They promise youth, but supplements of human growth hormone are a dangerous dream. Vivienne Parry reports
Hormones, the chemicals that carry messages around the body, have always been pounced on by charlatans making extravagant promises about their rejuvenating powers. A century after the term “hormone” was first coined, every e-mail in-box in the land has its share of hormone spam, promising firmer muscles, fewer wrinkles and better sex.
But now there’s more cause to worry about the patter of the rejuvenators than ever before. Taking hormones to hold back the years is based on a myth. And, for people who have no medical need for hormone supplementation, swallowing the dream could hold fatal risks. Yet access has never been so easy. In the past decade, hundreds of companies have sprung up selling hormone products, evading national restrictions by promoting their products on the internet. You’d never be able to buy these products over the counter because their claims are unproven.
The flawed logic of the rejuventators is always the same. Since key hormones such as testosterone fall with age, restoring them to youthful rates will hold back the years. It’s an idea of seductive simplicity, with the potential of millions of pounds in profits.
The hormone that is the subject of the most longevity hype is human growth hormone (hGH). This prescription-only substance, or more usually the oral formulations claimed to promote its release, pop up frequently in medical spam. Google turns up more than three million websites for the hormone, and entry into any site prompts an explosion of claims for this “ fountain of youth”. Take one at random &emdash; a website for a product which offers “Advanced ageing therapy &emdash; now used by 1,000s worldwide”. The supplement, it says, safely uses “the results of 25 years’ research into human growth hormone secretagogues (growth-releasing formulae) and their effects on ageing”. It quotes a Dr Anthony Karpos: “We really have something here which may be able to reverse some of the problems associated with ageing.”
The truth about hGH is rather different. When, researching a new book, I took one of these oral formulations to be tested, it had no effect whatsoever. What’s more, the injections of the hormone favoured by body-builders carry serious risk to human health, even Creutz- feldt-Jakob disease (CJD), the human form of “mad-cow” disease.
In its place, growth hormone has a vital role. It is responsible for growth in childhood and has many other biological effects, including carbohydrate and fat metabolism. Produced by the pituitary gland, it peaks in adolescence &emdash; the rate at which it is secreted in a 60-year-old is half that in a 20-year-old. It is released mainly at night but is also prompted by exercise, eating and trauma.
About one in 5,000 children has growth hormone deficiency, and some adults also become deficient after accidents, surgery or radiotherapy. They need injections of synthetic growth hormone &emdash; an expensive business costing up to £20,000 for a year’s provision.
What propelled growth hormone to superstar anti-ageing treatment was a study published in 1990 in the world’s leading medical journal, the New England Journal of Medicine. This was a small case study of 12 elderly men, by Dr Dan Rudman, a physician from Wisconsin, who gave them three shots of high-dose growth hormone a week for six months. It noted a reduction in fat and an increase in lean body tissue and skin thickness, a finding not repeated since.
No matter. It was a call to arms for the American anti-ageing industry, which used the study to peddle all manner of growth hormone “preparations” to hold back the years. If the industry had tried to advertise their products in magazines, or to sell them in shops, it could never have made such claims. Strict regulations cover these areas in the United States and United Kingdom, and all medical claims have to be backed with science.
But the twilight world of the internet often escapes the jurisdiction of specific countries, and the claims made for growth hormones escalated &emdash; particularly in the anti-ageing-obsessed US. Most of the products weren’t injectable hormone as used in the Rudman study, just oral supplements supposed to promote its release.
The editors of the journal were appalled, and it’s now become impossible to download the paper without a stern commentary denouncing growth hormone as an anti-ageing treatment. Extensive work from Scandinavia has shown that injecting the hormone does not restore muscle mass or fitness to the elderly.
Growth hormone is a protein; it is destroyed if given by mouth. Even so, knowing that injections aren’t popular with the punters, many rejuvenators offer oral secretagogues, the so-called growth-hormone releasing formula. These typically contain a range of amino acids. One such is arginine, which is used by endocrinologists testing for GH growth hormone deficiency. A cup of strong Bovril (which is rich in arginine) should prompt a small release of growth hormone, but the point is that this is short-lived, and repeat doses produce decreasing levels of response.
John Wass, professor of endocrinology at Oxford University, recently tested one of these products for me &emdash; I’d been sent it as a free sample, but I could just as easily have bought it off the internet. He measured levels of growth hormone before and after the supplement to see if it had any effect. It didn’t provoke even a flicker.Yet it cost £60 for a month’s supply &emdash; which is fairly standard &emdash; and such products are sold in their millions.
Professor Stafford Lightman, at endocrinologist at Bristol University, who speaks for the Pituitary Foundation, is appalled.
“It’s totally unethical to be selling something on the ground that it does something when it doesn’t,” he says. “It’s simply taking people for a ride.” Lightman is categorical: these products do not work.
Two years ago, the US Food and Drug Administration started to get tough on growthhormone peddlers in America. A company called Nature’s Youth was forced to destroy $500,000 worth of stock because it could not substantiate its claims, which were promoted by G. Gordon Liddy &emdash; a man some may remember from his part in the Watergate conspiracy. Hundreds of other firms continue their trade uninterrupted.
The supposedly hormone-producing formulations may not do any good, but there’s no evidence that they do any harm. But for those who can find, and take, the real thing as injections there can be dangerous side-effects, unless they are genuinely growth hormone deficient; among them a bone-distorting condition called acromegaly, diabetes and, ironically, weak muscles.
Bodybuilders and athletes believe that growth hormone builds muscle. But as Professor Mike Rennie, a muscle physiologist at Nottingham University, points out: “The evidence that short or long-term administration of growth hormone alone, with other steroids or in combination with training, has an effect on muscle protein manufacture, weight or strength in healthy young-to-middle-aged humans is very slim indeed.”
What does happen is a change in body composition which gives more definition or “cut”, which makes athletes believe it works.
Worryingly, researchers in reputable sports science journals are now expressing fears that, faced with the high cost of synthetic growth hormone and a Europe-wide ban on growth hormone extracted from human bodies (the usual source until 1985), some athletes are obtaining growth hormone extracted from human cadavers outside Europe. There is a risk of CJD. If those using the hormone have surgery, hospitals should know so they can take safety measures. But they don’t, which puts at risk other patients treated with the same instruments.
The truth is that if you don’t smoke, if you exercise regularly and eat a low-fat diet of foods with a low glycaemic index, the chances are good that you will sail your way into your seventies and eighties with clear brains and good muscles. You don’t need hormones to pump new life into you.
Vivienne Parry is the author of The Truth About Hormones (Atlantic Books, £9.99). She will be speaking on this subject on June 8 at the Cheltenham Science Festival (01242 227979), June 8-12.
Contact the Pituitary Foundation on 0845 4500375; www.pituitary.org.uk
Hormone type
Testosterone
Transplantation of animal testicles made a fortune in the 1920s for many, including John Romulus Brinkley, a US doctor who implanted goat testicles into thousands of willing men. Yet the evidence that testosterone is not associated with long life is all around us. Women live on average ten years longer than men, with testosterone-deprived eunuchs not far behind.
DHEA (the male hormone dehydroepiandrosterone)It too, falls with age, with the steepest decline in people’s middle years. When levels of DHEA were shown to be linked to lifespan, the internet DHEA goldrush began. But there is zero evidence that the hormone restores strength and vigour.
