How Life Gets Under the Skin
Epigenetics, Telomeres, and the Biology of How We Live
“Take care of your body. It’s the only place you have to live.”
During the winter of 1944 - 1945, near the end of World War II, people living in the western Netherlands experienced a devastating famine.
Food supplies had been severely restricted. Daily rations fell dramatically, and people ate whatever they could find. Thousands died from starvation and its consequences.
Among those living through what became known as the Dutch Hunger Winter were pregnant women. Their children survived, and decades passed.
Then scientists began asking an extraordinary question: could an experience that happened before these children were even born still be detectable in their biology many decades later?
Researchers studied people who had been exposed to the famine around the time they were conceived and compared them with siblings who had not experienced the same prenatal conditions.
More than sixty years later, they found differences in a chemical marking of DNA associated with a gene involved in growth and development. The DNA sequence itself had remained the same, while something about how that genetic information was regulated was different.
The environment these developing human beings encountered so early in life had left a biological trace that scientists could still detect six decades later.
That discovery gives us a remarkable way to begin thinking about our own lives.
We inherit our biology. Then our biology lives our life with us.
Why does knowing this matter? Because understanding what happens inside our bodies can change the way we live outside them. Most of us already know that sleep, movement, food, stress, and recovery matter. Science helps us understand why they matter in ways we cannot see.
Once we understand that the conditions in which we live become part of the conditions in which our bodies function, ordinary choices begin to look different.
The Same DNA, Different Possibilities
Most of us grew up with a fairly simple understanding of genes. We inherit DNA from our parents, and that DNA contains genetic information that helps shape everything from eye color to aspects of our health. We receive the genetic hand we are dealt, and we live with it.
There is another layer to the story.
Nearly every cell in our body contains essentially the same DNA, yet a cell in the heart behaves very differently from a cell in the skin or brain. Part of the answer involves epigenetics.
Epigenetics refers to mechanisms that help regulate how genetic information is used without changing the underlying DNA sequence itself.
One way to imagine it is to think of DNA as an enormous book of biological instructions. Having the book does not mean that every page is being read at the same time. Different cells use different parts of the information, and biological mechanisms help regulate what is available to be read and how genes are expressed.
Some of these regulatory processes respond to conditions inside and outside the body. Nutrition, environmental exposures, physical activity, sleep, stress, and age all participate in the biological environment in which our bodies function.
Our biology is dynamic. The relationship between life and gene regulation is complex, and the useful idea for us is simple: what we inherit matters, and what our biology encounters during life matters too.
Life Leaves Marks
The Dutch Hunger Winter is such a powerful example because the exposure was extreme and historically documented. It allows us to see something that is much harder to recognize in ordinary life.
Our bodies are constantly responding to the environments in which they live. Some of those environments arrive with us through circumstances, history, exposures, and chance. Others are shaped, at least partly, by patterns we repeat.
What we eat, how much we move, how we sleep, whether we smoke, and how often our bodies function under sustained stress without adequate recovery all become part of the conditions in which our bodies have to function.
Human biology remains far too complex for any one behavior to guarantee a particular outcome. Still, once we understand that our repeated patterns become part of our biological environment, many ordinary choices begin to look less ordinary.
The Protective Ends of Our Chromosomes
Another area of science gives us a different window into the relationship between how we live and how our bodies age.
At the ends of our chromosomes are structures called telomeres. They are often compared with the protective tips at the ends of shoelaces because they help protect chromosome ends from deterioration and from being mistaken for broken DNA.
In many of our cells, telomeres generally become shorter as cells divide and as we age. Their biology is complex, and telomere length is influenced by many factors, including genetics.
The discoveries that revealed how telomeres protect chromosomes earned Elizabeth Blackburn, Carol Greider, and Jack Szostak the 2009 Nobel Prize in Physiology or Medicine.
Blackburn later began collaborating with health psychologist Elissa Epel. I find that collaboration particularly interesting. One scientist had spent years studying what happens at the ends of chromosomes; the other studied stress and human behavior. Cell biology met lived experience.
In one of their landmark studies, researchers examined women who were mothers of either healthy children or children with chronic illnesses. Caring for a chronically ill child can create sustained psychological and physical demands over many years. Greater exposure to caregiving stress and greater perceived stress were associated with aspects of telomere biology, including shorter telomeres.
