US, WASHINGTON (ORDO NEWS) — Why can most people drink alcohol? One fascinating theory is called the “Drunken Monkey,” and it boils down to the evolutionary benefits that our distant ancestors gave about 10 million years ago the ability to eat fallen fruits, even if they were already starting to roam. But not everyone in the body has the same number of enzymes responsible for the processing of alcohol.
“Everyone says that Jeppe is a bitch, but no one asks why,” such words appear in the old classic play by Ludvig Holberg, “Jeppe on the Mountain,” written back in 1722. Of course, one of the reasons, perhaps, is that his wife is beaten by Nille, who also cheats on him with a watchmaker. But in fact, a causal relationship is not always so easy to figure out.
For example, the case is probably connected with one enzyme called alcohol dehydrogenase, which is needed in order to break down alcohol and which Jeppe has. Another enzyme is needed – aldehyde dehydrogenase. Without it, drinking alcohol would not bring any pleasure. That is why the drug “Antabus” quite effectively averts people from drinking, because it prevents the development of this enzyme. If you drink “Antabus” in a therapeutic dose, then when you drink alcohol, you will have unpleasant symptoms like headache, palpitations, nausea, vomiting, and so on.
This version of alcohol dehydrogenase, according to recent discoveries and theories of scientists, appeared in our monkey-like ancestors about 10 million years ago. Mutations that remain for such a long time usually give the mind one or another advantage in terms of reproduction or survival (or both). Therefore, there is reason to believe that alcohol has been involved in our evolution for a very long time (unless, of course, this enzyme had another important function that is not related to the breakdown of alcohol, even if there is no evidence for this).
Small advantages are enough for such changes, mutations, to persist and spread in the population, as happened in people who, for example, Europe. For many Asians, the process with aldehyde dehydrogenase has not gone so far, and therefore this enzyme is often less active in them.
So what could be the advantage due to which this mutation in our monkey-like ancestors survived and spread? If you imagine that fruits were an important part of the diet of our distant relatives, it is obvious that the ability to eat easily accessible fallen fruits that have already begun to ferment was beneficial. The benefit of the mutation, which allows you to eat fruits that have begun to deteriorate, is, of course, not too great, but still significant enough if we consider it on the scale of many generations.
This is only a hypothesis that requires further evidence, but it is believable and even quite funny: it is interesting to imagine how our ancestors thought that overripe fruits can be used in a more complicated way – squeezing out delicious juice from them.
Chimpanzees and humans were evolutionarily divided between 6 and 7 million years ago. In other words, a mutation arose even earlier, which means that approximately when our ancestors just adapted to life below, on earth. These close relatives of ours, as you know, could create and use tools, and there are theories how they could use fermentation products and alcohol-containing palm juice with their help.
The “drunken monkey” hypothesis causes a lot of controversy, but it is really interesting, and I don’t know a more believable one. If true, intoxication could be a bit of a side effect, while the main evolutionary goal was to simplify the search for food for our ancestors, who are now better able to tolerate alcohol.
There is much evidence that other animals eat up something drunk, although the stories of moose and fermented hopping apples remain open to question.
But if once the ability to process alcohol, resulting from the work of evolutionary mechanisms and natural selection, was an advantage, then how are things going now? How does alcohol affect health and longevity? Of course, everyone knows that large amounts of alcohol are harmful, but where does the border go? We know a lot of bright personalities who drank a lot, but still survived to old age, maintaining clarity of mind. A famous example is Winston Churchill. How much alcohol he actually consumed is not exactly known, but he clearly did not adhere to the current recommendations. His own opinion was unequivocal: he received more from alcohol than lost.
Another prominent person who drank a lot, but remained active until a very old age, is Luigi Cornaro, who died in 1566, as they say, at the age of about one hundred years. He was an entrepreneur and tried many different activities. Thanks to distant kinship, he got out in the nobles. He lived on a grand scale and did not particularly respect morality, but at about 40 decided to change. He began to write books about his new way of life, which included, among other things, a fair amount of moderation in almost everything. He did not refuse meat, but on the whole he ate quite a bit. This limited calorie intake clearly prolongs the life of many species of animals.
