Not written in stone – how our lifestyle affects gene expression
Updated: Sep 12, 2020
Of all the ways we think about actively changing and improving our health, our “genes” are generally not one of them. And with good reason: we’ve been taught to believe that our genes are fixed and unchangeable. This idea is particularly misleading because it suggests a larger misconception: biology as destiny. And as long as we continue to blame our genes for our health, weight or mood problems, then we allow biology to define who we are. In contemporary society, where our freedom of choice seems nearly unlimited, it’s ironic that genetics has become so deterministic.
In fact, our genetic inheritance is not written in stone. Instead, our genes are fluid, dynamic and responsive to everything we think and do. Epigenetics is the study of how the outside world – the air we breathe, the food and medications we consume, the experiences we have – alter our genetic activity and affect the way our genes are expressed. While it has long been assumed that our genes are controlled by nature – our pre-determined constitution – it turns out that a large part of how they are expressed is driven by how we nurture ourselves. While it is true that our genes may predispose us to obesity, depression, cancer or type 2 diabetes, they do not promise it. In truth, our genetic activity is largely under our control.
DNA is responsive to everything that happens in our lives.
Epigenetics is a relatively new branch of genetics that has been heralded as the most important biological discovery since DNA itself. In a world where we think there is little left to explore, the human genome is a new frontier. Research clearly shows that genes get turned “on” and “off” – and are expressed to greater or lesser degrees – depending on a wide range of lifestyle choices. Factors such as diet, physical activity, stress and toxic exposure can all cause changes to the epigenome that alter the activation of certain genes. This is how our everyday lifestyle choices can have very real repercussions at the genetic level, changing our risk of some of the most common diseases facing society today. While no single choice we make about food or exercise is likely to dramatically impact our health or gene activity, over time, our daily habits and conscious choices do impact the expression of our gene activity, including:
- Improving our mood level (anxiety and depression)
- Gaining more energy
- Reducing chronic stress
- Returning to normal restful sleep
- Resisting seasonal colds and flu
- Relieving persistent aches and pains
- Normalizing metabolism
- Slowing the aging process
- Decreasing the risk of cancer and other serious illnesses
The promise of epigenetics can be seen everywhere – what we eat, where we live, who we interact with, when we go to sleep, and how much we exercise. All of these factors cause chemical modifications that can change our gene expression. Importantly, epigenetics focuses on our power to change gene activation, not the actual DNA sequence of the genes themselves. While the genetic “inheritance” our parents passed on to us does not change – our unique blueprint stays the same throughout our lifetime – gene activity or expression is remarkably flexible. And with more than 20,000 genes, there is an infinite combination of health outcomes that may happen as the result of certain genes being activated or deactivated.
The human genome
DNA is the code our body uses to build and rebuild itself. But genes themselves need instructions for what to do, and where and when to do it. While genes themselves don’t change as a result of the environment, the environment does affect the instructions our genes receive.
The Greek word epi means “upon,” so epigenetics is the study of what is on top of genetics. Physically, epi refers to the sheath of proteins and chemicals that cushion and modify each strand of DNA. While there are several dynamics that can potentially drive the alteration or modification of gene expression – how the information in a gene gets translated into proteins – the two main ones involve methyl groups and histones. Methyl groups turn genes on and off (like a light switch) while histones regulate gene activity up or down (more like a thermostat). It’s thought that we have four million of these switches that are triggered by lifestyle and environmental factors.
Every cell in our body – and every gene contained within – eavesdrops on what we think, say and do – and reacts to it. Our actions become the messages or instructions we send to our genome: drinking orange juice each morning, eating an apple with the peel on, lowering the noise level at home, or taking a relaxing walk before bedtime. Epigenetics shows us that we can be a part of that conversation and even help control it. Instead of being at the mercy of our genes, epigenetics shows us how we can alter the activity and expression of genes to our benefit. Lifestyle is the domain where this transformation take place, and the dozens of ordinary choices we make every day represent an enormous amount of untapped potential to help us activate good health and vitality. These include: Do I go to the gym or sleep late? Do I gossip at work or mind my own business? Do I donate money to charity or enlarge my own savings account? Do I stop for fast food or make myself a salad once I get home?
Of course, not all genes are susceptible to modification. There are critical periods in our development during which certain genes may be influenced before they go silent. For example, the genes that control the structure of our body: we have only one window of time during which to build arms, legs, teeth, etc. During this window, things like drugs, maternal illness and nutrition can affect genetic expression. Once that window closes, we cannot “will” our body to grow a new tooth or replace an amputated limb.
Lifestyle versus genetics
Only 5% of disease-related gene mutations are fully deterministic, while 95% can be influenced by diet, behavior, and other environmental conditions. Studies show that a program of positive lifestyle changes can alter between 4,000 to 5,000 different gene activities. The concept of epigenetics empowers people to take control of their health by making choices that may override their genetic code. Increasingly, research shows how specific behaviors, lifestyle choices, and the environment all affect how our genes are expressed.
