Flipping the Genetic Switch: Epigenetic Factors
The more you look at epigenetics, the more it seems that our lives are little more than a checklist of various genes that can be turned on or off. Don't want to age as fast? Click here. Care for a little obesity? Just mark "yes" or "no" with a No. 2 pencil. Of course, the kicker is that we're still trying to figure out what factors lead to which answers on the genetic Scantron sheets that define our lives.
Epigenetic changes, like so many of our vital processes, fall to our bodies to deal with. Just think back to the last time you burned dinner or wore the wrong socks to work. Do you really want direct control over your heartbeat or how your genes are expressed? No, so your body responds to your environment and takes care of all this for you. Meanwhile, your brain (which is to say, you) gets to concern itself with such essential problem-solving tasks as gathering food, breeding and remembering to turn off the iron. In our free time, however, we've devoted a great deal of effort to figuring out just how our bodies do what they do. As such, we've already figured out how some factors cause epigenetic changes.
Nutrition: As the saying goes, you are what you eat. Research has shown that shortages or excesses of food during a person's childhood can cause epigenetic changes that lead to diabetes, obesity and early puberty. Adaptations that made sense during a time of famine can then transfer to children and grandchildren who live in a time of plenty. Genes become epigenetically set to deal with adverse conditions and then pass on to offspring who may enjoy comfier conditions. Experiments have also shown how foods can cause epigenetic changes in the womb. Scientists have influenced coat colors and deterred obesity in mice by feeding the mother a soy-rich diet, which alters methylation [source: Ray].
Parenting: The field of epigenetics continues to shed light on the importance of parental care to mental health. Experiments have discovered that mother rats that infrequently groom and nurse their pups rear anxious offspring. This poor parenting actually alters genes controlling the production of stress hormones. This is nature's way of preparing young for a potentially dangerous environment. In humans, scientists have observed methylation changes in the brains of suicide victims. Areas of the hippocampus, a part of the brain that can affect mood, contained genes that had been switched off. An estimated one out of every five suicide victims suffered child abuse, leading experts to consider a possible correlation between stressful upbringings and epigenetic change [source: Economist].
Research continues to uncover connections between epigenetic change and various factors in our environments and diets. How can we benefit from this knowledge? Find out on the next page.