with a sludge on top. You think I’m making this up, but it’s been in the Daily Telegraph, and innumerable other places. So it must be true. And this brown, the Aqua Detox people proudly tell you, is from the toxins coming out of your body.
· Thinking back to GCSE chemistry, it seemed likely to me that it was rust rather than toxins, since they have, after all, got a pair of metal electrodes in a salt water bath with a current passing across them. And so we set up, on a kitchen table, a bowl containing salt and water, with two metal nails attached to a car battery. And what do you know: our water goes brown too, with a nice sludge on top. Could this be the same brown as the Aqua Detox water?
· Bravely I sent along my friend Dr Mark Atkins to have himself Aqua Detoxed. He took water samples from the bowl, which we sent off to the Medical Toxicology Unit at New Cross, south-east London. You can only imagine our excitement, especially as they charged us £200 for the analysis. And so – triumphant music – the water taken out before they switched their Aqua Detox machine on contained only 0.54mg per litre of iron (probably from the metal spoon); but afterwards it contained … 23.6mg/l. Our water, from our kitchen table setup, contained 97mg/l (and it was a bit browner).
· But did it extract toxins? “Toxin” is classic pseudoscience terminology. Essentially, the Aqua Detox people are offering dialysis, through your feet. Urea and creatinine are probably the smallest molecules – call them “toxins” if you like – that your body gets rid of, in places like urine and sweat: if “toxins” were going to come out, anywhere, you’d expect those to come out, too. There was no urea or creatinine in the water before the Aqua Detox, and there was none in the water afterwards. Which means, I believe, that we win.