I have fraternal twins, so I got to watch firsthand how genetics can shape a kid. My boy is night-and-day different from his sister and he always has been, despite our best efforts to raise them the same. However, others would argue that environment often trumps genetics. So which is it?
Genetics vs. Environment
Genetics is a complex field of study that investigates life at the level of cellular DNA, or our genes. We inherit our unique genetic makeup from our parents, and as such, we have two copies of each gene, one from our mom and one from our dad. Our genes determine the basic things, like eye and skin color, the shape of our ears, whether we have curly or straight hair, and so on, but they can also carry inheritable codes for diseases, such as autism, dementia, and certain cancers. Research has also shown that things such as IQ and happiness can be inherited through our genes. So we come preloaded, so to speak, with a blueprint for life.
Environment, on the other hand, is simply the ability of the world around us to alter who we are. For example, you may not be genetically prone to obesity; however, if you live on a diet of fast food and doughnuts, the ensuing obesity is certainly a product of your environment. You may not carry a gene for lung cancer, but if you smoke, you have a very high risk for lung cancer due to the environmental exposure to the carcinogens in cigarette smoke.
So while it seems obvious that we can be a product of either genetics or our environment, a new question researchers set out to answer is whether the environment can alter our genetic structure, making us a true product of both. In other words, does environmental influence change our genetic blueprint? This is such a hot topic, by the way, there’s a whole field of study dedicated to it called epigenetics, meaning how our genes may be altered by the environment. Let’s take a look at the study.
Epigenetics: Environmental Influence Can Change Gene Expression
The new study looked at how cells in the cerebral cortex of mice respond to a specific sensation (in this case light). After subjecting the mice to total darkness, the mice were then exposed to light while researchers analyzed thousands of cells and gene types. Of over 114,000 cells examined, just a single burst of the light dramatically altered expression in over 600 genes, suggesting we don’t just learn from environmental influence but our genes can actually be altered by the outside world.
The researchers concluded that humans can’t be so neatly narrowed down to being a product of either genetics or environment; based on how genes respond to environmental stimuli, the study suggests we are actually a product of both.
More Interesting Findings on Genetics and Our Environment
Studies on how our environment affects our genes (epigenetics) have also made some interesting findings in recent years. For example, a recent study found that aging can be genetically altered by exercise. Joint replacements fall under the category of environmental influence because they are devices introduced into the body that aren’t supposed to be there. A couple of studies have found that the wear particles from these joint replacements can alter genes by causing genetic instabilities and abnormalities. This new study of how genes can be altered by the environment gets really freaky when you consider that these changes can be passed down to your kids!
How does the environment impact your stem cells? A recent study demonstrated that alcohol can damage the DNA in stem cells. This is critical as stem cell genetic damage has been associated with being sicker and an early death.
The upshot? Your genes can be altered by your environment. This includes your stem cells! Hence, get loads of exercise, lift heavy weights, drink tea, avoid drinking a lot of alcohol, and avoid stuff that will mess up your genes!