Older people trying to stave off the natural effects of aging should exercise their minds and bodies rather than rely on drug treatments, several new studies say.
Researchers reporting in today's Journal of the American Medical Association found that older adults who received training in memory, reasoning and mental speed showed significant - and lasting - improvements, suggesting a way to slow or reverse normal declines in thinking ability.
Another study found that postmenopausal women who engage in moderate physical activity such as walking have a substantially reduced risk of hip fracture, which frequently leads to fatal complications in the elderly.
At the same time, researchers in a third study raised serious questions about seniors' use of human growth hormone and sex hormones, saying they can make people leaner but also can cause diabetes, joint pain and other problems.
"In many cases, pharmaceuticals don't seem to provide the answer that people are looking for in reversing the effects of aging or in preventing the detrimental effects of aging," said Dr. Margaret A. Winker, deputy editor of JAMA, which published the findings in a special issue on aging. "The greatest benefits seem to come from the things we know more about - like exercise."
The mental training study dealt with exercise of the brain. The trial included 2,832 adults ages 65 to 94 in six areas across the country, including Maryland.
Most participants were randomly assigned to one of three groups for training in memory, reasoning or speed of processing, while those in a fourth got no training. Some volunteers learned tricks for remembering word lists or details in stories; others practiced picking out pictures that flashed increasingly fast on a computer screen.
The training, which was administered over five or six weeks, consisted of 10 sessions lasting from 60 to 75 minutes.
The study found that 87 percent of those trained in speed and 74 percent trained in reasoning showed "reliable improvement" in tests immediately afterward. About a quarter of those trained in memory improved. People who received "booster" training about a year later did even better in reasoning and speed.
Researchers were encouraged by the findings not just because the training was successful in improving mental abilities, but because the effects lasted - though at lower levels - even two years later. The improvement was enough to more than offset the mental decline normally expected over a seven- to 14-year period in elderly people not suffering from dementia.
"One of the messages is that you can maintain or improve your thinking ability the same as you can your physical ability," said Karlene Ball, a psychology professor at the University of Alabama at Birmingham and lead author of the study.
The study did not attempt to gauge whether the exercises improved daily functioning. But one of the trial's principal investigators, George W. Rebok, said the training targeted mental abilities needed for everyday activities, including taking medication, using the telephone or reading traffic signs.
"That will really be our next challenge: to see how much of these gains really translate into older adults' ability to perform these everyday tasks," said Rebok, an associate research professor at the Johns Hopkins Bloomberg School of Public Health.
In a separate JAMA study, researchers reported on the effects of anti-aging medications, including human growth hormone - which, by some estimates, upward of 10,000 baby boomers and elderly patients have been taking in an attempt to slow the aging process.
Doctors at the Hopkins School of Medicine and the National Institute on Aging found that injections of the growth hormone made elderly men and women lose fat and gain muscle. The improvements in body composition were even greater for men who also received testosterone, a male sex hormone. Though the men didn't get stronger, the combined therapy enabled them to exercise longer without tiring.
But the hormones brought risks serious enough for the researchers to warn people against using them as anti-aging treatments outside of clinical trials.
Almost half the men who received growth hormone developed diabetes or glucose intolerance, a precursor to diabetes. More than a third of the women taking growth hormone - with or without the female sex hormone estrogen - developed swelling of the arms and legs. And a third of men taking growth hormone and testosterone developed carpal tunnel syndrome, a nerve problem that causes numb fingers and wrist pain. About 41 percent of men taking growth hormones developed joint pain.
"This is not ready for prime time," said Dr. Marc R. Blackman, a former Hopkins endocrinologist and one of two study directors who is with the National Institute of Complementary and Alternative Medicine in Bethesda.
The study is sure to rekindle the growing debate over the safety of hormone treatments. In July, researchers reported that post-menopausal women who were taking sex hormones - estrogen and progestin - had an increased risk of heart disease, stroke and breast cancer. Doctors recommended that women take them for the relief of hot flashes and other symptoms of menopause, but not for the long-term prevention of disease.
Blackman and Dr. S. Mitchell Harman, now with the private Kronos Longevity Research Institute in Phoenix, started the anti-aging study in the early 1990s to test the theory that men and women could stave off the effects of aging by replenishing hormones lost as they grow older.
A few years earlier, doctors at the Medical College of Wisconsin touched off a surge of interest in "anti-aging" medicine when they reported that growth-hormone injections caused men to lose fat and gain muscle and skin tone, making them feel 10 to 20 years younger.
In their study, Blackman and Harman recruited 131 elderly men and women and randomly assigned them to receive combinations of growth hormone, sex hormones and placebos. Participants took the medications for 26 weeks.
The doctors noted that the hormones didn't produce noticeable changes in physique, though participants taking them said they felt more vigorous. The benefits were comparable to what would be achieved in a program of vigorous exercise, producing a 10 percent shift in body composition away from fat.
The side effects disappeared when treatment was stopped, but researchers said they were concerned that patients could suffer dire effects - particularly from diabetes - if treatment were long term and poorly monitored.
"The anti-aging-medicine doctors subscribe to the idea that it is better to try almost anything that even looks promising now because later it will be too late for the people who are coming to them to benefit - the aging process having taken its toll," Harman said. "What they are forgetting is that the first rule for the physician should be ... 'first, do no harm.'"
Doctors practicing anti-aging medicine bristled at the suggestion that they might be hurting their patients, saying they can reverse any side effects by lowering hormone doses. They also said the researchers used doses that were far greater than those used by responsible physicians.
Dr. Dean Kane, a Pikesville plastic surgeon who also prescribes anti-aging hormones, said he tests his patients' blood levels every three months and monitors symptoms regularly to achieve the right balance of hormones.
"When the body itself is well-balanced with the proper levels and proper balance of hormones, it works extremely efficiently, like a youthful patient in his 30s," he said.
Kane said he was dismayed by the reports of side effects. "Those concerns are very simple to manage by changing dosages," he said.
Dr. R.W. Noble, a Dallas physician, said he started taking testosterone four years ago and added growth hormone last year. Now, at 76, he says he feels stronger and more vigorous than he has in years.
"I get up at 4:30 in the morning and go to bed around 10:30 at night," said Noble, who appears shirtless and barrel-chested on his personal Web site. "I don't feel old anymore."
In the walking study, researchers reported that hormone replacement therapy was associated with lower risk of fractures. But so was regular, moderately paced walking. And taking hormones did not appear to further reduce risk among the most active women.
In a JAMA editorial, Dr. Christine A. Cassel, dean of the Oregon Health Sciences University School of Medicine and an expert in geriatrics, said patients and doctors often look to medication - rather than behavioral changes - to improve health. "Ironically, better evidence supports the simple combination of physical, cognitive and social activities to achieve positive outcomes that elude hormone therapies and many other pharmacological interventions," she said.