Genetics and diabetes: diabetes gene, the survival gene
f you have diabetes, you might have wondered why you have this condition after all. Did I inherited diabetes from my parents? The answer is yes and no. If you have diabetes type I the answer is yes; but if you have type II then the lines are blurry. Genetics lifestyle walk hand in hand when it comes to diabetes. If you carry one type of gene you’ll have a tendency to become diabetic but diet and activity might plays a larger role whether you’ll become diabetic or not.
To understand diabetes we first need to understand that diet affect people differently. Diet affect us also in the long run through generations. Our bodies may absorb some nutrients differently; some individuals may absorb nutrients well other not so well. The reasons are all in the programming created thousands of years ago by our ancestry. The only changes we can make are how we affect this process in the way we live our lives today.
All scientists agree that lifestyle is the greatest factor influencing weather you’ll have diabetes or not. Genetics is only a part of the process. Genetic propensity only means that you might have more chances of becoming diabetic. The genes which are supposedly responsible for giving you diabetes are actually a survival gene. Without it we wouldn’t be here. The story about the diabetic gene is simply fascinating.
The genetics of diabetes
There are altogether 36 identified genes related to diabetes. These genes contribute to the risk of getting diabetes. Some of these genes are related to obesity, others are related to the ability to produce glycogen (glucose ready to use when you are no eating). These genes are responsible for many functions including some of which have helped us to survive challenging times. Even though we no longer have these food challenging times our bodies are still adapted to – those challenging times.
We have lived in this planet for millions of years. Only a few hundred years ago food became abundant. After entering the industrialized era and most significantly the oil era, we begun to eat food abundance. Food in the past was difficult to obtain; you needed to work really hard to get it. The emergence of diabetes coincides with over abundance of food and migration of native peoples from the places they always lived. Diabetes was even more evident in native peoples who had a drastic change in diet and lifestyle.
One recent example example of a diabetes epidemic associated with the “food gene” happened in the remote Pacific island of Nauru. Starvation and periods of famine were common in this island were agriculture was difficult due to harsh and poor soils. Even though they were poor and had little to eat they were not skinny which is an interesting phenomena also tied with genetics (more on that later). In 1922 phosphate rock, a prized fertilizer was discovered in the island. Soon mining begun and brought lots of royalties to the islanders making them extremely rich in a short amount of time. With the money came major lifestyle changes. Instead of fishing and farming they became sedentary and could now buy food in stores. By 1950 diabetes type II exploded when it was basically non-existent. Two out of three adults had diabetic over the age of 55 and it became a common cause of death. In this case the labeled “thrifty gene” may account for what happened to the people of Nauru as their lifestyle change.
The Thrifty gene: food and physical activity connection
Thrifty gene is the name given to this one presumed gene some of us have. This gene has a direct link to our native ancestry. This goes way back 50,000 – 10,000 B.C. when man hunted 3 – 4 days out of the week and woman gathered fruits and nuts 2 – 3 days. Physical activity was part of daily life; without hard physical activity there was no life. Food was only possible after hard work, so human survival and body metabolic functions where linked with physical activity. Men must have hunted hungry but at the same time they needed the energy to hunt; the thrifty gene might have allowed for them to do just that. There were also periodical times of famine due to unsuccessful hunting, droughts, or harsh winters. There had to be a mechanism which made early man adapt to these harsh times. The thrifty gene was able to conserve energy by preserving glycogen stores by oxidizing grater quantities of fatty acids and maximizing survival during times of famine. So what we call diabetic gene was not a bad gene at all. The problem is that we no longer had periods of less food and no longer needed to work our hard with our bodies.
How the thrifty gene works
The gene selection system is very simple: whoever survives has more of a chance to pass their genetic makeup to future generations. The thrifty gene is here today because it has allowed groups of people to survive. It is a survival of the fittest gene. Thrifty genes regulates two major sources of fuel storage in humans: glycogen and triglyceride. These genes were very efficient in using and storing muscle glycogen during strenuous exercises. This may account for why people from the Nauru island were hefty; even even though they had little food at times. They were able to store energy in their muscle during famine thanks to the thrifty gene.
Diabetes have been noted in groups which were exposed to periods of famine in the past and now are living dramatically different lifestyles with a never ending abundance of fast carbohydrates.
Today food is available 24/7. Instead of having to hunt for it we have it delivered to us or can easily get it at the nearest supermarket. We no longer have to perform any exercise (unless we go to a gym), the machines and power engines do all the work for us. Not only we have a abundance of all kinds of foods, we have stripped them or their outer shell disposing their natural fibers and minerals and the best nutrients found in grains. We eat a low carbohydrate diet poor in nutrients. Our body needs remains however, linked to our genetic past which remains unchanged. Glucose storage and consumption are excessive and out of quilt with our energy needs. The result is a dysfunction of all our energy/storage regulation mechanism leading to several diseases known as metabolic syndrome and diabetes.
A video presentation of the basic concepts of the thrifty gene theory. A look into the Pima People and their relationship to the gene and diabetes
Research suggests that risk for type 2 diabetes in some people may have begun very early in life, as a result of differences in how nutrients were reaching the developing baby. Differences in nutrition, either too few or too many calories, differences in the types of foods eaten, or differences in how the placenta and umbilical cord functions to deliver nutrition to the baby, can all increase babies’ risk for developing type 2 diabetes much later in life.
- The Genetic Landscape of Diabetes
- Genomics, Type 2 Diabetes, and Obesity
- The Metabolic Syndrome: Time for a Critical Appraisal
- Review article: diabetes, genetics and ethnicity
- Genetics of Diabetes and Its Complications
- Genetics and Diabetes