Dr. Isabelle Mansuy

In this episode of Just Like Nana, host Amie (Elizabeth) Penny Sayler sits down with Dr. Isabelle Mansuy, a Professor in Neuroepigenetics. They get to the root of ancestral trauma, starting with the groundbreaking science of epigenetics and the transgenerational effects of trauma.

Dr. Isabelle Mansuy is a leading expert in the field of neuroepigenetics and a professor based in Switzerland. Her pioneering research focuses on the biological mechanisms of how traumatic life experiences, particularly those occurring in early childhood, modify mental and physical health across generations. Through her extensive work with mouse models, Dr. Mansuy has provided some of the most compelling evidence to date that traumatic signals can be carried in the germline (sperm cells), affecting the behavior and physiology of offspring up to five generations later.

Have you ever felt like you were carrying a weight that didn’t quite belong to you? Maybe you’ve struggled with chronic anxiety, persistent low moods, or even physical health issues that seem to have no clear origin in your own life story. For a long time, I’ve explored these questions through the lens of “ancestral trauma,” but I’ve always wanted to understand the hard science behind how the past stays alive in our bodies.

That quest led me to a fascinating conversation with Dr. Isabelle Mansuy, a world-renowned professor of neuroepigenetics in Switzerland. Her groundbreaking research is fundamentally changing how we view heredity, mental health, and the legacy we inherit from our ancestors.

One of the first things Isabelle highlighted was the use of the term “intergenerational trauma.” She pointed out that often the trauma itself (the event) isn’t what’s passed down. Instead, it’s the biological consequences of that trauma.

“If you have a transgenerational trauma, it means the trauma itself is reiterated at each generation,” she explained. In reality, your grandfather might have experienced the traumatic event, but you—the grandchild—inherit the depression, the antisocial behavior, or the metabolic issues that resulted from his experience. Her perspective shifts the focus from “reliving the past” to treating a biological reality in the present.

I asked Isabelle to help us understand how these consequences get passed down, and she gave me an analogy to computer technology.

• The Genome (Hardware): This is your DNA sequence—the fixed code.
• The Epigenome (Software): These are the chemical “marks” that sit on top of your DNA. Just as a computer needs software to tell the hardware what to do, your body uses epigenetic marks to tell your genes when to turn on or off.

Unlike your DNA, which is fixed, your epigenome is dynamic and reversible. It changes based on what you eat, how you move, and the stress and emotions you experience. Isabelle’s work shows that these changes can be passed down several generations.

Isabelle’s lab uses mouse models to study trauma. They look at “unpredictable maternal separation” (which creates childhood trauma for the mouse pups), and the results are staggering.

The stressed pups grow up to exhibit depression, memory loss, and high-risk behaviors. But here is the kicker: when these traumatized males have offspring, their children—and even their great-great-great-grandchildren—show those same symptoms, even if they lived perfectly peaceful lives.

I was particularly struck by her findings on the father’s role. For a long time, science assumed fathers only contributed DNA. Isabelle proved that sperm also carry “epigenetic luggage,” RNA and other signals that inform the embryo about the father’s life experiences. Even using IVF with a traumatized male’s sperm produced offspring with trauma symptoms. It’s a powerful reminder that our biological history is more than just a sequence of letters.

One of the most surprising parts of our talk was learning that ancestral trauma doesn’t just affect our moods; it affects our hearts. Isabelle’s lab found that the descendants of traumatized mice often suffered from heart failure, despite having healthy diets and active lives.

This has massive implications for how we view medicine. Imagine a world where a cardiologist looks at your family history of stress, not just your cholesterol, to understand your heart health. It changes the entire approach to diagnostics.

The most healing part of my conversation with Isabelle was her perspective on shame. In our culture, depression is often seen as a personal failure.

“If you consider that depression may come from your parents or even your grandparents, just like you inherited the shape of your nose… that can really help people understand,” she told me. When we view mental health as a biological trait we’ve inherited, the guilt disappears. It isn’t a character flaw; it’s history.

Isabelle’s research is a call to compassion. While we cannot change the “hardware” we were born with, the “software” of our lives is dynamic. By understanding the biological signals we carry, we can seek the right support, break the cycle for our children, and move forward with a deeper understanding of who we are.

Website: https://www.mansuylab.ch/team/isabellemansuy

Are you curious about the “Elizabeths” in your own family tree? We want to hear from you!

• Website: justlikenana.com
• Share Your Story: If you have a family story or trauma you’re exploring, reach out via our website for a chance to be interviewed.