Since researchers cracked the human genome some 10 years ago, we’ve had a heightened awareness of the importance of genetics in our risk for certain diseases and disorders, both mental and physical. Subsequent studies have continued to find connections between our genetic profiles and our likelihood of developing health problems, from breast cancer and heart attack to depression, obesity, and Alzheimer’s disease. Some people choose to undergo genetic tests to determine whether they carry copies of specific genes that put them at higher risk for various diseases. Knowing that one possesses copies of “cancer genes,” for example, can lead to some tough decisions about where to go from there.
Our genes are modified by the choices we make every day – the foods we put in our bodies, the chemicals we are exposed to, how active we opt to be, and even our social environments.
A bright spot, however, is that what’s also become clear in recent years is that genetics is only half of the discussion. Our lifestyles, as doctors are keen on telling us, are important in increasing or reducing our risk of various diseases. Research in the new field of epigenetics is finding that our lifestyle choices – the foods we put in our bodies, the chemicals we are exposed to, how active we opt to be, even our social environments – can actually alter our health at the level of the gene. These choices can have big effects on our risk for disease, even if our genes seem to be working against us. So before throwing your hands up and saying, “What can I do? It’s all up to my genes,” read on.
But what’s found to be equally true is that the positive lifestyle choices we make – most notably, eating right and exercising – may have just as powerful an effect on our genetic makeup. Two recent studies illustrate this point. One found that eating well can “turn off” the genes that put one at higher risk for heart problems1; the other showed that exercise can persuade stem cells to become bone and blood cells rather than fat cells. Each helps us see just how lifestyle variables work at the genetic level to modify our risk.
The study illustrates vividly how eating well will not only help you feel better in an immediate way, but it could actually alter your genes and reduce risk to your heart in a long term way.
Exercise is the other piece of advice that we hear over again. It is strongly linked to a variety of health benefits from heart and vascular health, to warding off Alzheimer’s, to extending lifespan. But now researchers are beginning to show that exercise may function, at least in part, by affecting the expression of our genes.
'Some of the impact of exercise is comparable to what we see with pharmaceutical intervention.'
Certain types of stem cells can "choose" how they differentiate, and exercise and environmental factors can actually determine the direction that cells take early in their development. When mice run on a treadmill for as little as an hour three times a week, the exercise induced these stem cells to become blood-producing cells of the bone marrow, rather than fat cells.
If exercise can influence how stem cells differentiate into mature cells, it is certainly possible that exercise also works on the genetic level as it influences our risk for certain diseases. More research will be needed to map out the molecular changes that exercise brings about. Again, since the evidence is overwhelming that exercise does reduce our risk for physical and mental health problems, it certainly won’t hurt to put on your walking shoes and get moving.
Much more work needs to be done to untangle the specific changes that are occurring in the genes exposed to different environments and lifestyles. Researchers do know that it’s not the genes themselves that are changed by lifestyle or environmental factors; rather, it’s likely the molecules around them, which can affect how active genes are.
We are not completely at the mercy of our genes. In many ways, they are at the mercy of our health and lifestyle decisions and habits.
Methylation is one example of the molecular changes that may occur in response to environmental factors, and there are other regulatory molecules that could certainly be affected by the foods we eat, the chemicals we come into contact with every day, the viruses we contract, and our level of activity. The addition or subtraction of a methyl group is known to be a cue for whether genes are turned off or on.
That our lifestyles can affect our genes in significant way is both sobering and encouraging. On one hand, our genes affect our health, since they can put us at varying levels of risk for health issues like heart disease, weight gain, and even depression. And on the other, our lifestyles also affect our health in significant ways at the level of the gene. Eating fruits and vegetables can “turn off” the heart attack genes, and exercise can sway the development of stem cells.
We are not completely at the mercy of our genes. In many ways, they are at the mercy of our health and lifestyle decisions and habits. Family history can be a strong predictor of disease, but we have at least some power to change it. Making healthy lifestyle choices may not be foolproof, but for many it could mean the difference between experiencing a significant health issue and avoiding it. So, your doctor’s advice is not just rote recitation. Pay attention to it with the knowledge that your genes are paying attention, too.