I recently sat in on a short lecture on nutrigenomics as it applies to the development of new pet foods. My initial response was probably the same as the one you are having right now … nutro-g-what?
Nutrigenomics is the study of how nutrients can affect the way genes are expressed in the body. To make this a little easier to understand, below is a quick review of genetics:
DNA (deoxyribonucleic acid) is the stuff that our genes are made of. DNA is primarily found in the chromosomes contained within the nuclei of our cells. A portion of DNA that codes for a protein is called a gene. We inherit particular forms of each of our genes from our parents.
Genes are essentially information. To be put to practical use in the body, this information needs to be converted into proteins. This is done by using a gene’s DNA as a template to make RNA (ribonucleic acid), and this RNA is the template from which proteins are synthesized.
Proteins serve many roles. Some are enzymes that speed up chemical reactions. Others are hormones or serve to transport molecules around the body … the list could go on and on. Suffices to say that proteins probably play a role in every bodily function that you can think of.
Once sperm meets egg there is no changing an individual’s genetic makeup. But, because genes are really just an "encyclopedia" of information, the body can decide which passages to "read" (i.e., convert into RNA) and make use of (i.e., convert into protein). Genes can be up or down-regulated (think of the way a dimmer switch controls a light) in response to environmental stimuli, meaning that they will produce more or less of a particular protein depending on the situation.
Now back to nutrigenomics. What is the biggest environmental factor that we have direct control over in our pets’ lives? I’d argue that it is their diet. Every day we pick what nutrients our dogs and cats will ingest, and altering gene expression is one of the ways that diet has a huge effect on their well-being. For healthy individuals, my take home message from the nutrigenomics lecture was simply, "eat well." Make sure you are giving your pets high quality, nutritionally balanced foods made from healthy ingredients.
This can be taken to the next level when an animal is sick, as well. Altering the nutrient profile of a pet’s diet can be used to switch the genes that play a role in a particular illness on or off. For example, research has shown that all forms of weight loss in dogs are not equal. In one study, a group of overweight dogs was fed an "Atkins-like" diet and another was fed a diet that was low in calories but high in antioxidants and L-carnitine. Both groups lost similar amounts of weight, but only the latter diet resulted in an up-regulation of fat burning genes and a down-regulation of pro-inflammatory genes.
Stay tuned. Nutrigenomics is a new field and the results of future research should be fascinating.
Dr. Jennifer Coates