Chapter 12 Chapter 10 Gene Tolerance

How much are we influenced by the environment, and how much is the proportion of genes?Discussions about unknown syndromes cannot avoid this long-debated issue.The truth is, our genes are now overwhelmed, while our environment is changing almost daily According to new scientific speculation, from low-level primitive, single-celled organisms that cannot think, to today's human beings with intelligence, emotion and civilization, biological evolution has experienced four billion years.Three or four million years ago, our ancestors who lived in the tropical jungles of Africa finally made up their minds not to keep company with the apes, but to come to the ground to open up their own living space.It took another two million years for our distant relatives, Homo habilis, to appear on the stage of history, and they were able to make stone tools.Paleoanthropologists are still debating whether Homo habilis first started hunting, or their descendant Homo erectus, who lived 1.6 million years later.It took another 1.55 million years for our direct ancestor, Homo sapiens, to arrive.Compared with the entire long evolutionary history, the last 50,000 years are like a snap of the fingers.

Famous geneticist, James of the University of Michigan.Using the latest technology, James Neel compared the genetic codes of today's humans and chimpanzees.The result is surprising, the number of genetic information carriers in chimpanzees and humans is only one.six%!It's hard to believe how close we are to apes! We are basically the same genetically as our Stone Age ancestors, and Professor Neil is not alone in believing this.This means that our genetic genes today are the survival advantages formed by adapting to the primitive natural environment at that time during the evolution process of superior and inferior over millions of years.Today in AD 2000, we carry the same genes as our ancestors 50,000 years ago.These genes gave them the best basis for survival at the time.Although, the development of genes always strives to adapt to the environment, but this transformation often takes millions of years.Naturally, this wasn't much of a problem before, when our ancestors just wandered the jungle year after year.But in the past few hundred years, the environment in which we live has undergone tremendous changes at an alarming rate.No gene development in the world can keep up with this speed.

Although we say that Adam and Eve lived in heaven, I believe that the life of the first ancestors of mankind was no better than ours today.Human beings living in modern society have to deal with long car queues, construction jungles, and all kinds of traps and fierce beasts in the shopping malls every day.The main enemies our ancestors faced were microbes and viruses.Of course, there are real poisonous insects and beasts, but with human intelligence, it is not difficult to avoid them. Long after Adam and Eve were expelled from the Garden of Eden, about 2.5 million years ago, not only were apples hard to find, but other foods were also becoming scarcer.The climate is getting colder and colder, so that the fruits of plants cannot be seen. The ice age has come, and the climate is getting drier.In order to survive, our ancestors could only eat whatever grew on the ground.There are seasons when nothing grows, or even if it grows a little, and there are other hungry animals, usually more swift and sharper teeth.So be careful at all times so as not to become a feast for other animals.

As a result, our ancestors had to suffer from hunger often.It's really not paradise to be hungry all the time, looking for food all the time, and have to be careful not to be eaten.And no one knows when the next time they will be able to fill their stomachs again.Underground pantries hadn't been invented then, and the only storage was the little bits of fat that had accumulated in the buttocks.Depending on the amount of fat accumulated, some people can last longer when starving, while others can last less.When there is a lack of food, not only the stored fat is consumed, but also the muscles are cut to provide energy, which is very unfavorable for hunting and gathering.

It is no accident that our bodies burn fat in the same proportion as muscle, which improves our chances of survival.If we only consume one of fat and protein, we will quickly deplete this substance needed to maintain life, and we will be closer to death one step earlier.The more fat on the ribs, the longer you can survive, because the consumption of fat can effectively delay the fatal loss of protein. Because fat plays such a key role in the struggle for survival, over hundreds of thousands of years, a result was naturally formed: who can accumulate a large amount of reserves, lose less weight and body composition during starvation, and in the environment at that time, The survivability is stronger.Gerald Jerome of Stanford University who named the unknown syndrome.Professor Li Wen is convinced that maintaining muscle strength during the starvation period is a decisive factor.He explained: "If you and I are two cave dwellers, and you stupidly reduce your muscle mass, when a deer runs past us, or a beast is chasing us, you probably fail. I am the winner, because I have muscles, but you have no strength to catch the prey, or escape.

