Genetic Mismatches And The Terrible One-Two Punch In Our Food System
Happy New Year to all of my faithful readers out there! Although there are several ways our diets have diverged from our ancient ancestors, today, I want to especially touch upon the two primary ingredients in our food supply, causing untold havoc on our health and well-being. They are processed seed oils and carbs. Industrial seed oils account for 8 percent of our total calorie intake today, which is estimated to be 3.5 to 8 times higher than humans have ever encountered in our time on earth. (1) Additionally, humans had little or no previous evolutionary experience for processed carbohydrate consumption throughout our history; therefore, our intake of them is comparatively new considering our time on this planet as a modern species. (2)
Industrial Seed Oils
Industrial seed oils were introduced and subsequently adopted into our diets about one hundred years ago. As I spoke about in a previous post, these oils are primarily composed of omega-six varieties. The increase in consumption has caused an imbalance in the omega-six:omega-three ratio. Today, the average person consumes 10:1. Our ancestors consumed a rate closer to 2:1 or 3:1, which I and many others consider to be healthy. As a result, we now suffer from the so-called chronic diseases of modern civilization, such as heart disease, obesity, cancer, gum disease, and many others. (3) Keep in mind these problems seldom if ever occur in populations that don’t eat processed foods.
Processed Carbohydrates
Ten thousand years ago to about five thousand five hundred years ago, there was little or no previous grain consumption in the human population. Initially, relatively crude processing of grains using hand-held grinding stones resulted in less refined particles of carbohydrates, and inclusion of the bran portion of the grain. Highly refined grains using modern industrial machinery have only been widely available for about one hundred and fifty years. (4) Consumption of processed carbs causes a spike in blood sugar rarely if ever seen in our ancestors. A spike in insulin secretion follows to deal with the blood sugar level. Repeated bouts of sugar and insulin spikes lead to insulin insensitivity. Pre-diabetes is the early form of insulin insensitivity; frank type two diabetes is the latter. Diabetes causes untold suffering and medical expenditures. Other common diseases associated with insulin insensitivity and processed carbohydrate consumption are obesity, heart disease, and cavities, to name a few. You can read more about the subject of processed carbs in my previous posts here and here. As I stated in the last section, these illnesses do not exist in populations that only consume unprocessed foods.
Genetic Mismatches
Given enough generations and the selective pressure to survive a given environment, organisms will eventually adapt or go extinct. The process of adaptation happens when our genes change enough through mutation and selective pressure to cause adaptation. During the period of adaptation, our environment and the genes to handle it do not line up correctly. When genes can adequately handle the niche, no adaptation is needed. During periods of adaptation, there must always be a mismatch between the environment and our genes.
Genetic Mismatch Example
The Pronghorns of North America (commonly called Antelopes due to their resemblance to old-world antelopes) are by far the fastest animals in this hemisphere. The only animal speedier than the Pronghorn is the Cheetah. Their speed has long baffled scientists, as Pronghorns don’t require anywhere near this talent because Cheetahs don’t live in the Americas, and no other predator is remotely fast enough to catch a Pronghorn. The mystery was solved when researchers discovered that there were American Cheetahs that went extinct. The speed Pronghorns possess was needed to help them survive in past generations. Given enough time, Pronghorns may become slower animals, as there is no pressure to have to run as fast anymore.
Processed Carbohydrate Genetic Mismatch
The foods available to us as hunter-gatherers did not contain many readily available carbohydrates. One of the worst things too many carbs can do is raise our blood sugar too high. The ability of foods to raise blood sugar is called the Glycemic Load. The glycemic load of Rice Krispies and Jelly Beans is around 72, whereas grapes and yams are around 8. I want the reader to keep in mind that modern grapes and yams have been changed by humans to contain much more carbohydrates than their ancient wild types, so their glycemic load may have been around four or even less. That said, modern grapes and yams are 900% lower in glycemic load than Rice Krispies and the like. Thornburn et al. noted in their paper from 1987 that carbohydrate in traditional diets is slowly digested and absorbed and may once have been protective against diabetes. (5) Because we evolved in a low carbohydrate environment, we are genetically optimized to eat a low glycemic load diet free from processed carbohydrates.
Adaptation only cares if the individual can survive long enough to have offspring. The health effects of our high carbohydrate diets do not present until later in life in most cases. Indeed they do not interfere with fertility enough to prevent the ability to have a family so that the selective pressure may be too weak today to result in adaptation. The best thing to do in the meantime is to lay off the processed carbs. Click here for a list of foods containing processed carbs to avoid.
Industrial Seed Oils Genetic Mismatch
We cannot make Omega-6 fatty acids ourselves, and so we must consume them or perish. They are called essential for this reason. We used to get them from animal fats. The best source is fatty fish, but other meats contain them as well. Processed seed oils are mostly Omega-6 fats, but the version in vegetables is different and must be converted to the animal type, and this process is only 3% efficient in humans. The vast majority is transported in LDL particles and oxidizes, a process that leads to heart disease. (6)
Marketers have capitalized on the Omega-6 angle to push sales. Unfortunately, their success has resulted in increasing our consumption of Omega-6 fats to 8% of our total calorie intake, which is up from the 1-3% our ancestors experienced. As I mentioned in an earlier section, this has skewed the Omega-6:Omega-3 ratio to unhealthy levels, and you can read more about it in my previous post. Essentially, our bodies will use the excess Omega-6 fats to make all sorts of things ranging from mediators of inflammation to cell membranes. Using too much damages the form and function of them.
Our bodies are much like a baker who is making a cake using an incorrect recipe that calls for too much flour. The resulting treat will be too dry, and the taste will be off. In time, the baker may realize the error exists and correct it through trial and error, and the cake will improve. Our bodies are like that unfortunate baker; we are using the wrong recipe. In time, we may adapt, but again, the health consequences take many years to show up and don’t generally interfere with having children. It will take untold numbers of generations for us to adapt, if ever. In the meantime, it is best to avoid processed seed oils. Here is a short list of seed oils: Soy, Canola, Corn, Rice, cotton, sesame, walnut, flax, peanut, sunflower, safflower, grapeseed, macadamia, almond, rice bran, Crisco, and shortening.
Conclusion
Corn, soy, and wheat are ubiquitous in our food supply. The corn becomes high fructose corn syrup. The soy becomes soybean oil. The wheat becomes flour. Together, these three crops constitute up to 70% of the foods we consume today. This statistic should be more frightening to you now that you know we are not optimized for their consumption. Sadly, they are delicious, and the problems they cause take years to manifest. It is best to avoid them!