At the end of the 19th century, we began to get really interested in inheritance patterns. How and why did my first son get his blue eyes from me, while our daughter arrived with her mother’s green eyes?
This sort of phenomenon of inheritable characteristics occupied an army of
brilliant scientists for the entire 20th century (and beyond) and led to the science of “genetics”: the study of genes and DNA that make us who we are. If DNA is the library of information about us, gene are the individual books. All of these books are ‘how to manuals,’ how to build a liver, how to make blue eyes, etc., etc. You get the idea. Each time your body is challenged or needs to accomplish something, it grabs a specific “how to” gene and sets about building proteins to construct a product.
Like many others, I have spent my whole life fascinated and a bit enthralled
by the concept and promise of genetics. As a doctor, my hope for genetics
has been a cure for all the maladies that cause suffering and shorter lives.
After all, on some level, everything that your body does is a “genetic” issue:
growth, appearance, asthma, cardiovascular disease, autoimmune
issues… none of it happens without using genes to make it happen.
Genes as destiny?
A common misconception about genetics is that genes determine our destiny. For example, if cancer runs in your family and you have the same genes…uh oh. This is such an important myth to dispel. It is very
unempowering to buy into the idea of genes and only genes determine our
fate. They don’t. Have you ever heard of BRACA genes? Many have. These are genes that increase the risk of getting breast cancer. So, if your mother has breast cancer and has a BRACA gene, and you have the gene too, does this mean you will absolutely get breast cancer? Luckily, the answer is no. Genes mostly confer a change in risk (good or bad) of
something happening. There must be more going on here determining what
happens to us.
Epigenetics
Here’s an interesting fact. All your cells contain identical DNA and thus genes as well. A liver cell, a brain cell and a stomach cell all have identical sets of genetic information. And yet, they are all radically different types of cells, functioning in completely unique ways, producing unique types of
proteins and products. What gives? Each of these cell types are only accessing a small part of the DNA library. Your brain cells are only using
the genes that produce neurons and neurochemicals. And they have “shut
off” all the other genes that code for things like “how to make a liver cell”.
That’s not the cool part though! The cool (and useful ) part is how those
cells turn genes on or off.
If the 20th century was the era of genetics, then the 21st century is the era of epigenetics. Genes are a bit like light switches- they are on (being used to produce a product) or they are off- doing nothing. Epigenetics is the mechanism our cells use to flip the switch. How cool is that? What if you inherit a gene that increases your risk of cancer, but the gene is shut off? That’s as good as not having it right? Or, what if there was a way to influence your body to shut that gene off? Now you have the power to influence your health! Our understanding of epigenetics is giving us tremendous insights into how to leverage it for our own benefit.
The other stuff we inherit from our parents
We inherit our genes from our parents, that we knew. We also inherit epigenetic patterns too. When we are born, a lot of our genetic switches are pre-set to be similar to our parents. You could think of this as your default settings. Somewhat like the factory settings that came with your computer before you started to personalize it for your own use. You know what else we inherit from our families? Habits, lifestyles, ideologies, preferences, and biases. We learn how to operate by following the example of those around us. Why is that important? Epigenetics! Have you wondered yet, “what determines when and if to turn on or off a gene?” After all, what is the point of having on/off switches if you don’t need to turn things on or off sometimes?
Here it is, your cells are reacting to their environment in real time. How you live your life or what you put your body through: activities, stress, nutrition, job, hobbies, where you live, what’s in your environment… all of it has an impact on your cells, and they start adjusting gene switches to react to all of it. Those adjustments are all to maximize your function given what’s going on around you at this moment. Sometimes these adjustments lead to increased risk of long-term chronic problems and that’s how we end up with things like type 2 diabetes, coronary artery disease and sometimes cancers.
You are what you eat: A twin experiment.
The big picture is this: genes are not our destiny. What we do with our genes drives outcomes.
Want to learn more? On Netflix currently, there is a show titled: “You are what you eat: a twin experiment”. This documentary reviews a study involving 22 pairs of identical twins. They looked at each twin pairs baseline health and then put them on a different lifestyle plan: a work out plan coupled with a whole food plant based diet vs healthy omnivore diet. They followed their progress for 3 months and measured changes in things like: weight, muscle mass, body fat percentage, mental acuity, cholesterol, insulin resistance, blood flow.
What they found was this: genetically identical people will grow and change in very different ways based on the lifestyle they adopt. Have you ever wondered what your life would look like if you had done this instead of that? Took that job, not this one. Took this chance not that one? This study is like that. Each set of twins started the study basically in the same health, same degree of fitness, you could say, the same epigenetic set points! But as the study progressed, their health measures diverged from each other in surprising ways.
I won’t ruin the watch for you, so no spoilers here. But the message is clear. Everyone of us has the ability to change for the better or worse. By controlling what we let in or out of our lives, we are flipping the epigenetic switches that control the risks and rewards our body has to offer us. So, as we are diving into 2024, lets all look at the different facets of our lives and see if we can flip some of our epigenetic switches to a better lifelong health setting.
Good luck and let me know if you need me!