Nutrigenomics: The Fundamentals

If you're looking for a place to start, this is it. This is your quick guide to the most important nutrigenomics terms and concepts I'll be using throughout my posts.

ESSENTIAL DEFINITIONS

Epigenetics: The study of DNA modifications that change the way our genes are expressed as opposed to those that change the genetic code itself. It is the science of how our “good” and “bad” genes are “turned on” or “turned off” determining our level of wellbeing on a daily basis.

Bottom line: Epigenetics is now being referred to as lifestyle genetics – it studies those DNA modifications that are caused and influenced by age, environment, diet, exercise habits, and disease states, among others.

Nutrigenomics: The study of the effects of nutrients on the genome, the proteome, and the metabolome – aka how our food influences our DNA, our proteins, and our metabolism.

Let’s totally switch gears for a minute and focus on some sewing terms – weird, I know. Chances are, you probably know what a spool of thread is but did you know that the wooden or plastic part in the middle – the part that the thread is physically wrapped around – has a name? This is called the winder. What does this have any to do with science, genetics, or nutrition? Let me explain...

Using this analogy, I am going to define some key genetics terms at the most basic level:

DNA = The thread

Histone = The winder in which the thread (DNA, in this case) is wrapped around.

Nucleosomes = The spool of thread as a whole

Chromatin = Your grandma’s thread box containing all of her brightly colored spools

Methylation: Methylation is the process by which specific biochemical “tags” known as methyl groups (CH3) are added to certain parts of DNA molecules. When methylation occurs, our nucleosomes tend to be more compact. The genetic thread is now more tightly wound around its histone core, preventing proteins from accessing and expressing your DNA. With this in mind methylation, at its most basic level, is often inhibitory, meaning it prevents, decreases, or downregulates the expression of genes.

Bottom line: When certain foods, nutrients, chemicals, etc. promote methylation, the expression of certain genes are likely going to be turned off.

Histone Acetylation: A type of reaction that introduces a specific chemical compound known as an acetyl group to histones - our genetic winders if you will - effectively altering the accessibility of DNA. Acetylation ultimately causes our DNA to be wrapped more loosely, allowing more of it to be exposed. In doing so, proteins involved in expressing DNA are now better able to bind to this newly exposed thread, ultimately enhancing gene expression.

Bottom line: When certain foods, nutrients, chemicals, etc. promote histone acetylation, certain genes are likely going to be expressed more.

Feel free to refer back to this resource when reading future posts...chances are, if I'm writing out a nutrigenomics-related topic, I'll most likely be using some of these essential terms described above!