Over the long years, those of our ancestors who tended to accumulate subcutaneous fat gradually replaced those thin people who were easy to be dragged down by hunger.The latter are not only unable to resist all kinds of enemies in nature due to their weak body, but also have poor reproductive ability, so they cannot pass on their genes to the next generation.That's why so many people today tend to put on a few pounds over the Christmas holidays and never lose them again.In the biological genetic software in our body, there is no program for losing weight. The phenomenon I have described above is called thrifty genotype in technical terms and hoarding storage mode in general terms (see Chapter 9).This special genetic trait is a survival advantage in the era of food scarcity, but today, the natural environment we live in has changed beyond recognition. Human beings can have a full meal at any time for 34 hours, which has become a bad thing instead.

There is no doubt that this theory is basically correct, but there are many doubts about the details.For example, it is used to explain why certain ethnic groups have serious obesity problems and a particularly high incidence of diabetes under the current Western lifestyle.The most famous example is the Pima Indians living in Arizona, USA.Anyone who has been to this area is familiar with this picture, where fat Indians can be seen everywhere with Coca-Cola (probably mixed with spirits) in one hand and snacks such as hot dogs in the other.One out of every two Pima people over the age of 30 has type 2 diabetes.Twenty-five years ago, fat people were extremely rare in this tribe, and diabetics were even rarer.

For hundreds of years, the Pima Indians have lived on the banks of the Gila River, hunting and growing some crops for a living.At the end of the nineteenth century, the white people drove them out of their homes step by step, and the turning point of fate began from then on.The Pima, who live near Phoenix today, are mainly engaged in sedentary work. Proponents of genotype-sparing theory are convinced that the Pima Indians and other peoples with very high rates of insulin resistance, such as the Nauruans of the Polynesian Islands and the Aboriginal Australians, are due to particular genetics that have only recently been impacted due to.A survey of Australians of different races with an average age of 34 years and a body mass index of 27 showed that 60% of the aborigines had insulin resistance, while only 20% of the white immigrants.

At present, we have found a relative gene variant, which proves that insulin resistance can be inherited.Why is this deadly genetic variant spreading so widely and passed down from generation to generation?This suggests that insulin resistance was once a survival advantage.What is its significance?Before answering this question, let's review how insulin works in the body. Let's imagine what would happen if we hadn't eaten for a few days?First of all, the sugar stored in our body is gradually depleted, but the nervous system still needs sugar. In order to continue to receive nutrients for the brain, an organ that is particularly important for survival, the body must find another way.Muscle is then broken down to obtain protein, which is then remade into glucose through a special metabolic process called Gluconeogenesis.Atrophied muscles are no good in an environment full of enemies.

This is where insulin resistance kicks in, causing cells to keep glucose out, preventing sugar from leaving the bloodstream and inhibiting the conversion of sugar into energy in the muscles.At the same time, insulin resistance prompts cells to burn fat for energy, muscles are forced to use fat for work, and precious sugar is saved to supply the brain.It is no accident that brain cells are the only cells that absorb sugar without insulin, and that insulin resistance does not develop. In order to keep us alive, the Creator has his own way.What's more, experts have shown that insulin-resistant animals outlive their healthy counterparts in conditions of extreme food deprivation.Likewise, insulin resistance is beneficial in injured persons, post-blood poisoning patients, and pregnant women.This directs the sugar not to the muscles, but directly to the nervous system or placenta.These clever tricks of the body have undoubtedly been perfected by evolution and passed on in the best way to future generations.Our ancestors certainly could not have imagined that their descendants would one day face a completely different living environment.