We are more than our genes
Nutritionists have long known that “you are what you eat” is not just an expression. But now we know that the nutrients in our food interact with our genes – not surprisingly, the study of this interaction is known as "nutrigenomics." Research shows that our diet affects the epigenome in several tissues that are important for metabolism. For instance, eating a high-fat diet for five days led to changes in both the gene activity and DNA methylation patterns in skeletal muscle and adipose tissue. Alternately, compounds like sulforaphane (found in broccoli), curcumin (turmeric), epigallocatechin gallate (green tea), and resveratrol (wine) can all slow or potentially reverse DNA damage.
It’s well accepted that physical exercise is one of the best things you can do for your overall health and mental well-being. There is now evidence that physical exercise can also positively affect gene expression. A recent study of the brains of elderly mice found 117 genes were expressed differently in the brains of animals that ran regularly, compared to those that were sedentary. Several studies (among humans) have shown that exercise impacts DNA methylation and the function of genes in skeletal muscle and adipose tissue.
The quantity and quality of our sleep also disrupts genetic activity. Research reveals that just a single week of insufficient sleep can alter the activity of over 700 genes. The expression of genes affected by sleep deprivation help govern circadian rhythms, metabolic functions, and sleep homeostasis—the regulation of sleep itself.
Lastly, the environment itself can alter our health by affecting the proteins that turn genes on and off. Indeed, as many as half the genes that cause familial or inherited cancer are turned off when pollutants in the environment affect these proteins. And because they are turned off, these genes can no longer suppress tumor formation or repair DNA, allowing cancerous cells to take root and multiply.
In addition to the tangible decisions related to diet, exercise and sleep, gene expression is also affected by intangible factors such as stress, our relationships, and our thoughts. One of the most powerful stress reduction techniques, mindfulness meditation,turns down the expression of pro-inflammatory genes, thus reducing inflammation. Importantly, chronic inflammation is an underlying cause of seven of the top ten leading causes of death including cancer, heart disease, diabetes, and Alzheimer’s. While you might expect that you’d have to meditate for years to sufficiently change gene expression, measurable changes have been observed in as little as eight hours of meditation (with more prominent effects displayed among long-term, experienced meditators).
Dr. Dawson Church, award-winning author of Epigenetic Medicine and the New Biology of Intention, cites over 400 scientific studies that show how intangibles such as the expression of gratitude, acts of kindness, optimism, and mind-body healing techniques such as acupuncture and EFT, all positively affect the expression of our genes. And just as with meditation, their epigenetic benefits are often experienced almost immediately.
Of course, it’s not only positive habits that affect our genes. Substance abuse, addictions, inactivity, malnutrition, and exposure to toxins all negatively affect the way our genes express themselves. Research shows that emotional factors such as trauma and stress can also activate harmful epigenetic changes.
An early example of gene expression
One of the most striking cases of the environment altering gene expression can be found in an early study of the homogeneous population of the Berbers from North Africa. Researchers studied desert nomads, mountain agrarians, and coastal urban residents; all were Berbers with low genetic variance. Yet, while they had very similar genetic patterns (since they were all from the same basic genetic stock) they had very different living situations.
Researchers analyzed the white blood cells of the group to study the impact of the transition from traditional to urbanized lifestyles on the human immune system. While Berbers from the urban environment showed evidence of up-regulated respiratory and immune genes, those same genes lay relatively dormant in nomadic and agrarian Berbers. Overall, gene expression between the three groups varied by up to one-third based on geographic location and corresponding lifestyle.
Identical twins provide clues
The study of identical twins (who, by definition, have identical genetic material) has also provided a unique window into epigenetic changes. The effect of lifestyle factors is so strong that gene activation between identical twins can diverge significantly over the course of their lives. Research shows that as identical twins age – and spend time apart – the expression of their genes become less alike. Depending upon their experience in the world and how this translates into genetic activity, one twin may be obese, the other lean; one may be schizophrenic and the other not; one may die young, while the other lives a long life.
While epigenetics is one of the most exciting new areas of scientific enquire, it is also one of the most easily misunderstood. After his historic journey in space, many newspapers reported that astronaut Scott Kelly's genes were changed so much so that he and his identical twin were no longer identical. These articles confused genetics – our DNA – with epigenetics – the chemicals and proteins that surround our DNA and influence how they work. Importantly, Kelly's DNA did not change – his genes were still identical to those of his twin brother. But the experience of living in space for almost a year did alter his epigenetics and the expression/activity of his genes. Fortunately, we do not need to leave Earth to change our own epigenome.
