The genetics of aging is the study of inherited traits associated with aging. Lifespan, rate of aging, and age at onset of certain diseases (Alzheimer's, prostate cancer, osteoporosis) are some of the markers scientists use to research how your genetic makeup affects your aging process. Everyone has a unique combination of genetic information and environmental factors, and it is the interplay between the two that determines the rate of each person's individual aging process.
Genes are segments of DNA that contain the information necessary to build a living organism. Everyone inherits genes from their parents. Depending on which alleles, or forms of the gene, you inherit, you will express certain physical traits of the dominant allele in each gene. For example, if you inherit the allele for tongue rolling from your mother (dominant trait), and the allele for non-tongue rolling from your father (recessive trait), the dominant trait is expressed and you will be able to roll your tongue. In much the same way, you inherit genes from your parents that can partially determine how fast you age, how long you live, and what diseases you will be susceptible to later in life.
Many scientists now believe that errors in cell division are primarily responsible for the aging process. As cells divide over and over again, the telomeres, or sequences of DNA that cap the end of chromosomes (strands of DNA), become shorter and shorter. Eventually, they become so short that the cell is unable to divide or repair itself. These and other errors in cell division lead to altered gene expression, which then leads to loss of tissue function and aging.
Researchers are on the search for genes associated with late-onset diseases, and have isolated genes and gene mutations that are related to Alzheimer's disease, arthritis, prostate cancer, and osteoporosis. However, having these genes or gene mutations does not mean you are destined to get the disease. Genes determine what may be expressed in an organism, but interaction with their environment is the ultimate test; different environments can produce different features in the same genes. The bottom line is that while genes can indicate an increased risk for disease, environment and lifestyle play an important role in your health and the aging process.
Animal studies provide an interesting look into the aging process. Scientists discovered an altered gene in fruit flies that doubled their life span; with a similar DNA sequence to humans, studies of fly genes provide insight into how humans age. Scientists also found a gene mutation in roundworms that correlated with a lifespan of up to three times longer than normal! And, in another study, mice on a calorie-restricted diet had an increased lifespan; some studies confirm that this effect transfers to humans, as long as the diet is high in nutrition.
You can't control your genes, and at least for now, altering your genes to change aging patterns (as in the fruit fly study) is a distant reality. Besides, only about 35 percent of your lifespan is indicated by your genes. That leaves 65 percent that is in your control! Work on these diet and lifestyle changes to stay young and prevent many common ailments.
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