Genetics is still a hot topic in functional medicine, and for good reason. While one person’s DNA is 99.9% similar to the next, the difference in that 0.1% can comprise up to 3 million variations. Most of these variations (called Single Nucleotide Polymorphisms, or SNPs) don’t make any difference in terms of one’s life or health, but there are some that certainly can.

Genetic Testing

The ones we know of that matter most can be extracted from such testing as 23 & Me using outside analysis software like (free) or StrateGene (not free but more comprehensive.) Together, this data can give a comprehensive picture on how efficiently a person can eliminate toxins, how well they methylate, their propensity for neurotransmitter balance or imbalance, and more. 

The biggest danger associated with the analyses provided by these companies, as I see it, is the fear they can unwittingly induce. Analysis software links some genes with a propensity toward certain serious illnesses later in life. This can lead the “anxiously inclined” to fear what he or she might view as their certain fate.

But this is far from the truth.

How Genes Work

Think of a gene (or at least the ones reported via the companies listed) as a blueprint for a protein. By itself, it’s inert. It requires a complex dance of multiple molecules in order to transcribe the code into the protein. Furthermore, genes that actually code for proteins, like those listed, comprise only 1% of your genome. The other 99% was once thought of as “junk”; now we know that it plays an integral role in regulating which of that 1% actually gets expressed, or turned into the proteins for which they code. 

How does the organism as a whole use those regulatory genes? Even this isn’t straightforward, with a single regulatory gene for ‘on’ and another for ‘off.’ Rather, the process reads a bit like a “Choose Your Own Adventure” novel: it’s a labyrinth, with many possible alternate routes.

To make matters even more complicated, genes usually aren’t even expressed in sequence—gene rearrangement is quite common. So even once you decide whether the gene gets turned on or off, the ultimate protein produced can still vary widely.

How Regulatory Genes Work

So how do those regulatory genes make executive decisions about what gets expressed and what doesn’t?

It appears that there is a certain amount of intelligence involved, even at the cellular level—cells process information about their environment, and make decisions about gene expression accordingly.

They take into account not just their external environments, but their internal environments as well—environments that can be altered by such decisions as diet and lifestyle choices, and toxic exposures. This is what is known as epigenetics, defined as “the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.” Nearly every chronic illness you can think of has been heavily linked with epigenetic influences.

Furthermore, most chronic illnesses are not guided by a mutation in a single gene. They represent the complex interaction between multiple genes, and are therefore called polygenic. Once you introduce the influence of the environment, we take it a step further and call the condition multifactorial. This term encompasses the majority of chronic diseases

Epigenetics Can Alter Normal Genes Too

Even if your 23 & Me data (or whichever genetic analysis you prefer) does not show that you have a SNP in one of the protein-encoding genes, such as MTHFR, epigenetics can still play a role. As Dr Ben Lynch argues in his book “Dirty Genes”, even a normal gene can become “dirty” in a toxic environment, or if the body lacks the nutritional building blocks it needs for the protein to work the way it’s supposed to.

The Upshot

Most chronic illnesses are multifactorial: they are influenced not only by the complex interaction between many different genes, but the expression of each of those genes is epigenetic, and heavily dependent upon the environment.

Just having a SNP with a weak individual link to a particular illness does not mean you are doomed to contract that illness. There is, fortunately, a lot more going on.