CARVILLE: Science of aging |

CARVILLE: Science of aging

Ever wonder why we age?

Why some people age better than others?

The science of aging is not completely understood, but it is clear that there are both internal and external factors which influence the aging process. Let’s look at both.

Internal Factors

Your body grows and repairs itself through cell division. Cell division is necessary for growing new skin, blood, bone and other cells.

There are trillions of cells in your body constantly dividing and making copies of your DNA. Each time a cell divides it makes copies of its chromosomes so both new cells have identical genetic material.

To protect each cell during this division process there are protective tips called telomeres at the end of each chromosome. You can think of telomeres as analogous to the plastic tips on your shoelaces — they keep chromosome ends from fraying and sticking together. With each division the telomeres get progressively shorter. When the telomeres become too short, the cells can no longer safely divide. They become senescent or die.

The ‘aging issue’ here is that there is a limit on the number of times the cells will divide. It’s called the Hayflick Limit. In humans this limit is usually 50 to 70 times – the average human Hayflick Limit is 52 divisions.

Telomeres have been compared to bomb fuses. Each shortening is associated with aging and a higher risk of cancer and death. Since cell division is universal in all living things, one could say that all life is pre-programmed to die. It is a natural process.

We all have the same fate… it’s part of the wisdom of life. For those of you who are watching the Ken Burns “Country Music” series on PBS, you may have heard Hank Williams sing his classic “I’ll Never Get Out of This World Alive.” I am listening to his song as I write this paragraph. Hank has been called the Shakespeare of Country Music. Thanks, Hank. I understand.

So, a major internal factor is how your telomeres shorten. What are some of the External Factors?

External Factors

There have been many aging studies conducted on identical twins. Because these twins are identical genetically, any differences are assumed to result from external factors. As you can guess, the differences can be dramatic.

Your environmental and lifestyle choices greatly influence the aging process. For example, sun-exposure (ultraviolet radiation) and smoking greatly influence visible skin conditions. ‘Elastosis’ is the presence of wrinkles, furrows, crow’s feet, baggy eyelids, etc. ‘Telangiectasia’ is the presence of uneven skin coloring: greyish, yellow with prominent blood vessels.

Other major external factors are the ones you already know – alcohol consumption, stress, diet, exercise, disease and medication. The mantra “Diet and Exercise” should be your guide. Drink moderately, eat sensibly, make sure you exercise and maintain a positive outlook on life.

The positive outlook means ‘be social,’ invest in personal relationships, acquire new skills, resist negative thoughts, volunteer. ‘Aging’ is just the amount of time we have on earth to do good things.


In summary, the genetic effects on physical ageing may be highly overrated. Lifestyle choices are more important and are the factors which you can control. Don’t worry about being ‘preprogrammed to die.’ Program yourself to live.

So, here is my simple ‘anti-aging’ advice…pretty easy to remember: Don’t eat like a pig, Don’t drink like a fish. Don’t move like a snail. Don’t smoke like Kate Moss.

Phil Carville is a co-owner of the South Yuba Club. He is happy to respond to questions or comments. He can be reached at

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