Studying this in humans is really, really difficult. There are too many variables and it takes too long to get data about life expectancy. Worms, on the other hand, are great for this type of study -- specifically a tiny worm called a nematode (you may have dissected these in high school biology class). Nematodes are an amazing research subject for aging and genetics studies because they don't live very long (you don't have to wait a long time for results) and their genome (genetic code) is mapped and not overwhelmingly big.
Chronological Aging and Physiological Aging
In aging research, two types of aging are studied: chronological age (the amount of time an organism has lived) and physiological age (how healthy you are). For example, a man can be age 70, but his body may be more like that of a 50-year-old (known as successful aging). Or, he may be 70 and his body functions more like a 90-year-old (poor aging). Trying to figure out the physiological age of people is a multi-million dollar business (see RealAge). Trying to figure out the physiological age of nematodes is simply research.Genetics and Aging in Nematodes
To test aging in worms, the researchers put the nematodes in dangerous situations that cause the worms to react. The scientists then measured their speed, dexterity, etc. Over time, a database was built that showed the average and extreme reactions of elderly nematodes. Next, researchers took all the data and looked into the DNA and genetics of the nematodes. Looking at genetic information alone, they could predict, with 70% accuracy, the difference between the nematode's chronological age and physiological age.So Am I Doomed By My Genes?
No. It is was more complicated than that. Nematodes are pretty simple organisms and they all grew up in very controlled environments in the lab. The analogy for people would be to take people and keep them all in the same house, feed them the same food and give them the same amount of activity over their entire lives. Some of them will age well and others will not and we could determine who had the best genes for that environment. But we live in a world with lots of change and variation. Some people may have a gene for high cholesterol that leads to heart problems only if exposed to a poor diet (but if they were a strict vegetarian, this gene would not be a problem). So the key is to understand the genetic factors and adjust/optimize your lifestyle to minimize risk. We aren't there yet, but expect more genetic health information to come out that impacts aging. Be prepared to make adjustments to your life to accommodate a bad gene here and there. And don't get too caught up in all this genetics and aging talk. You and I both know what we need to do to be healthier: eat right, exercise, de-stress, have more fun and sleep better. These things we can change, our genetics we can't.Source(s): Melov S. Aging Cell. November 20, 2008.
