Beyond your genes: How your choices shape your destiny

We’ve all heard in our high school biology class that: eye color, hair type, even our risk for certain diseases is determined by our genes. It sounds so simple: two alleles for brown eyes, and voilà, you have brown eyes! On the other hand, if you inherit a “bad” gene, having a disease of some sort sounds unavoidable. However, in reality it isn’t quite that straightforward.

Despite what we’re taught in school, our genetic destiny isn’t set in stone. Of course, genes matter, but they’re only part of our journey. Much of what shapes our traits and health comes from a field called epigenetics.

Epigenetics is the study of how gene activity can be changed without changing the underlying DNA sequence. The term “epi” means “in addition to,” so epigenetics looks at what happens in addition to your genetic makeup. While your DNA provides the blueprint, epigenetic changes can switch genes on or off, affecting how your body reads that blueprint. These changes can be influenced by environmental factors like diet, stress, exercise, and even exposure to chemicals, or viruses. Unlike DNA mutations, epigenetic changes are reversible, meaning they aren’t permanent.

Additionally, your DNA is made of four chemical bases: A, C, G, and T. Epigenetics doesn’t change this sequence but modifies DNA in other ways. DNA methylation adds a chemical “tag” called a methyl group that can block proteins from reading certain genes, consequently turning them off. Think of it like putting a sticky note over a sentence in a book, you can’t read it anymore, even though the words haven’t changed. Histone modification changes how tightly DNA is wrapped around proteins called histones, controlling which genes are accessible and expressed.

Epigenetics is crucial even from the earliest stages of life, helping a single fertilized egg develop into different cell types like heart, brain, and muscle cells by controlling which genes are active in each cell.

Furthermore, epigenetic changes don’t just influence us, but they can sometimes affect our offspring and even grandchildren. In adults, they can contribute to diseases such as obesity, cancer, diabetes, and heart disease, often interacting with lifestyle choices like diet and exercise, and get this, it’s not limited to humans. In animals, epigenetics can determine turtle sex depending on temperature, and in plants, it can influence the growth cycle.

The big question is, which has more control over our destiny: genes, or epigenetics? Well, genetics provides the foundational blueprint, and epigenetics can fine-tune it, but both play only a small role in shaping our overall health and life outcomes. What matters most are factors outside of DNA entirely: your lifestyle, diet, environment, and even the microorganisms in your body called the exposome. These elements directly affect your: health, quality of life, and lifespan, in some cases more than either genes or epigenetic changes.

The final answer is, your DNA may influence your traits, but it doesn’t dictate your future. Epigenetics adds a layer of flexibility, showing that your environment and lifestyle choices can actively shape how your genes are expressed. Ultimately, you have far more influence over your future than your genes do.