Even though genetics is a topic that comes up in high school science, many people graduate without retaining much of that knowledge. Despite its complexity, genetics is an important topic to know and understand. The more you learn about genetics, the easier it will be to recognize how genetic variation affects the unique aspects of your health, appearance, personality, and behavior—including your eating habits.
One of the most interesting aspects of genetics research is how our collective knowledge of genes and their impact on disease and health care is expanding daily. From Charles Darwin’s collection of genetic data in the 1800s to support his theory of natural selection, to modern research and studies about the human genome, we are continually unearthing new knowledge about the genetic code, which we’re then able to apply to our daily lives in a way that keeps us healthier long-term.
The next level of genetic study is the field of nutrigenomics, which studies how the nutrients you eat impact your genes and how your body responds to nutrients. It is the basis for personal eating plans and DNA-informed diets.
For now, let’s explore the basics of genetics, including how these building blocks of human life affect our eating habits and our ongoing relationship with food.
What is a Chromosome?
Chromosomes are structures containing genetic information that are found in the nucleus of each cell and are central to its creation. Without our chromosomes, our cells would not know how to grow and reproduce effectively, leaving us unable to function. As you may recall from the human genetics branch of biology, the way we inherit our genes from our parents is through chromosomes.
We receive 23 chromosomes from each parent, which are paired together for a total of 46. Each pair of chromosomes contains one from each parent. You can find the same 46 human gene chromosomes in the nucleus of almost every cell in our body, with the exception of our reproductive cells.
Inside each roughly X-shaped chromosome is a coiled strand of DNA, which is wound around a protein called a histone which helps it keep its shape. Without the histone, the DNA would stretch into a length far too long for any cell to contain.
Learn more about chromosomes in our focused article “An Introduction to Chromosomes”
DNA stands for deoxyribonucleic acid. It is the genetic material that carries all the necessary information to tell living things how to function. It also is the basis of all of our hereditary features, from eye color to genetic disorders.
The basis of passing down our hereditary features is a process called “Mendelian inheritance,” which describes how recessive and dominant attributes are handed from generation to generation. It is named after Gregor Mendel who experimented with pea plants in the 1800s.
DNA is made up of molecules known as nucleotides, which come in four different types: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G), which are matched into two base pairs each and are attached to a sugar molecule and a phosphate molecule. Each nucleotide is arranged into DNA’s characteristic spiral, called the double helix.
During cell division, the DNA strand splits along the middle of the double helix, and each separate piece of the strand acts as a base for creating a new piece of DNA material in a new cell.
Take a deep dive into your DNA and read our DNA Refresher article.
What is the Function of DNA?
DNA exists to store all the information that our cells need to develop, function, and reproduce. It’s easiest to think of it as an instruction manual or fact sheet that can be found in all our cells to ensure that each one functions as it should.
If DNA is not accurately copied every time that it divides itself, it can lead to disease or illnesses like leukemia, which is caused when genetic change occurs in chromosomes and defective versions alter the way your red blood cells reproduce.
Within our DNA, specific sequences of nucleotides called genes provide our cells with instructions on creating proteins that help our bodies function. They go by many names, including enzymes, hormones, and antibodies; these are different types of proteins.
Proteins are responsible for the healthy functioning of all the tissues and organs in our body. They are also responsible for how our body processes the food we eat.
The behavior of these proteins can change from person to person, depending on the sequence of nucleotides (A, T, C, and G) found in each of our genes. The locations where these nucleotides vary from the norm are called genetic variants.
Genetics and Nutrition
Genetic variants can have a huge impact on our bodies, changing our phenotypes. Phenotypes are the characteristics you can observe, like height or hair color, and the combination of alleles that become your genotype.
Epigenetics, on the other hand, is studying how environmental factors impact your genes’ functioning. Epigenetic changes are reversible, unlike genetic changes.
How you process nutrients is a product of your genetics as well. After all, each human being looks unique, so wouldn’t it make sense that we each have unique differences in areas like metabolism, digestion, and excretion?
The immense possibility for minute changes within our genes is why genetics has such a huge impact on our eating habits. As geneticists learn more about nutritional genomics and how our body’s metabolic system works, we can customize our diet to ensure that we’re getting all the nutrients we need.
Genetics and Our Taste Preferences
In addition to changing how our body processes, uses, and stores certain nutrients, the study of genes tells us that our genetic variants have also been linked to our individual taste preferences. Due to certain variants that can be identified through genetic testing, some people are more sensitive to tastes like bitterness and sweetness, leading them to prefer certain foods and avoid others.
For example, being more sensitive to the bitter taste of certain foods like kale and Brussels sprouts may cause people to exclude them from their diet. This could lead to an ongoing deficiency in certain nutrients if they’re not properly consumed within ones diet.
Bitterness isn’t the only basic taste that people can experience differently. There have been certain genetic variants identified that can impact the way that we perceive sweet, sour, salty, and umami flavors.
Additionally, there are even individual foods that can be perceived differently by different people depending on their genetic variants. For example, up to 14% of the global population finds that cilantro tastes like soap, while the rest love it and enjoy it in many dishes. It may not be a coincidence that many of the people with the ‘soapy cilantro’ genetic variant (formally known as OR6A2) come from countries where cilantro is not a popular addition to the local cuisine.
Is There a Link Between Genes and Food Cravings?
For the majority of human beings, eating food is an experience that’s about more than just ingesting nutrients. The sensory component of a meal cannot be denied. Despite our best efforts to follow a nutritious diet, it makes sense that our experience of food will influence our food cravings.
For example, some people crave sugar because they have genetic variants that impact the way that sugar affects certain regions of their brain, or how their body processes and controls insulin. This is an area where complex research is still ongoing.
Learn How Your Genetics Affect Nutrition
When it comes to understanding our genes and how they affect our health, there’s always more to learn. You can find out more from the National Institute of Health (NIH), the National Library of Medicine’s MedlinePlus resource, or by reading about the Human Genome Project. To learn more about your own genetics and how it affects your nutrition, you can take an at-home DNA nutrition test like the ones we offer at GenoPalate.
These nutritional DNA tests offer insight into the genetic variants that affect your health, including your eating habits and how you metabolize food. With that information, you can start your personalized nutrition journey of truly eating for your DNA.