In recent centuries, human beings have established a way of life that is contrary to their genes.We have built a material paradise of life in accordance with the dream of supremacy of pleasure.No exercise, but plenty of food all the time, but it's all stuff that shouldn't be eaten.This phenomenon can be summed up as a slogan Try to try our genetic tolerance.As a result, many survival advantages in ancient times suddenly became disadvantages.Fat people in the past had stronger vitality, but today's fat people die from the same physiological mechanism.Gerald.Experts such as Li Wen believe that genotype saving is the genetic factor that humans have been looking for for a long time, leading to insulin resistance and then diabetes. I have to admit that this theory has a big flaw, that is, it does not fit the situation of Europeans.The inhabitants of this continent have not experienced starvation for thousands of years and cannot imagine that insulin resistance has not brought them benefits.Why is genotype saving not common here?Why are Europeans relatively less insulin resistant than people in other parts of the world? In fact, there is a solid explanation, which we discuss in detail in the next chapter.Before doing so, I would like to introduce a new and hotly debated topic that opens up the possibility of insulin resistance and diabetes from a new perspective Insulin resistance and diabetes triggered by inflammation. Professor Fernandez-Real of the Department of Diabetes and Nutrition at the University of Girona in Spain and other proponents of this theory believe that, in addition to bone and muscle damage, bacteria, viruses and other parasites caused by infection, was the most serious threat to our ancestors.In fact, until the beginning of the last century, most people in the world died from diseases caused by infections.In the Stone Age, it was necessary to be highly resistant in this regard in order to survive. Every infection or injury activates our immune system.In order to fight the invasion, the immune system makes the living conditions of the uninvited guests worse or directly kills them by suddenly changing the metabolic state and raising the body temperature.During this process, the immune system also produces antibodies, and even specialized antibody cells.Antibody cells use hyperactive oxygen to attack and destroy invading enemies.If there is no comprehensive nutritional intake, resistance will go wrong.People who are undernourished or incomplete can hardly resist infectious diseases, and even wounds cannot heal smoothly. In the age of drinking blood, our ancestors often went hungry.When everyone is not full to eat, those of the same kind who have an empty stomach but can still maintain their resistance are easier to survive.In the evolutionary process of winning and losing, a class of people with particularly strong resistance was formed, because it was undoubtedly a survival advantage under the circumstances at that time. For a long time, people have noticed that people with insulin resistance, in addition to high blood sugar, high blood fat and low high-density lipoprotein cholesterol, also have a tendency to clot easily, and the clot is not easy to dissolve.In addition, in their blood, the concentration of some typical antibody cells is high for a long time, which will appear after acute infection.These cells include interleukin-1, interleukin-6, tumor necrosis factor α (TNF, Tumor-uecrosisfactor), C-reactive protein (CRP, C-reaiveprotein), etc., and all of them are related to the metabolic system. have intricate relationships. Take tumor necrosis factor α as an example. It is already known that if it reaches a certain density in the body, it will promote the secretion of steroid hormones (cortisol), hinder the nutrients needed for fat metabolism, and weaken the ability of muscle cell membranes to absorb nutrients. Insulin signaling, which inhibits the entry of sugar into cells.These eventually lead to the development of insulin resistance and hyperinsulinemia. The tendency of blood clotting, high blood fat, high blood pressure and excessive steroid hormones are all risk factors that lead to the deposition of the inner wall of blood vessels, arteriosclerosis, and then cause myocardial infarction and cerebrovascular infarction.We can imagine that during the Stone Age, in order to fight infection more effectively, genes for insulin resistance were developed with the help of antibodies.Our ancestors thought of strengthening the immune system in the face of constant carbohydrate shortages, which is an advantage in every sense of the word.At that time, the average human life expectancy was estimated to be only thirty-five years, so our ancestors were not able to appreciate the shortcomings of this biological strategy. Today, the average life expectancy of human beings is approaching eighty years old. With life-saving antibiotics, when we are old, we mainly face the diseases of organ aging.The genetic resistance to inflammation is now a bit of a disaster in our material paradise.