The Myth Behind ‘It’s in my genes’

“But it’s in my genes!” This is a phrase I hear often in my clinic; patients come in worried that they are destined to get the type 2 diabetes their mom has, or the heart disease their dad has. At times they feel powerless against the impenetrable force of genetics. But are they right? And what does science say about this?

It turns out that we’ve got way more control over our genetics than most of us thought; in fact, it’s a whole new field of science with a fancy name — epigenetics.  Let’s get into some of the common myths about genetics:

We’ve got our genes, coded into our DNA, which is wrapped up in a tight ball. These are known as our chromosomes, which we got from mom and dad. Our genes dictate everything from our hair color to our eye color.

Our body’s library of DNA is huge, and not all genes are turned on at the same time. This is important, because we have the same copy of DNA in every single cell in our body. If that’s the case, how does a fingernail cell “know” to become a fingernail? How does a heart cell “know” to become a heart cell—if all the DNA is the same? Yep, only some genes are turned on in any given cell, the others are turned off. This act of turning on and off genes — that’s what is being studied in epigenetics.

Some diseases are inherently genetic. If you’ve got the genes for it, you’ve got the disease, such as Cystic Fibrosis, Huntington’s disease, and Hemophilia. There’s not much that can be done in these cases for reversing it altogether; there’s no myth behind “it’s in my genes” in these cases.

But what about other diseases, like obesity, heart disease, high cholesterol and triglycerides, type 2 diabetes, and high blood pressure? In these cases, there may be a predisposition to the disease that was inherited genetically, but lifestyle choices ultimately decide your fate.

So the (somewhat morbid) saying goes, “Genetics loads the gun, but lifestyle pulls the trigger.” There is immense hope here: What you eat, how you exercise, and how you manage the stressors in your life dictates preventing or creating these diseases more than your genes do. It’s up to you! You can beat back diabetes, heart disease, and a whole host of other diseases by eating a whole-foods diet, walking 30 minutes most days, and practicing stress management techniques. It’s up to us, whether these genes for disease get turned on or off.

Still not convinced? Everyone in your immediate family is overweight and you’re sure you’re going to be? These trends in families usually happen because of the environment—families usually eat the same things, exercise (or don’t) about the same amount. The environment is turning the genes on—here, it’s lifestyle that matters most.

Courage, my friends, our health depends on the choices we make. You are more powerful than you might think.

Sources: National Institutes of Health 1, National Institutes of Health 2, Nature.com