New Research in Aging
This discussion originally aired on October 19 as part of SOUNDPRINT's Science You Can't
moderator @ soundprint2.brandywine.america
Host Bob McDonald of the Canadian Broadcasting Corporation will be chatting with guest Dr. Calvin Harley, a researcher with the Geron Corporation in California.
Hello everyone, welcome to our webchat on aging. This year, someone will be turning 50 every 90 seconds, so the topic is a popular one. Scientists around the world are working on various ways to reverse the aging process. How far can science go, and is that the right direction?
My guest is Dr. Cal Harley Chief Scientific Officer for the Geron Corporation, a Biotechnology company in Menlo Park California. Hello Dr. Harley.
Calvin Harley @ host43.geron.com
Hello, Bob. Good to talk (etalk?) with you again.
Q. First of all Dr. Harley, what research are you doing to reverse the aging process?
AGING FACT: In Canada this year, someone will be turning fifty every ninety seconds. That's 960 people a day. They're part of the first wave in the aging of the baby boom generation. Thirty five years from now, one in five Canadians will be over 65, and more than a million will be over 85.
Calvin Harley @ host43.geron.com
We are trying to address age-related diseases in humans through the fundamental mechanisms of cellular aging. This involves understanding the limited lifespan of normal somatic (body) cells, and the changes which occur when these cells senesce, or reach the end of their lifespan.
Bob McDonald @ cache1.cc.interlog.com
How close are you to actually reversing aging?
Calvin Harley @ host43.geron.com
We are still in the early days of understanding the basic mechanisms. However, we are in the "drug discovery" phase regarding skin aging. We are trying to find small, drug-like molecules which reverse some of the destructive changes which occur in skin cells when they senesce.
Other, earlier stage research at Geron involves the role of telomeres, the essential genetic at the ends of the chromosomes and how these elements shorten with age and what the consequences are.
Bob McDonald @ cache1.cc.interlog.com
What happens to the cells in our body as we grow older?
Calvin Harley @ host43.geron.com
Two things: they run out of their capacity to divide, and they change the patterns of proteins they make. We call the latter, "senescent gene expression". Both of these events contribute, we believe, in a significant way to loss of tissue function, and disease.
Bob McDonald @ cache1.cc.interlog.com
So how can you stop that from happening?
moderator @ soundprint2.brandywine.america
AGING FACT: By the age of 75, the average pair of feet will travel a distance equal to three trips around the world... about 288,000 kilometres.
Calvin Harley @ host43.geron.com
Let me address cell lifespan and senescent gene expression separately. Cell lifespan, we believe, is controlled in part by the rate of telomere loss. If we can manipulate the enzyme which synthesizes telomeres (the enzyme is called telomerase), then we might be able to
increase the cell's lifespan. Interestingly, telomerase is normally present only in the reproductive tissues, some "stem-like cells" and in cancer. Senescent gene expression can be addressed by conventional drug discovery: find a compound that reverses it.
Bob McDonald @ cache1.cc.interlog.com
Science is one thing, what about lifestyles, couldn't people live longer by simply taking care of themselves better?
AGING FACT: We are born with about 300 bones. But as we grow many of them fuse together, so that by the age of 25, we're left with 206. Despite its solid appearance bone is constantly changing... an endless cycle of breaking down and reforming. At any one time as much as 15% of our bone structure can be in flux. The reason is calcium. Virtually every cell needs it, and enzymes are constantly breaking down bone to provide a steady supply through the blood stream. But by the time we reach the age of 50, there's more bone being broken down than created.
Calvin Harley @ host43.geron.com
Lifestyle, diet, mental health & attitude are all important and many studies demonstrate an effect on reducing morbidity and mortality. However, there is still an underlying, genetic basis for aging which the best lifestyle, diet, and occupation cannot alter. Many of us will die prematurely because of cancer or susceptibility to specific diseases.
Bob McDonald @ cache1.cc.interlog.com
So that's the reaseach at the level of the cells in our body, how else is science trying to combat aging?
Calvin Harley @ host43.geron.com
We focus on cellular aging, but other groups are looking at effects of hormones, effects of oxidative damage, effects of free radicals and DNA mutation. These are all interconnected and complementary approaches. In fact, we feel that the reason some of these mechanisms have their greatest impact through accelerating the basic aging process of cells.
Bob McDonald @ cache1.cc.interlog.com
How far could science extend human lifespan?
moderator @ soundprint2.brandywine.america
from NOAH (New York Online Access to Health Website :
Most physiologic changes that do occur with aging do not cause disability in and of themselves. But aging decreases the the body's ability to withstand stress as homeostatic mechanisms decline in terms of functional capacity and ability to respond to stress, in a linear
fashion beginning in the late teens or certainly beginning by age thirty.