DNA and aging
Studies show that as we age, the expression and activity of our DNA changes – a lot. In particular, the process of aging is characterized by significant variation in the epigenome where genes lose or gain new methylations. Researchers in Iceland and the U.S. have found that over a period of 10-15 years, some people's DNA changed as much as 20%. Importantly, these differences aren't in the famous building blocks A, T, C, and G's of DNA itself. Instead, they are changes in DNA methylation. How significant is 20%? Given that there are millions of spots on human DNA that are methylated, a 20% change represents tens or even hundreds of thousands of changes. Given that aging is associated with increased abdominal obesity, cardiac disease, insulin resistance, type 2 diabetes and Alzheimer’s, a better understanding of the age-related mechanisms of epigenetics could lead to new and preventive treatment methods for many chronic, devastating diseases.
You are not your genes
Epigenetics reveals how our lifestyle, mindset and environmental circumstances can awaken individual genes and/or suppress others. Here are specific ways we can alter our environment and lifestyle to improve our body-mind-spirit and epigenome.
1. You are what you eat.
Food and nutrition matter greatly – healthy nutrition awakens essential genes that have a positive impact on your mind and body.
- Eat a balanced, whole diet heavy in fresh fruits and vegetables
- Add anti-inflammatory foods to your diet (berries, seeds, olive oil, dark leafy greens)
- Switch to whole-grain breads and cereals
- Eat fatty fish at least twice a week (fresh salmon, tuna, sardines)
- Eliminate processed foods
- Limit alcohol and red meat consumption
- Eat a side salad with lunch or dinner
- Drastically reduce white sugar (and all white foods)
- Add probiotic foods / supplement to your diet (yogurt, sauerkraut, kimchi)
- Consider becoming a vegetarian / pescatarian
- Maintain a healthy weight
2. Stress alters gene expression.
Everyone experiences stress – modern life is stress. The surge of stress hormones (primarily cortisol and adrenaline) lead to a cascade of physical reactions that impact on our health and gene expression. If you’re chronically stressed out, certain useful genes may gradually become suppressed or de-activated as they help you “cope.”
- Calm the mind with a daily meditation practice
- Allow your life to unfold naturally, and try to avoid a hectic schedule
- Focus on one thing at a time and avoid multi-tasking
- Taking time out every day to let your body, mind and spirit reset
- Avoid people who are sources of pressure and conflict
- Minimize background noise and distractions at home
- Practice self-care regularly
- Find a physical outlet to unwind from daily stress
- Stop taking on too much responsibility
- Spend time out in nature every day
3. An active lifestyle awakens the best genes.
A daily routine that makes time for regular exercise influences the positive expression of genes as your body activates the genes needed to support a vital healthy lifestyle and engaged mindset. Finding ways to move your body that you enjoy creates new pathways in the brain that quickly become a habit.
- Take a brisk walk after dinner every night
- Seek out new friends that lead an active lifestyle
- Resume a sport you used to love, or participate in, during school
- Start a yoga practice
- Get sufficient sleep (at least 8 hours) every night to wake up feeling refreshed
- Avoid sitting for long periods by moving your body at least once an hour
- Engage in a mix of cardio and strength training
4. Change your environment.
Sometimes changing your environment isn't as easy as influencing other aspects of your life, but you can control it in small ways. Regular exposure to nature or a simple change of scenery can activate your mind, body, mood and better genes.
- Clear the clutter from your home and work environment
- Turn your bedroom into a soothing, calming sanctuary
- Take a mid-afternoon break to listen to music or an inspirational podcast
- Start every day by exposing yourself to morning sunlight
- Connect with nature: walk barefoot on the grass or feel the wind on your skin
- Avoid toxic chemicals, especially in skin care and household cleaning products
5. Find deeper emotional fulfillment and meaning.
Even though happiness is a mental state, the physical body is deeply affected by our moods. Chemical messages tell every cell how we’re feeling. Making your life more meaningful is just as important of a lifestyle choice that impacts gene expression as is diet or exercise.
- Consciously express gratitude daily
- Relish your creativity
- Do or say something nice every day that brings someone happiness
- Identify one self-defeating habit you have and develop a plan to overcome it
- Write down your personal vision of a more purposeful life
- Nurture acceptance for others as your equals, without judgement or prejudice
- Let the flow of life bring you what you need, without trying to control it
We are not simply the sum total of the genes we were born with. Rather, we are the author of our biological story. Each of us has multiple, future possible versions of ourselves – and it’s up to us to make lifestyle choices that direct genes toward fat burning, muscle building, longevity and wellness (and away from fat storing, muscle wasting, disease and illness). Certainly, we can’t ignore our genes – they do matter. But equally important, we need to understand how our particular genes interact with diet, exercise, sleep, sun, nature, socializing, and all of our other lifestyle choices.