Viv Godfrey of Palmerston North asks :-

I am thinking of taking "Body Enhance Plus" for muscle tone and improving hair and skin, and "Memory Power capsules" to improve my memory. Will these products help or am I wasting my money?

John Welch, a Marlborough medical practitioner (ex RNZAF) who has studied similar claims, responded.

I found many testimonials to these products but no studies that met current standards of scientific proof. It is an unfortunate fact that testimonials are a hallmark of unproven and often quack remedies. I therefore searched websites devoted to exposing quackery such as www.quackwatch.com and www.ncahf.com but found no reference to these treatments.

At best these products are unproven and any claims should be treated with scepticism. As a doctor I can confidently state that if I found scientific evidence that these products really worked then I would recommend them to my patients and I would take them myself to prevent those occasions when I have mislaid my car keys or have a pessimistic viewpoint on my fitness. I suspect that you are close to the truth when you said, 'am I wasting my money.' If I am proved to be wrong in this assessment I will be happy to eat my hat, live on national television.

This is how I would test the claim that "Memory Power" capsules improve memory. In an experiment, scientists randomly assign people into two groups. One group gets the real "Memory Power" capsules and the other group gets a placebo (ie. dummy) capsule which looks and tastes exactly the same as the real "Memory Power" capsule. Neither group knows which sort of capsule they have got. It is preferable that the scientists organising the experiment don't know as well and it is normal practice to conceal this information. At the end of the experiment all of the subjects get a memory test to see if there has been any improvement. At the very end of the experiment the scientists are allowed to see who got what and whether it helped their memory. If there is no difference between the two groups we can say that "Memory Power" capsules are a placebo. Any perceived benefit is therefore due to wishful thinking and expectation. These sort of experiments are carried out all the time and are known as "double blind placebo controlled trials" and they are the only way of settling such claims.