What is Epigenetics?

 

What if your grandmother’s childhood trauma could affect your risk of depression?

For decades, we believed DNA was a fixed script, but science is now revealing a second layer of inheritance: one that responds to life itself!

What is Epigenetics?

Epigenetics studies the changes in gene expressions that occur without altering the DNA sequence. In other words, how your environment, experiences, and even your emotions can affect the way your genes work without changing the actual DNA sequence.

Think of your DNA as a library. The books are your genes. Little “sticky notes” say things like “read this often,” “skip this chapter,” or “only open during emergencies.” Those sticky notes are epigenetic marks that control which genes turn on or off, and when.

So, what changes these “notes”?

Everything you go through in life (what you eat, the air you breathe, how much you sleep, whether you're stressed, loved, or neglected) can add or remove these marks. That means:

• Identical twins (with the same DNA) can end up very different.
• A person’s childhood stress or exposure to pollution might affect their health decades later.
• These changes can sometimes be passed to the next generation.

Real-World Evidence

1. The Dutch Hunger Winter (1944–1945)

During World War II, famine struck the Netherlands. Pregnant women had to survive on very few calories and gave birth to babies who looked healthy. However, decades later, these children had higher rates of obesity, diabetes, and heart disease.

Why? Their bodies had been epigenetically “programmed” in the womb to survive scarcity. When food became abundant later, their metabolism couldn’t adapt.

2. Holocaust Survivors and Their Children

Researchers found that children of Holocaust survivors had lower levels of cortisol, the hormone that helps regulate stress. These children didn’t experience the trauma firsthand, but their stress response systems were different—likely due to epigenetic changes passed down from their parents.

3. Rats, Motherhood, and Nurturing

In one study, baby rats raised by affectionate mothers grew up calm and resilient. Those raised by neglectful mothers were more anxious. When babies were swapped, their behavior changed to match the mothering they received. The nurturing they experienced changed their brain chemistry through epigenetic marks.

Try It Yourself: A Simple Experiment

One of the coolest things about epigenetics is that you don’t need a lab to understand it. Here’s a fun experiment with plants.

You will need:

• 2 small plants (beans, herbs, or grass)
• Sunlight or a lamp
• Water

Steps:

1. Place Plant A in a sunny spot and water it regularly.
2. Place Plant B in a shadier spot and water it less often (but don’t let it completely dry out).
3. Observe them over the next few weeks.

What happens?

Even though both plants started with the same genetic instructions, they’ll look and grow differently because of their environments. This is a perfect model of epigenetics: your DNA is like the seed, but how it expresses itself depends on the environment.

Note: Human epigenetics is complex, and while simple models help illustrate concepts, real biological mechanisms involve many interacting factors.