"Aging" has become the new buzzword in town. It is hard to get through one day without hearing about 'healthy aging'; reversing 'aging'; embracing 'aging'; 'anti-aging' creams, lotions and tonics. In a society that is obsessed with turning back the clock, there are huge benefits to knowing the facts about the aging process. By learning what causes it, maybe we can prevent and outsmart it. Here is a first instalment on what underlies this mystifying process - based on a workshop in Victoria BC.
The Greater Victoria Eldercare Foundation sponsored many special events, activities and workshops during their March initiative called "Embrace Aging Month." On March 13, attendees were treated to a fascinating talk by Dr. Edward Ishiguro, Department of Biochemistry & Microbiology at the University of Victoria, on "The Biology of Human Aging." Dr. Ishiguro started his talk with the good news that, in Canada, we enjoy one of the longest life expectancies in the world – one that has been increasing steadily since the early 1900s.
The UVic Professor Emeritus talked about Dr. Leonard Hayflick, whose momentous work provided answers about the process of aging in human cells. The "Hayflick Limit" refers to his discovery that there is a definite limit to how much a human cell can reproduce itself – the number is 50-60 duplications. Essentially, a cell dies when it can no longer replicate itself. Dr. Hayflick called this process "Replicative Senescence" and he theorized that this was due to the progressive accumulation of damage to the cell from various sources. When people are young, these senescent cells are effectively removed by the immune system and replaced with new healthy ones. But as we age, our immune system becomes less efficient at getting rid of these non-functional cells. According to Dr. Ishiguro, the accumulation of these senescent cells in the body over a life span can lead to chronic disease and induce a limit on how long we live.
We were all startled by a quote in Dr. Ishiguro's slideshow: "Oxygen is the ultimate toxin...The biochemical price of breathing is aging." The explanation alludes to "The Free Radical Theory of Aging." Per "www.rice.edu/~jenky/sports/antiox.html", free radicals are "groups of atoms which can be formed when oxygen interacts with certain molecules...The chief danger comes from the damage free radicals can do when they react with important cellular components. Cells may function poorly or die if this occurs." Dr. Ishiguro believes that senescence begins with the accumulation of this damage by free radicals.
To prevent free radical damage the body has a defence system of "antioxidants", molecules that neutralize the villains. However, the principle micronutrient (vitamin) antioxidants are supplied by the diet. Dr. Ushiguro feels that the most effective "way out" of this vicious aging cycle is through regular exercise and a nutritious calorie-restricted diet. Exercise increases aerobic capacity, resistance to fatigue and endurance and a diet high in nutrients and low in empty calories builds health. Another big pay-off is that they both decrease free radical-induced damage, thus giving our bodies a fighting chance at a long healthy life.
The entertaining scientist left us with some inspiring words: "Aging is not a disease: it is a natural, universal process. Embrace it!" His advice for aging well: "Be happy, don't abuse your diet, and stay physically and mentally active."