Blackburn and Epel later brought this work to a broader audience in the book The Telomere Effect, exploring what telomere science can teach us about aging, health, stress, and the way we live.
Telomeres are influenced by many factors, and research across different populations has produced a complex picture. The larger value of the work is the window it gives us into a profound connection: what happens in a human life and what happens in a human body belong to the same story.
When Stress Becomes a Way of Living
Stress is part of being alive. Our stress response helps us meet challenges by mobilizing energy and preparing us to respond when something requires attention. The body also needs opportunities to recover.
An intense day followed by rest is very different from living for months or years in a state of constant pressure, poor sleep, little movement, inadequate nourishment, and almost no recovery.
Many people become so accustomed to living under pressure that stress stops feeling unusual. It simply feels like life.
We wake up tired and keep going, eat while working, carry unfinished conversations into bed, sleep with our phones beside us, schedule every available hour, and wonder why we feel depleted.
The body continues living inside those choices.
Understanding the biology invites us to notice the conditions we repeatedly ask our bodies to inhabit. That is awareness.
What Does Knowing This Change?
Science becomes useful in our lives when understanding changes the way we see something.
Most of us already know that sleep is important, movement is good for us, nutritious food matters, smoking damages health, and relentless stress is difficult for the body.
Epigenetics and telomere research give those familiar ideas another dimension. Our daily lives create biological conditions.
A walk is still a walk. A good night’s sleep is still a good night’s sleep. A meal rich in nourishing foods is still dinner. An evening spent recovering rather than continuing to work is still an evening.
Each choice is small. Repeated over time, our patterns become part of the environment in which our cells, organs, nervous system, immune system, and brain function day after day.
That understanding can change the meaning of taking care of ourselves. It becomes a relationship with the body carrying us through our life rather than a list of things we are supposed to do.
Agency Without Blame
There is an important responsibility that comes with talking about this science. Human health emerges from many interacting influences: genes, environment, access to health care, social and economic circumstances, infections, accidents, exposures, developmental experiences, behavior, and chance.
A person can exercise, eat well, sleep carefully, manage stress, and still become seriously ill. Another person can ignore nearly every health recommendation and live to an advanced age.
Awareness gives us agency over the parts of our lives we can influence while leaving room for the complexity and uncertainty that belong to biology.
I find that distinction freeing. Perfect control is unnecessary for our choices to matter.
The Biology of How We Live
When we design our life, we naturally think about what we want from it: where we want to live, the work we want to do, the people we want around us, the experiences we want to have, and what we want the next chapter to become.
There is another dimension worth considering: the environment we are creating for the body that has to live this life.
A calendar can look beautifully productive while the person living inside it is exhausted. A career can look enormously successful while the body carrying that success has forgotten what recovery feels like. A life can be full of experiences while leaving little room for sleep, movement, nourishment, connection, or quiet.
Our bodies participate in everything we design. They carry our ambitions and responsibilities, our relationships and disappointments, our celebrations and worries, our meals and sleepless nights, our long walks, periods of grief, and moments of peace.
They carry our lives.
Epigenetics and telomeres allow us to look beneath the surface and glimpse some of the extraordinary biology responding along the way. We need enough understanding to become more aware, enough awareness to notice our patterns, and enough clarity to decide whether those patterns support the life we want to live.
Then we can make choices: protect sleep more deliberately, move our bodies because they were built to move, nourish ourselves with greater intention, create room for recovery, and pay attention when chronic stress has quietly become our normal state.
These choices are ordinary. That may be exactly why they are so easy to underestimate.
How Life Gets Under the Skin
The children conceived during the Dutch Hunger Winter could not choose the environment in which their lives began. Six decades later, scientists found evidence that those early conditions were still reflected in aspects of their biology.
Their story reminds us how responsive and complex a human life can be.
We begin with an inheritance we did not choose, and then life happens. Our bodies respond, adapt, repair, age, and continue carrying us forward.
Some of what shapes us comes from circumstances beyond our reach. Some of it grows from the way we live every day. Understanding that difference gives us awareness, and awareness gives us a place from which to choose.
The more we understand about how life gets under the skin, the more intentionally we can choose how we live.
Live by Design, Not by Default.
Until the next horizon,
Coach • Traveler • Believer in Intentional Living
