Epigenetics is a relatively new branch of genetics that has been heralded as the most important biological discovery since DNA. Until recently, it was believed you were stuck with the genes you were born with. But now it’s known that your genes get turned on and off and are expressed to greater or lesser degrees depending on lifestyle factors. Let’s take a look at what epigenetics is, how it works, and what you can do to improve your chances in the health lottery.
What Is Epigenetics?
The “epi” in epigenetics is derived from the Greek word meaning “above” or “over.” Epigenetics is defined as the study of any process that alters gene activity without changing the DNA sequence. More simply, it is the study of gene expression — how external factors turn genes on and off, and up and down.
The Human Genome Project has identified 25,000 genes in human DNA. DNA is widely regarded as the code the body uses to build and rebuild itself. But genes themselves need instructions for what to do, and where and when to do it.
Epigenetic modifications, also called “tags,” provide the instructions. Several of these tags have been discovered, but the two main ones involve methyl groups (made of carbon and hydrogen) and histones (a type of protein). To imagine how tags work, think of a gene as a lamp. Methyl groups act as an on-off switch that turn a gene on or off. Histones, on the other hand, act like a dimmer switch, regulating gene activity up or down. It’s thought that we have four million of these switches that are triggered by lifestyle and environmental factors.
Identical Twins Provide Clues
The study of identical twins, who have the same genetic material, has provided researchers with a unique window into epigenetic changes. The effect of lifestyle factors on genes is so strong that genes of identical twins can diverge significantly during the course of their lives. Research shows that as identical twins age, especially ones that spend the most time apart, their genes become less alike.
You might expect that identical twins would have similar health histories, yet they exhibit vastly different incidences of many diseases including mental disorders such as alcoholism, Alzheimer’s, bipolar disorder, and schizophrenia and physical disorders such as diabetes, cancer, Crohn’s disease, and rheumatoid arthritis. This is due to epigenetic drift — a change in gene expression over time.
Lifestyle Factors Affect Your Genes
Dr. Rudolph Tanzi is a professor of neurology at Harvard University Medical School. Among his many accomplishments, he co-discovered three genes that cause early onset familial Alzheimer’s disease. Along with Dr. Deepak Chopra, global leader in the field of mind-body medicine, he co-authored Super Genes: Unlock the Astonishing Power of Your DNA for Optimum Health and Well-Being.
In Super Genes they write: ”Only 5% of disease-related gene mutations are fully deterministic, while 95% can be influenced by diet, behavior, and other environmental conditions. Current models of well-being largely ignore genes, yet studies have shown that a program of positive lifestyle changes alter 4,000 to 5,000 different gene activities.” Tanzi and Chopra go on to say: “You are not simply the sum total of the genes you were born with. You are the user and controller of your genes, the author of your biological story. No prospect in self-care is more exciting.”
This is exciting news! It means that you’re not at the mercy of your genetic makeup at birth. You actually have a great deal of control over your health and your future no matter what genetic hand you have been dealt. The field of epigenetics is in its infancy and there is still much to learn, but so far the evidence shows that there are many fundamental lifestyle factors that can alter gene expression.
Diet, Sleep And Exercise Modulate Gene Expression
Not surprisingly, diet can affect the health of your DNA. A diet high in refined carbohydrates that promotes high blood glucose attacks your DNA. On the other hand, compounds like sulforaphane (found in broccoli), curcumin (turmeric), epigallocatechin gallate (green tea), and resveratrol (wine) can slow or potentially reverse DNA damage.
Inadequate sleep also disrupts genetic activity. A team of researchers that included sleep science and genetics experts examined the influence of sleep on gene function and discovered that just a single week of insufficient sleep altered the activity of over 700 genes.
It’s well accepted that physical exercise is one of the best things you can do for your overall health and mental well-being. Now there’s evidence that physical exercise can positively affect gene expression. A recent study of the brains of elderly mice found 117 genes that were expressed differently in the brains of animals that ran regularly, compared to those that were sedentary.
So Do Stress, Relationships, And Thoughts
Not only do tangible factors like diet, sleep, and exercise affect your genes, so do intangibles like stress, your relationships with others, and your thoughts. One of the most powerful stress reduction techniques, mindfulness meditation, turns down the expression of pro-inflammatory genes thus reducing inflammation. Chronic inflammation is an underlying cause of seven of the top ten leading causes of death including cancer, heart disease, diabetes, and Alzheimer’s.
You might expect that you’d have to meditate for years to change gene expression sufficiently, but measurable changes have been observed in as little as eight hours of meditation. However, these effects were stronger in experienced meditators than in those new to the practice.
Dr. Dawson Church is an award-winning author whose bestselling book, Genie in Your Genes: Epigenetic Medicine and the New Biology of Intention, has been hailed as a breakthrough in the field of epigenetics. In his book, Church cites over 400 scientific studies that show how intangibles like the expression of gratitude, acts of kindness, optimism, and mind-body healing techniques like the Emotional Freedom Technique positively affect the expression of genes. And just as in the meditation study, these epigenetic benefits were often experienced immediately.
It’s not only positive habits that affect your genes though. So do the bad ones. Substance abuse, addictions, inactivity, malnutrition, and exposure to toxins negatively affect the way your genes express themselves. Researchers have found that emotional factors such as trauma and stress can activate harmful epigenetic changes.
There are numerous diseases thought to have an epigenetic component including asthma, Alzheimer’s, cancer, diabetes, immune disorders, kidney disease, glaucoma, muscular dystrophy, and pediatric syndromes as well as many psychiatric disorders including autism, schizophrenia, and bipolar disorder. In 2008, the U.S. National Institutes of Health committed to investing $190 million into epigenetics research to hopefully find new and better ways to treat these diseases.
Epigenetics Changes Last For Generations
One of the most amazing and controversial discoveries is that epigenetic changes don’t stop with you. Epigenetic signals from the environment can be passed from one generation to the next, sometimes for several generations, without changing a single gene sequence.
According to Dr. Mitchell Gaynor, author of The Gene Therapy Plan: Taking Control of Your Genetic Destiny with Diet and Lifestyle, “One’s DNA, it turns out, is not fixed at all, and outside influences — lifestyle, thinking, nutrition, nurturing, and environmental factors — actually influence the way genes express in our bodies. In fact, we now know that genetic expression comes from generations before us and will continue for the generations after us. Today, the debate is not nature versus nurture. We have evolved into understanding that it is nature plus nurture.”
Dr. Randy Jirtle is a pioneer in epigenetic research. He holds two U.S. patents on imprinted genes and has published more than 170 peer-reviewed articles. “Epigenetics is proving we have some responsibility for the integrity of our genome,” Jirtle says. “Before, genes predetermined outcomes. Now everything we do — everything we eat or smoke — can affect our gene expression and that of future generations. Epigenetics introduces the concept of free will into our idea of genetics.” In fact, some of his research shows that epigenetic changes may endure in at least four subsequent generations.
The implications of this are profound. What you do today could affect the health and behavior of your grandchildren just as what your grandparents did affects your health today.
Epigenetics is a complex topic with potentially far-reaching consequences. To bring the concepts involved down to earth, I recommend this slightly offbeat video from SciShow. It explains how epigenetics works using the analogy of two hypothetical twins separated at birth and raised under very different circumstances.