Like Churchill, Cornaro wrote several of his best books over the age of 80 — for example, Conversations on the Benefits of Moderate Life, which has become very popular. Despite this moderation, he drank wine decently – much more than the maximum of 14 standard drinks of alcohol, which is now recommended by health authorities for men. They say he blew at least 20 servings, that is, about two-thirds of a bottle of wine per day.
Of course, all these are just individual cases, but what does science really say? How much can we drink without harming ourselves and so that the cons do not outweigh the subjective advantages? In humans, it is difficult to conduct controlled experiments with alcohol. As in the case of nutrition, it is impossible to carry out a double blind experiment where not only the subjects but also the researchers remain ignorant of the important details of the experiment. So compared to drug research, everything here is very complicated.
Therefore, it is not so easy to find out how much alcohol can be good for health, if there is any benefit from it. There are problems with cause and effect relationships. Because experimenting on people is difficult, researchers often rely on polls to tell people how much they drink. But in our days of endless leaks of information, we have to consider that people often do not tell the whole truth about their alcohol habits, although to some extent this can be compensated by measuring the concentration of alcohol markers in the blood.
There are studies on morbidity and ill health that indicate the presence of a so-called U-shaped curve. This means that those who do not drink at all and those who drink a lot are at the greatest risk. It is on the basis of this information that the current recommendations are based. But the problem is again in a causal relationship: perhaps today a person does not drink at all, because he used to drink too much or because he is sick, and the disease reduces his interest in alcohol. Such a problem exists within the framework of epidemiology, where they do not conduct experiments, but simply look at the statistics. Medical research is most successful with a combination of different approaches – experiments and epidemiology.
As for epidemiology, its methods have been improved in recent years. For example, researchers resort to the elegant “Mendeleev randomization.” There are different genetic variants that provide different phenotypes, that is, features, both physical and psychological. It is believed that a person receives a particular genetic variant by chance, and this can be used as a kind of verification based on origin in a randomized study – dividing people into those who have a certain genetic variant and those who do not have it. Of course, a full-fledged randomized trial still will not work, because experiments are not carried out. But this tool is being sharpened more and more, which means that the risk of confusion with a causal relationship is reduced.
This method has recently been used to study the effects of alcohol on health, based on the various variants of aldehyde dehydrogenase found in people in China, where many people do not tolerate alcohol. People with this genetic variant have become a control group: it is known that they don’t drink alcohol at all or drink very little, because they feel bad about it. With their help, it was possible to form a group of teetotalers who adhere to such a lifestyle not because they are ill or were previously alcoholics.
Scientists have proven that in this case, the U-shaped curve disappears: a complete rejection of alcohol can no longer be associated with some kind of disease and generally harm to health. But even small amounts of alcohol immediately increase the risk of getting sick with something.
Researchers concluded that alcohol is simply harmful, even in very small quantities. The idea that moderate amounts of alcohol are good for health has come under threat.
But it’s not so simple. As is usually the case in such cases, the study has weaknesses. As you know, it is impossible to bring it to its absolute completion. The weakness of the job lies in information about alcohol consumption: given how closely citizens are monitored in China, people there may not be inclined to honestly report how much they drink. True, data collection was carried out more than ten years ago.
But genes can have a pleiotropic effect, that is, they can provide more effects than originally thought. In our case, we are talking about the ability to tolerate alcohol. Perhaps the genetic option, in which a person does not tolerate alcohol, is also associated with a decrease in the risk of a disease for other reasons. In addition, the study did not study red wine, and it is with this drink that various health benefits are primarily associated.
To understand something for sure, experiments are needed. Today in medical and other natural sciences there is a tendency to skip the stage of experiments (because they require painstaking work and are expensive) and rely on mathematical models, statistics and epidemiology. But what do you tell patients if you are a doctor? In the absence of habitual scientific knowledge, one has to act in accordance with proven experience – and since antiquity it has been known that moderation in everything is useful. And perhaps it is better if your alcoholic drink is red wine, not vodka. Hippocrates also believed that “wine is an amazing thing, useful for both a healthy and a sick person, if used to the best of and taking into account the characteristics of the individual.”
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