Your Comprehensive Guide to DNA Testing
“The laws of genetics apply, even if you refuse to learn them.” — Alison Plowden
What began in the early 80s, has since evolved into a highly complex DNA testing process. Whether people want to find out where their relatives are from or if they may be at an increased risk of disease. All this has now become possible through genetic testing.
Although there are still limitations, when it comes to your health, genetic testing can unlock clues in regards to your potential future. That way, you can address modifiable lifestyle factors which impact gene expression.
If you’re interested in learning about the vast and interesting world of DNA testing, then keep reading!
What Is DNA Testing, and Why Should We Care About It?
When many people think about DNA testing, they immediately picture all kinds of science experiments gone wrong. Although there are some controversial areas in regards to genetic testing, DNA testing is an identification tool that has many practical and professional applications.
Most used in relation to parental testing, forensic testing, and gene therapy. This area of research has since branched out, covering everything from ancestry to more personalized nutrition known as nutrigenomics. Regardless of the application, genetic testing involves the analysis of DNA code sequences.
Each human shares around 99.9 percent of the same DNA. It is that 0.1 percent of code sequences that make us unique. From eye color to key personality traits, our DNA can unlock so many clues. For example, when testing whether a person is a biological parent to a child, samples taken to compare genetic markers.
These “markers” are what help us identify one species from another. As well as one individual human to the next. Researchers are able to use key markers to locate a disease-causing gene. This is valuable. In turn, this can help scientists track various inherited traits through generations.
More on family history
As reported by the Centers for Disease Control and Prevention, “Family history is important for your health.” For example, if your family has a history of stroke or cancer, then you may face a higher than normal risk of developing these conditions as well.
Although you cannot change your genetic makeup, this level of awareness can help you reduce your risk. When it comes to key features that increase your risk in relation to family history, these include:
As discussed below, understanding your risk (which can be further understood through genetic testing) is often influenced by lifestyle variables — diet and exercise.
What does it all mean and why does DNA testing matter?
DNA testing as we know it today became possible following the initiation of the Human Genome Project, which first began in 1990. This project resulted in many benefits, especially in regards to medical advances. This is particularly the case regarding cancer, as it is a genomic disease (which results from the loss or gain of chromosomal material).
Some of the core advantages associated with DNA testing include, but are not limited to:
The ability to better predict (and prevent) disease. For example, if you carry a gene that may predispose you to a certain disease, physicians can offer preventive treatment plans, which will often focus on key lifestyle variables.
Allows for progression in regards to personalized medicine, as each individual reacts differently to both disease and treatments. Based on our understanding of certain genes, physicians could offer tailored treatment plans which consider each patient’s specific needs.
The development of a more accurate diagnosis process, especially in regards to conditions that are challenging to diagnose during the early stages. Although a lot of research is still required, this is of particular interest among the Alzheimer’s and dementia community.
Significant improvements in forensic science, as genetic testing helps investigators verify whether or not someone was at the scene of a crime. In the future, it may be possible to identify what a suspect looks like based on the DNA collected from a crime scene (i.e. their skin color, hair color, hair color, etc.)
How Are DNA Tests Conducted and What Do The Results Mean?
In order to conduct a DNA test, a blood, hair, skin, fluid, or tissue sample is required. As at-home genetic testing continues to evolve, the majority of these tests require a simple cheek swab. Once a sample is collected, it is then analyzed in a lab. By examining key changes in DNA, chromosomes, or even proteins, technicians can come to a more specific conclusion.
Your results can tell a fairly complex story, one that may bring a sense of relief or an increased feeling of fear. After all, knowing that you carry a gene that increases your risk of cancer isn’t the most encouraging news — but it can provide with an advantage moving forward.
However, it is important to note that the results of genetic tests are not always black and white. In some cases, they can be challenging to interpret. When taking a test provided by 23andMe, for instance, their genetic health reports will tell you whether or not you carry certain gene variants or not, and what that means in terms of your potential risk.
For example, when testing for late-onset Alzheimer’s disease, researchers focus on APOE4, which is a variant of the APOE gene. If this variant is detected based on your genetic material, you will face an increased risk of developing this disease. However, there is often more to the story, as these results do not consider genes linked to early-onset or other possible variants associated with this disease.