Calvin Harley @ host43.geron.com
That's a great, and controversial, topic. Scientists differ wildly in what they "believe" in this area, because for humans, it is in the realm of speculation. In invertebrates (worms, flies...) and in mice, genetic selection, genetic manipulation, and diet have all demonstrated dramatic impact on maximum lifespan. However, we I believe that in long lived animals like humans, it is going to be very difficult to increase maximum longevity significantly beyond the current limit of about 120 years. Most of us would be very happy to have an increased health-span that takes us into our 80s or 90s with mental and physical vigor.
Bob McDonald @ cache1.cc.interlog.com
If it is possible to strengthen the body, what about the mind, can it keep up with extra years of work if the body lasts longer?
moderator @ soundprint2.brandywine.america
From the National Insitute on Aging:
The normal processes of aging are a rich territory for medical quackery. In a youth-oriented society, quacks find it easy to promote a wide variety of products. They simply say their products can stop or reverse aging processes or relieve conditions associated with old age.
While there are products that may reduce wrinkles or reverse baldness for some people, these products cannot slow the body's aging process. However, not smoking, eating a healthy diet, and getting regular exercise may help prevent some diseases that occur more often as people age.
Calvin Harley @ host43.geron.com
Actually, the mind is extremely robust, and provided we are not susceptible to Alzheimer's disease, and provided we "exercise" the brain (life-long education), our minds can keep up. Some of us, however, will suffer various neurodegenerative diseases and stroke. These processes have a basis in cellular aging. So again, medicine of the 21st century may provide breakthrough therapies to keep our minds healthy.
Bob McDonald @ cache1.cc.interlog.com
Other scientists have stated that it may be possible to extend human lifetime to 150, even 200 years. What about the social impacts of having so many geriatrics hanging around?
moderator @ soundprint2.brandywine.america
From NOAH: "Alzheimer's disease is a degenerative disease of the brain from which there is no recovery. Slowly and inexorably, the disease attacks nerve cells in all parts of the cortex of the brain, as well as some surrounding structures, thereby impairing a person's abilities to govern emotions, recognize errors and patterns, coordinate movement, and remember. In the end, an afflicted person loses all memory and mental functioning.
Calvin Harley @ host43.geron.com
As I mentioned, I do not believe that there will be a quantum jump in maximum human longevity in the near future. However, we do need to be thinking about the social impact of health care costs and increases in average lifespan. This has been a trend through out this century, and it will continue.
Bob McDonald @ cache1.cc.interlog.com
Dr. Harley, what do you think about people like George Burns, who live to a very old age while smoking, drinking and generally leading "unhealthy" lifestyles?
moderator @ soundprint2.brandywine.america
From NOAH: Until recent years, Alzheimer's disease was nearly always diagnosed in people under 65; older persons who became confused or forgetful were thought to be victims of natural aging. It is now known that Alzheimer's is much more common in the elderly than was originally thought. An estimated 5% to 7% of people over 65 have Alzheimer's disease, and about 20% over 80 develop it. Currently four million Americans are diagnosed with Alzheimer's. Over the next decade, it is expected that Alzheimer's will become the fourth or fifth leading cause of death.
Calvin Harley @ host43.geron.com
Well, I liked George Burns. His lifestyle and longevity underscore the importance of our "genotype"--the importance of genetic determinants in how well we handle physiological insults, and what diseases we are susceptable to. That is why we need to understand these basic genetic determinants, and use that information to increase our health span. We probably all know some people who live a tremendously healthy lifestyle, yet die of cancer or atherosclerosis in their 50s or 60s.
Bob McDonald @ cache1.cc.interlog.com
What do you think of the "Anti-Aging" creams, laser treatments and other aproaches that are being advertised to heavily in the media?
moderator @ soundprint2.brandywine.america
from the National Institute on Aging:
Scientists are isolating genes believed responsible for the onset of age-related diseases, as well as those conferring health and longevity. Other areas of interest are the modifications proteins
undergo with age; control of cell proliferation; biomarkers of aging; relationships between healthy aging and disease; effects of aging on the body's immune, endocrine, and other physiologic systems; the neuropsychology and cognitive psychology of aging; and lifestyle factors affecting health and disease, such as diet and exercise.
Calvin Harley @ host43.geron.com
Buyer beware. Some products and treatments might be valid and proven. However, as a scientist, it disturbs me to see so many products being sold to treat aging and age-related conditions, without any properly controlled studies. Too many probably do more harm than good. There is a reason for clinical trials: products should be effective, and they should be safe.
moderator @ soundprint2.brandywine.america
AGING FACT: Nowhere in our bodies are the effects of aging displayed quite so visibly as on our skin. And the struggle to eliminate the ravages of skin aging goes back to the beginnings of recorded history. The ancient Egyptians and Greeks used anti-wrinkle creams. Queen
Elizabeth I kept her complexion attractively pale with lead paint and alabaster. But cosmetics only hide the lines and wrinkles caused by age. The real goal has always been to stop the skin from aging.
