Speaker presentations
• Carl Eisdorfer, M.D., Ph.D., Knight professor and director, University of Miami Center on Aging | Presentation
• Matt Kaeberlein, Ph.D., assistant professor, Department of Pathology, University of Washington | Presentation
• George M. Martin, M.D., professor emeritus, Department of Pathology, University of Washington; adjunct professor of genome sciences (retired) and director emeritus of University of Washington Alzheimer’s Disease Research Center | Presentation
• Peter Rabinovitch, M.D., Ph.D., director, University of Washington Nathan Shock Center for Excellence in the Basic Biology of Aging | Presentation
By Laura Gater
Independent journalist
On Friday morning, AHCJ conference attendees learned that they have been aging since conception. Most of us have heard this before, but did not want to be reminded of it. Aging is a biological, psychological and social process, as four researchers explained at Health Journalism 2009.
Aging research is important to learn how to slow down the process. At age 50, humans have about 62 years left of their lives, according to Matt Kaeberlein, Ph.D., assistant professor, Department of Pathology, University of Washington (or we might if we learned how to slow down the aging process).
One of the biggest factor of aging is smoking, which affects reproduction, cardiovascular, pulmonary, skin, bone and neoplasia. Genes actually play the biggest role in lifespan. Kaeberlein noted that there is no reason that the human body has to wear out with time, and aging must be "programmed."
The effects of aging are the strongest later in life. He explored the cost of not aging, which included higher repair and maintenance (of our bodies) and a lower reproduction rate. Aging is not necessarily "programmed" into us, but rather, it is "controlled." People age differently, affected by both genetic and environmental factors.
Aging influences many body processes: hair loss, cancer, stroke, type 2 diabetes, wrinkling, arthritis, heart disease, and neurodegeneration (i.e., Alzheimer's).
"Slowing aging should slow the progression of many age-associated diseases," explained Kaeberlein.
The model organisms used in aging research are humans, worms, mice, and yeast. One sure thing that researchers have noted is that dietary restriction slows aging in yeast, worms, flies, mice, rats, spiders, fish, and proboscis monkeys, and it delays the onset of most age-associated disorders. It is not yet known if dietary restriction works to slow aging in humans, said Kaeberlein, but he thinks that there are some reasons to be optimistic.
At least 25 gene pairs overlap between yeast and worms, so if researchers target these "conserved aging" pathways in humans, they may be able to slow aging. Lifespan studies are ongoing.
Carl Eisdorfer, Ph.D., M.D., a Knight Professor and director of the University of Miami Center on Aging in Florida, listed the top disabling conditions in the United States. They are mental and emotional conditions (these are the most disabling conditions), arthritis and musculoskeletal conditions, cardiovascular disorders, stroke, respiratory diagnoses, and cancer. Eisdorfer pointed out that the stress response is toxic to the body because it kills cells. His rules for lifestyle are exercise, eating an adequate diet, having a positive attitude, and keeping track of one's medications.
Peter Rabinovitch, M.D., of the University of Washington, presented the Free Radical Theory of Aging, which is based on free radical and radiation chemistry. This is the most widely cited theory of aging, but it is yet unproven. The evidence from nature is mixed, and evidence from antioxidant over expression is variable. In both flies and rodents, said Rabinovitch, results appear to depend on genetic background and other generally unknown factors. Mitochondrial oxidative phosphorylative function has been shown to decline with age in human and primate tissues, including the brain, skeletal muscle and liver. Mitochondrial DNA mutations have been shown to accumulate with age in mammalian tissues, including the brain, heart, and skeletal muscle. The preserved organ function in aging may be a valuable marker of improved health span, and a more significant indicator than lifespan.
