Darwin describes evolution as the process by which organisms acquire changes in their DNA so they can adapt to their environment. Evolution is an iterative process with no end point, where a species continuously evolves to retain the “fittest” of its individuals. But what happens if the environment changes too fast, and DNA doesn’t get enough time to adapt?
A discordance between the environment and our DNA
According to scientists the emergence of chronic diseases (e.g. diabetes and obesity) is a direct outcome of the discordance between the environment and our DNA. Our genomes (the entirety of our DNA) are scrambling to keep up with the dramatic changes of the western diet.
In the midst of processed and readily available food sources, metabolic genes that were previously advantageous are quickly turning into disease risk genes. Such is the case for a variant of the FABP2 gene. It was a genetic change that garnered us cold tolerance, which now increases our risk of type 2 diabetes.
The FABP2 gene
The FABP2 gene encodes a fat binding protein that chaperones fats in our gut. Fats have a wide range of functions in our bodies. They are used for energy, aid in the absorption of vitamins, and play a role in blood clotting and inflammation.
The activity of the FABP2 protein varies from person to person, due to DNA change in the FABP2 gene. Around 75% of Caucasians inherit the normal version of FABP2. The rest of us have an altered version of the protein known as FABP2 A54T (aka rs1799883).
The FABP2 A54T version binds and absorbs fats better. Studies show that it’s more frequent with increasing latitude (i.e. in colder climates). This is not surprising, because being able to extract and store more dietary fats, allows one to stay warm (and alive!) in cold conditions.
The ideas is that as our ancestors moved out of Africa into cooler climates, the A54T variant was retained, because it proved “fitter” when challenged with cold weather.
DNA is playing catch up
But times have changed. We now hold the power to wear shorts indoors on a frigid winter’s day, and no longer rely on food to keep us warm. Not only that, our lifestyle has changed drastically and we often have easy access to a plentiful food supply.
But the problems is, these foods are not always healthy. Much of it’s processed and is high in fats and sugars. Even some of the healthier options, like grains, are now processed and refined, so they are not as natural as they once were.
So, in the span of just ~10,000 years (which is quite short in an evolutionary time scale), we’ve managed to expose our DNA to a multitude of previously foreign foods. At the same time, the quantity and quality of this food has also changed drastically. The speed at which these transformations took place, hasn’t given our DNA a fair chance to fight back or evolve.
From good to bad
In essence, our (western) diet, which is riddled with processed foods, fatty domesticated meats and vegetable oils, has turned the fat storing capabilities of FABP2 into a risk factor for chronic diseases. The FABP2 variant is linked to increased fat and glucose levels in our blood, as well as a higher risk for type 2 diabetes and cardiovascular disease.
Interestingly, the link between type 2 diabetes varies between ethnicities. Also, exactly how this difference pertains to environmental factors (such as the cold) remains to be seen.
Type 2 diabetes is characterized by persistently high sugar levels. It’s one of the fastest growing diseases in the world. However, with current knowledge, managing and mitigating the risk of diabetes is as simple as changing diet and physical activity levels.
If you carry the FABP2 A54T variant (you can find this out with the DNA Type 2 Diabetes Test), will you take the steps to improve your diet and avoid diabetes?