Then there are the lifestyle and environmental factors that need to be taken into account, as researchers believe that 1 in 3 cases of dementia is preventable. After all, managing lifestyle factors such as diet, exercise, stress, and sleep, all play a role — not to mention the proper management of conditions such as hypertension or diabetes. In other cases, finding out that you carry a certain gene variant could be life-changing. A classic example of this would be BRCA1 and BRCA2 variants, which increase your risk of certain types of cancer. Once again, although these results do not act as a diagnosis, they could encourage immediate screening. After all, “an ounce of prevention is worth a pound of cure.”
Bottom line: Genetic testing supports greater awareness surrounding our health. Although many seek answers surrounding genealogy records, the potential of DNA testing is immense in terms of long-term positive health. Knowledge is power, promoting proactive action.
The Relationship Between DNA Testing and Lifestyle Variables
The public is well aware of the risks associated with certain lifestyle behaviors. Smoking is a great example, as it has been linked to a wide range of chronic conditions — it is also a modifiable risk factor. Considering nearly 38 million American adults smoke cigarettes, it is important that these individuals become aware of individualized risks. A recent review, published in Lifestyle Genomics, focused on genetic testing and lifestyle behavior change. What they found was that it is possible to facilitate change, based on genetic testing. Of these changes, the most promising were those associated with nutrition.
In more recent years, researchers have shown that the saying, “genetics loads the gun and lifestyle pulls the trigger” to be fairly accurate. This means that if you are someone who is genetically predisposed to a higher risk of heart disease or diabetes, your lifestyle choices could essentially tip the scale. Since specific genes have been linked to everything from obesity to heart disease, it is now possible to study the impact of lifestyle modification.
As stated by Dr. Vimal S Karani, a Lecturer in Nutrigenetics, “We examined if the association between MC42 and TCf7L2 genes, and cardio-metabolic traits is modified by dietary factors and physical activity. We found that individuals who consumed a low-fat diet had higher levels of good cholesterol despite carrying the risky gene variant.”
What the Research Has to Say
That is why it’s imperative that you understand your family history, especially in regards to heart disease, diabetes, and cancer. Your day-to-day choices DO matter, and in many cases, regulate gene activity. Perhaps one of the most groundbreaking experiments was the study published by researchers at Duke University.
They were able to show that mice who carried the agouti gene were obese, diabetic, yellow-haired, and faced a greater risk of cancer. However, once these mice were fed methyl-rich foods, mainly those that were rich in folic acid and B-vitamins, this change in diet impacted their offspring.
Instead of being born with the same genetic predispositions, when mice were fed an improved diet before and during pregnancy, their offspring were brown, thin, and the gene in question was repressed. This means that this gene was essentially “turned off,” improving the health of the next generation.
They concluded that what you eat can increase or decrease the likelihood that your children will suffer from a certain genetic disease based on the process known as DNA methylation. They made suggestions for any mom-to-be, recommending a diet rich in folic acids from sources such as dark leafy greens and beans. Vitamin B and B12 are also critical.
Genes, Lifestyle Choices, and Lifespan
At the end of the day, humans care about their health for one main reason — they want to live a long, healthy life.
In a recent review, published in Nature, it was found that the choices we make do play a role in regards to our lifespan. The goal was to better understand which lifestyle and genetic factors impact how long we live.
Analyzing data from 25 different population studies, spanning three continents and more than 606,00 people, it was found that two genetic variations impact lifespan.
The researchers stated that this was the first time that the role of genetic variations in relation to life expectancy has been confirmed. They also noted that other genetic traits, such as those that predispose us to an addiction, can also impact life expectancy. Overall, the top influencers in life expectancy were one’s weight, whether they smoked, and their level of education. In fact, they found that smoking a pack a day reduces lifespan by seven years. These types of studies show us how far genetic testing has come, and what it means for public health. We are all aware that smoking is bad for us and that being overweight is unhealthy. When you put a number to it in terms of years lost within your lifespan, this can initiate real action. Curos will continue to cover some of the latest research and developments in this area, focusing on practical ways for you to improve your health. Remember, your genetic material is just one piece of the puzzle. Although your genes play a vital role, you are not powerless to your DNA. The choices you make today will impact your health tomorrow.
To learn more, follow the content published in our journal, and always remember, “The secret of your future is hidden in your daily routine.”
Develop habits and build a routine that guides your genes in a positive direction, supports your health and allows you to regain control.