I am glad to see you writing about John Diamond. I have written several letters to the newspapers to redress the balance a little after reading outrageous reviews such as 'he knew it was all untrue' about alternatives. (He didn't seem to have done any proper research - just chatted to friends and, no doubt, the medical profession).
The point I would like to make is that he was wrong right from the title Snake Oil.
Now accepted as a synonym for a useless con, snake oil (especially Chinese water snake) is the richest source of EPA (omega-3) in the world. Even the medical profession now advises an increase of omega-3 fats for many complaints (as mentioned in Fats That Heal, Fats That Kill by Udo Erasmus).
I am surprised no mention was made of magnesium in reply to your correspondent with cramp (WDDTY vol 12 no 5, Q&A). Cramp is a classic sign of magnesium deficiency, which is very common.- Helen Jarvis, Ilkeston, Derbyshire