Bob McDonald @ cache1.cc.interlog.com
Larry, your observation that the science of aging seems to berelated to certain social classes is an old idea. Historically, it has always been the rich who benefit from aging technologies, something to be considered for the future...if science succeeds in prolonging human life, how expensive will it be and who will benefit?
Calvin Harley @ host43.geron.com
There are several questions here. First, aging is not genetically programmed, it is under genetic influence. There is no "altruistic" reason for aging, it is a consequence of many processes which are adaptive early in life, but maladaptive late in life. Dozens, if hundreds of genes are likely to be involved in humans.
In the next 20 or 30 years (perhaps longer), we can focus on medicines to treat diseases. How expensive they are, and who receives them, is constantly under consideration by social scientists, the public, and politicians.
Bob McDonald @ cache1.cc.interlog.com
Is it possible that science is being used as an excuse for bad habits? In other words, are we hoping that we can continue to abuse ourselves, then take a "magic bullet" the day after?
moderator @ soundprint2.brandywine.america
ernesto montilla @ sp6.brandywine.american.edu
How many years in the future are we talking here, and do you think that there is some sort of "holy grail" for aging slowage, or more likely are we talking about a series of small steps over many many years...
moderator @ soundprint2.brandywine.america
from the National Institute on Aging:
NIA-funded research seeks to identify genetic and environmental factors associated with aging processes. Scientists are isolating genes believed responsible for the onset of age-related diseases, as well as those conferring health and longevity. Other areas of interest are the modifications proteins undergo with age; control of cell proliferation; biomarkers of aging; relationships between healthy aging and disease; effects of aging on the body's immune, endocrine, and other physiologic systems; the neuropsychology and cognitive psychology of aging; and lifestyle factors affecting health and disease, such as diet and exercise.
moderator @ soundprint2.brandywine.america
larry @ soundprint.brandywine.american
Is there anything we learn from looking at long-lived animal species?
Calvin Harley @ host43.geron.com
I hope science and medicine are never used as an excuse for bad habits. Most of us do not want to get sick, whether it is an acute, non-age-related problem (an infection, for example), or a consequence of aging. We should use good judgment and common sense to avoid illness, and when that fails, it is a blessing to have medicine.
moderator @ soundprint2.brandywine.america
from the National Insitute on Aging:
Adequate nutrition is important to ensure good health throughout life. In this area, researchers are studying changes in the ability of older individuals to taste and smell, changes in their eating patterns, and metabolic disease (such as diabetes) or dietary factors that are associated with depressed immunocompetence and cognitive function. Research in exercise physiology is designed to assess the effects of physical activity on the health of older people, as well as the ability of exercise to prevent physical decline and various diseases-including diabetes, hypertension, osteoporosis, and stroke.
Bob McDonald @ cache1.cc.interlog.com
How long will it be before we see the anti-aging technologies out of the experimental stage and into the hands of the aging population?
Calvin Harley @ host43.geron.com
Larry: comparative biology does help us identify the genetic determinants of aging: cell lifespan, handling of DNA damage, oxidative damage, hormonal changes....
Bob McDonald @ cache1.cc.interlog.com
We hear about the effects of ultra violet radiation on the skin, and links to skin cancer, how much is UV Radiation related to aging in gen eral?
Calvin Harley @ host43.geron.com
UV damage causes DNA damage, which in turns changes gene expression and accelerates cell aging. Skin from the sun-exposed parts of the body age faster and have more signs of "senescent gene expression".
Calvin Harley @ host43.geron.com
How long before we see new treatments/therapies for age-related disease? New products are coming onto the market all the time. Most address the symptoms of disease. It may be 5, 10, 15 years or more before we have safe and effective therapies that attact the basic process of cellular aging. We don't know, and it is extremely difficult to predict.
moderator @ soundprint2.brandywine.america
From the Mayo Health Oasis:
From long experience, doctors and researchers are skeptical of so-called miracle cures. They point out that most early claims are based at best on animal or laboratory experiments. Melatonin's effects on humans are still largely unknown or unproven.
It is true that melatonin has had some striking effects on rats and mice. For example: When the amount of melatonin in the blood of aging mice was returned to its youthful level (melatonin production declines with age), they increased their expected lifespan 30 percent. In two more studies, melatonin seemed to shield mice from the effects of cancer-causing chemicals and radiation. In rats and mice, melatonin is a stimulant, waking them up. There's no data on humans yet and it's possible that results in humans may be different from or even opposite those in animals.
Should you take a chance, then, and buy a bottle of melatonin? No, according to Mayo specialists, for several reasons. First, caution is warranted because long-term effects of melatonin supplements are unknown. Also, melatonin is currently sold as a food supplement,
so its manufacture and marketing are not subject to the strict pharmaceutical standards of the Food and Drug Administration. Dangerous impurities may creep into the manufacturing process, as was the case with L-tryptophan, a chemically similar amino acid sold
over-the-counter a few years ago. Dozens of people died as a result of taking it, and hundreds were permanently harmed. |
