According to a 2002 article in the
Seattle Times, there are two opposing viewpoints of anti-aging products. The article states that the first view is represented by scientists who publish their findings in the
scientific literature and who believe that no currently available intervention can slow or prevent aging. The alternative viewpoint is represented by people who the article states have "fewer credentials" and who promote a range of products that claim to have anti-aging properties. A similar observation was made by
Business Week in 2006, when they stated that although anti-aging medicine is increasingly popular, there is "precious little scientific data to back up their claims that the potions extend life." As an example of the first viewpoint, a 2004 review in
Trends in Biotechnology written by Leigh Turner of the
Institute for Advanced Study in
Princeton, New Jersey stated that the products promoted by the A4M have "no credible scientific basis" and that "there are no proven, scientifically established 'anti-aging' medications". A 2006 review published in the
Cleveland Clinic Journal of Medicine of the
antioxidants and hormones that are promoted as anti-aging products by A4M and clinics like the Palm Springs Life Extension Institute concluded that these products have "minimal to no effect on improving longevity or functional abilities." In an editorial accompanying this study, Thomas Perls stated that although many unjustified claims were made about anti-ageing products, no substance had yet been shown to halt or slow the aging process. Similarly, the
National Institute on Aging, who are part of the
National Institutes of Health, published a general warning in 2009 against businesses that claim anti-aging benefits for their products, describing these as "health scams" and stating that "no treatments have been proven to slow or reverse the aging process". The
Seattle Times quotes Klatz as describing those who doubt the validity of anti-aging medicine as "flat-earthers" who make unjustified criticisms that are not backed by scientific evidence, the article also states that Klatz "sees the science and medical establishments as out to get him." Members of the anti-aging movement have interpreted these results to support a role for growth hormone in slowing or reversing aging. A review in
The Journal of Urology noted that this promotion of growth hormone as an anti-aging remedy is "arguably similar" to ideas that date back to the late 19th century, when the physiologist
Charles-Édouard Brown-Séquard advocated rejuvenating hormone products prepared from animal testicles and stated that "the injections have taken 30 years off my life".
The New York Times reports that the idea that growth hormone can improve "health, energy level and sense of well-being." is a core belief of the A4M, A 2005 review in the
Journal of Endocrinological Investigation noted the long history of these ideas, but stated that the "concept of a 'hormonal fountain of youth' is predominantly mythological." Nevertheless, Klatz maintains that growth hormone reverses aging as a physical process and has described growth hormone as "the first medically proven age-reversal therapy." As a result of the reactions to the 1990 article and its frequent citation by proponents of HGH as an anti-aging agent, in 2003 the
New England Journal of Medicine published two articles that strongly and clearly stated that there was insufficient medical and scientific evidence to support use of HGH as anti-aging drug. One article was written by the
Journal's then-editor in chief, Jeffrey M. Drazen, M.D. and was entitled, "Inappropriate Advertising of Dietary Supplements". It focused mostly on the advertising of dietary supplements. The other article was written by the editor-in-chief at the time the 1990 article was published, Mary Lee Vance, M.D., and was entitled, "Can Growth Hormone Prevent Aging?"; it focused more on the medical issues around whether there was sufficient evidence to use HGH as an anti-aging agent. A 2007 review on the use of human growth hormone as an anti-aging treatment in healthy elderly people published in the
Annals of Internal Medicine concluded the risks of HGH significantly outweigh the benefits, noted
soft tissue edema as a common side effect and found no evidence that the hormone prolongs life.
ABC News interviewed Hau Liu of
Stanford University and lead author of the paper, who stated that people are paying thousands of dollars a year for a treatment that has not been proved to be beneficial and has many
side effects. Some small studies have shown that low-dose GH treatment for adults with severe GH deficiency, such as that produced after surgical removal of the
pituitary gland, produces positive changes in body composition by increasing
muscle mass, decreasing fat mass, increasing
bone density and muscle strength; improves
cardiovascular parameters (i.e. decrease of
LDL cholesterol), and improves quality of life without significant side effects. The extension of this approach to healthy elderly people is an area of current research, with a 2000 review in
Hormone Research commenting that "Clearly more studies are needed before GH replacement for the elderly becomes established." and noting that "safety issues will require close scrutiny". A 2008 review of the controversy surrounding the use of growth hormone in anti-aging medicine which published in
Clinical Interventions in Aging noted the opinions of the A4M on this topic, but suggested that high levels of growth hormone might actually accelerate aging. The
Clinical Interventions in Aging review also stated that although the decreasing levels of the hormone seen in the elderly might reduce quality of life, this change could protect from age-related diseases and cited evidence linking GH to cancer. This concern was mirrored in a 2008 review published in
Clinical Endocrinology, which stated that the risk of increasing the incidence of cancer was a strong argument against the use of this hormone as an "elixir of youth" in healthy adults. ==Legal disputes==