THE SCIENCE OF GETTING OLD
Nobody lives forever. In fact, if you're over 20 years old, it's likely you're already experiencing the effects of age on your body (they are probably slight if you're that young). Aging is an inevitable part of life, but do you know the science behind why hair becomes gray or skin wrinkles as we age?
Why Do We Age?
Eventually, the cells in our bodies become less equipped to repair and replicate themselves. This process of senescence is the basis of aging.
Scientists believe senescence is an irreversible step in the lives of cells, but what's not known is why this happens in the first place. One theory is that senescence of cells developed to prevent the uncontrollable growth of cells in old age; we know this as cancer.
Interestingly, some research suggests there may be ways to extend the lifespan of cells by using an enzyme in the body called telomerase. In the cell-division process, telomeres keep DNA and RNA from becoming damaged.
Eventually even the telomeres can no longer divide, meaning the cells become susceptible to age and death. But in some cells, including those in your immune system, telomerase restores the telomeres to their full size after cell division. These cells are said to be immortal, and they make up only a tiny portion of the cells in a human body.
For unknown reasons, the mortal cells in your body do not allow telomerase inside. Two separate research projects aim to use telomerase to rapidly expand human lifespans.
Curing cancer?
Four clinical trials are currently under way denying telomerase to areas of the body where cancer is growing. If successful, the cancer cells would not be able to multiply, and the existing cancer cells would die.
Endless youth?
Researchers have forced mortal cells to accept telomerase; the senescent cells saw their biological clocks reset and starting dividing again.
Why Hair Turns Gray
Melanin, the pigment that gives your hair its color, becomes exhausted at some point, which is different for each person. Genetics and stress both play huge roles.
Why Skin Wrinkles
Collagen is what gives youthful skin its luster and supple feeling. Starting when you turn 20, your body produces about 1 percent less collagen every year. The cumulative effect after a number of years is that the skin becomes thinner and more fragile, thus more susceptible to the ravages of gravity.
In 2007, 174,290 collagen injections were performed to fill wrinkles.
Why We Forget
Minor declines in memory and mental abilities most likely occur because the brain, like many parts of the body, changes as we age. Certain parts of the brain shrink, and the ability of neurons to communicate effectively with each other declines.
Why We Get Shorter
The disks between the bones in our spines become compressed over time. This causes the vertebrae to press closer together, meaning we lose height. Some elderly people also suffer from osteoporosis, a process in which insufficient bone material is created by cells in the body, and bones become smaller and weaker as a result.
55% of the opulation 50+ has osteoporosis or low bone mass.
Each hip fracture due to osteoporosis accounts for $40,000 in total medical costs.
Why We Can't See As Well
After age 40, most of us will have a hard time focusing on objects up close. You can thank the hardening of the surface of your eye's lens.
1 in 2 Americans 80 and older have cataracts that detract from their vision.
SOURCES
- http://www.huffingtonpost.com
- http://www.lbl.gov
- http://gizmodo.com
- http://www.loc.gov
- http://www.scientificamerican.com
- http://www.yourplasticsurgeryguide.com
- http://www.nia.nih.gov
- http://www.osteometer.com
- http://www.allaboutvision.com
- http://www.statisticbrain.com
