Discovering DNA and mapping the human genome was a major feat of modern medicine. Are our genes all-important when it comes to aging and overall health?
Even though DNA and genes are important in determining health, research has shed new light on the aging process. As it turns out, DNA is only part of the story. Here, we’ll learn more about human genetics, our DNA, and why lifestyle matters more in aging than you may think.
Human Genetic Material: What is DNA?
Our interest in what makes us who we are has a long history, but we can start with the father of modern genetics, Gregor Mendel. Mendel was a monk who became curious after tending his monastery’s garden. As he cared for the garden’s peas, he began to wonder why some were smooth and others wrinkled. He followed his curiosity and developed experiments that bred generations of peas. He noted the differences that occurred based on the varying parent strains.
Mendel’s experiments paved the way for future leaders in genetics, like the famous Watson and Crick. In 1953, Watson and Crick discovered DNA and its characteristic double helix shape. Since these groundbreaking discoveries, we now understand that every living cell has a nucleus containing the body’s genetic blueprint.
Most body cells (except for reproductive cells) contain 23 pairs of chromosomes. Each chromosome is composed of genes, which are further composed of DNA. In contrast, the reproductive cells (sperm and ova) contain only unpaired chromosomes. When a sperm and ova combine to form a fetus, the chromosomes join to make complete pairs.
DNA Base Pairs
DNA is our body’s way of communicating information. It uses molecules called “bases” to create a language encoding characteristics, traits, and functions for every cell of the body. These bases join together in pairs and form a ladder of genes that we know as the double helix.
- A – Adenine. Pairs with Thymine.
- T – Thymine. Pairs with Adenine.
- G – Guanine. Pairs with Cytosine.
- C – Cytosine. Pairs with Guanine.
These bases match up in pair formation and have designated normal matches (A with T and G with C). If alternative pairings do occur, genetic issues or abnormalities often result.
The specific pattern in which genes code determines the phenotype. Phenotype makes up the physical characteristics of an individual, such as eye color, height, or propensity to skin cancer or heart disease.
The Outdated “Central Dogma”
The discovery of DNA changed medicine forever. This opened the door for amazing advances in medicine, but this theory focused on genes as the sole determining factor for health. This dogma is now outdated and science has moved to a more comprehensive theory through the field of epigenetics (discussed below).
DNA and Inherited Aging Disorders
Accelerated aging diseases, or progerias, are an inherited form of aging. One such condition, Werner’s Syndrome, causes rapid aging and early onset of age-related disorders like arthritis and cancer. In Werner’s Syndrome, a specific DNA abnormality prevents the function of the gene coding for an enzyme called helicase. Helicase causes damaged DNA to unwind so it can be repaired and returned to a healthy state. Unfortunately, for those with Werner Syndrome, the lack of helicase means that damaged DNA does not get repaired, and the effects of aging, sun exposure, and other issues build up quickly.
DNA and Acquired Aging Disorders
DNA plays an important role in skin health, affecting both inherited genetic traits as well as acquired characteristics. While some health conditions are inherited through DNA, others are acquired after birth through lifestyle.
One of the most common examples of acquired DNA damage is skin cancer. When skin cells are damaged by sunlight, so is their DNA. Under a microscope, sun-damaged skin cells look enlarged, foamy, and pink. Their nuclei inside the cells are purple and shrunken. These cells are often so damaged that they undergo the process of apoptosis or programmed cell death.
Programmed cell death is initiated by the damaged cells themselves. They sense that their DNA is damaged to an extent that would prevent them from properly functioning and reproducing. But apoptosis does not always go according to plan. In some cases, the damaged cells fail to self-destruct and they do reproduce in their damaged state, creating more severely damaged cells with a high likelihood of becoming skin cancer.
After just 20 minutes of sun exposure without sunscreen, the skin shows severely damaged cells under a microscope. In contrast, skin treated with a broad-spectrum sunscreen (EXTREME PROTECT SPF30) shows no sign of DNA damage. This makes the possibility of developing skin cancer low. Using sunscreen is the best way to protect against acquired DNA damage from sun exposure.
Epigenetics, Lifestyle, and Aging
While we cannot change the genes we were born with, we can certainly influence the genes we have.
The example of the two skin samples following sun exposure illustrates how individual choices determine the extent of our acquired DNA damage. In this instance, wearing sunscreen profoundly reduces the risk of developing skin cancer.
This is an example of epigenetics: the impact of life choices on our genetic material and health outcomes. Epigenetics means “above the gene” or “over the gene” and illustrates that how we live can have a bigger impact than our predetermined set of genes.
Epigenetics is a fairly new field of research, but already shows we have more control over our longevity than we may think. In fact, according to epigenetics expert Blair Justice, PhD, genes may only determine up to 35% of our potential longevity. The bigger factors at play are lifestyle, diet, environment (including sun exposure), social support systems, and more.
Mental Attitudes and Epigenetics
Mental attitude and habits are a key feature of epigenetics. Consider the “heart attack-prone” personality. These types are Type A, likely to work too hard, be overweight, sedentary, and deny physical symptoms of distress or put off getting medical help.
Another example is the “cancer-prone personality.” These types tend to be self-sacrificing, put others before themselves, and be depressed. Studies show that depression weakens an important aspect of our body’s cancer defense system – the Natural Killer (NK) cells – preventing them from seeking and destroying cancer cells.
Spotlight on Proteomics
An aspect of epigenetics is proteomics, the science of how proteins can determine if a given gene will be expressed or not. According to proteomics, our lifestyle choices can cause proteins to turn certain genes “on” or “off.” For example, someone may have genes giving them a predisposition for heart disease. Personal decisions and lifestyle can activate or suppress these genes, turning them “on” or “off.”
Genetic Make-Up is Just the Beginning
With new research in the developing field of epigenetics, it is safe to say that the old dogma of early geneticists is outdated. Our health is not entirely determined by our DNA – we can make impactful choices that steer us towards better (or worse) outcomes.
Aesthetics professionals help their clients understand that choices matter. With conversations centering around the skin, it can be explained how habits like sunscreen use, diet, exercise, and the best skincare can optimize health, helping to prevent both aging and disease.