The trouble with much medical research

The consequences of ageing, including wrinkles and - allegedly - diminishing libido, are no longer time-associated inevitabilities but life events of choice. At least according to Jeya Prakash, a Harley Street cosmetic surgeon, who says that after months of injecting growth hormone into himself and his wife, they have turned the clock back. He and his wife, he says, feel young again.
I feel bad for mentioning this because when a medical myth is repeated enough, it develops an unsinkable status hingeing on the fact that it "might" work. And since we're all into professing our frequent clinical uncertainties, who's to say that a little growth hormone might not just, literally, save
Let us rewind to the paper in the New England Journal of Medicine that stands accused as the source of the anti-ageing claims for growth hormones. Register and read the paper for free. There is, of course, no proof of a miraculous effect anywhere.
The paper is called "Effects of Human Growth Hormone in Men Over 60 Years Old" and was published in 1990. The measurements of lean body mass, adipose tissue mass, skin thickness and bone density were taken before and after six months of growth hormone injections. The men were leaner and thinner, their bones denser and their skin thicker - although not all of these results reached statistical significance.
The reason I'm mentioning this study is it makes some telling points about the way we use and misuse clinical science.
First off, note that the trial didn't actually measure anything relating to either perceived or actual quality of life, never mind wrinkles. Does it matter if a medication can increase your bone density by 2.3 per cent? Exactly what is the effect, in real-life terms, of increasing your skin thickness by 7.1 per cent?
We don't know. This initial study might have been quite interesting but it is here that big-time, powerful, placebo-controlled, blind studies should have been initiated. In other words, this is not a study to base a growth hormone industry on, a point that seems to have been lost post-publication.
The NEJM accompanied the 1990 paper with an editorial, saying much the same thing. It took until 2003 for another editorial to appear, this time with the results of a couple of other studies examining the effect of growth hormone, concluding once more that there was no proof behind anti-ageing claims.
This is the first troubling thing about so much medical research. The findings may be far from conclusive and it often doesn't measure what it would be very helpful to know.
Second, we are apt to get excitable about things that are not exciting. In fact, the whole MMR scare grew out of a paper that was similarly observational and involved a small number of patients who grew the measles virus from gut tissue.
This does not mean small studies shouldn't be published - au contraire. If a well-designed study is done the results should be available. But, as with the tomes of initial findings published every day, we need to follow research up with better, fairer and bigger studies to find more certain answers.
Preferably, we could do better again if we could set out to answer questions we really want to ask. Bottom line - is MMR safe? Fabulously large, long-term studies say with high amounts of certainty that yes, it is.
What of growth hormone? The question is not just about safety or even bone density and adipose tissue but about how it makes us feel. Does it make our wrinkles fade and our libidos sparkle? No evidence at all.
In fairness, in marketing itself as a "possible" relief for ageing, growth hormone is no worse than the shelves of other pseudo-medical substances that don't work and are allowed to make similar soft claims.
From most cough bottles to certain eye drops and the vast majority of multivitamins and detox supplements, all are allowed to say that they "may" have clinical effects.
Even homeopathic medicines, under recent changes from the Medicines and Healthcare Regulatory Authority, are allowed to state what they work for in the "homeopathic tradition". This is despite the lack of evidence for homeopathy in either biology or clinical trials. The MHRA say that homeopathic medicines will be licensed for "self-limiting conditions". (That's a clue - it means the condition was going to get better anyway.)
But what about remedies, say, for HIV or Aids that "might" work - like the alleged but nonsensical treatments for HIV such as vitamins, lemon, garlic or beetroot, which are heavily promoted by some political leaders in Africa when we know it is antiviral drugs that are capable of turning HIV from death sentence to chronic disease?
Doctors should be honest about what doesn't work - and that includes a lot of conventional medicines. But there is a difference between something that we know will work sometimes and where there is no evidence at all.
It's much harder - some say impossible - to prove a negative. But no one should be allowed to make even tentative claims for medicines without decent proof.

By Margaret McCartney (GP, Glasgow) / Published: September 9 2006 / Copyright: The Financial Times Limited 2006