The consumption and production of alcohol is considered by many scientists to be a universal characteristic of mankind.
According to the hypothesis of Nobel laureate in chemistry Robert Dudley, it is the result of evolution. The human brain has formed a stable associative link between the consumption of ethanol and tasty food.
How this might have happened is shown by studies of primates and other animals. Scientists have long noticed that monkeys like over-ripe fruit. Such fruits undergo a fermentation process with the release of ethanol, which is volatile, so the smell of these fruits spreads better. This attracts the primates, and they end up getting quite a tangible dose of alcohol on a regular basis.
For example, chimpanzees from Uganda eat an average of 6 kilograms of fruit a day, getting about 14 grams of ethanol along with it. This corresponds to about 175 ml of an alcoholic drink with a strength of 10%.
And over time, people have transformed the skill of finding ripe fruit into an essential part of human culture. But it has its peculiarities, and not always ethanol becomes the reward the brain craves. Here are a few of the findings of scientists about the effects of alcohol on the brain and psyche.
A small dose of alcohol can make people more attractive
Alcohol can change not only a person's perception, but also how it is perceived by others. At least, that's what scientists have found in experiments.
In one of them people were photographed in three stages: sober, after one glass of wine and after two glasses. Another group of participants was shown the photos. The people in the pictures taken after one drink were, in most cases, rated as the most attractive. But when those who had two drinks and those who were sober were compared, the sober ones won.
The authors of the study suggest that the increase in attractiveness may be due to relaxation of facial muscles and greater smiling - exactly the effect of small doses of alcohol. But it goes away if more than 10 to 20 grams of alcohol per 70 kilograms is ingested. In such a case, thinking and coordination of movements are impaired, often unnoticed by the person himself. And it doesn't add to attractiveness.
But in fact, it is not only a glass of wine that can increase the attractiveness. Anything that promotes the production of dopamine will do - even a soft drink in good company, and a delicious meal, and watching a comedy. In general, anything that raises your mood and makes you feel more satisfied with life.
Alcohol impairs the brain's ability to detect imperfections in appearance
Alcohol reduces some analytical abilities of the brain, in particular, people start to identify asymmetry worse. Probably that is why the faces of others become more beautiful and harmonious in the eyes of the drinker.
At least, this is the conclusion reached by scientists from the University of Roehampton in London. In the experiment, some of the volunteers remained sober, and some had a glass or two of alcohol. Everyone was shown a pair of photos first: a natural face and the same face made symmetrical with the help of "Photoshop. They were asked to choose the more attractive face and then the more symmetrical one. Drunkards were much more often mistaken in estimation of symmetry and called more faces attractive.
Scientists even have a term "beer goggles": so called the phenomenon in which drunken people change their perception of the outside world. This phenomenon was researched by Australian specialists: they showed visitors to pubs and student parties pictures of strangers and asked them to evaluate their attractiveness. The respondents themselves were tested on the amount of alcohol they drank. The correlation was direct: the more people had drunk, the higher they rated the appearance of those in the photo.
By the way, the objectivity of self-appraisal suffers in drunken people, too. And inflated self-esteem is observed even in people who are sure that they drank alcohol, but in fact they drank a non-alcoholic beverage.
Alcohol impairs vision and dulls the sense of danger
Even a small amount of alcohol affects vision, which is one of the reasons why you should not drive after drinking. For example, binocular vision - the ability to see clearly with both eyes - is noticeably impaired. But other visual functions also suffer.
Spanish researchers offered young, but experienced drivers to take a test on a driving simulator. First sober, and a week later repeat the test after a cocktail of vodka and orange juice. During the experiment, the blood alcohol concentration was constantly maintained at 0.8 ppm. This is approximately 180 grams of vodka for a man weighing 80 kg and 115 grams for a woman weighing 60 kg. An important nuance: the vision of all participants was excellent.
All subjects had a significant - on average 0.26 points - deterioration of visual acuity. The pupil diameter increased by 0.7 mm, which can reduce retinal image quality. In addition, they were on average 29.4 km/h faster than the permitted speed of 120 km/h. And they were also in the oncoming lane more than necessary, performing maneuvers, more often involved in "accidents".
But apparently, these violations are associated not only with visual impairment, but also with a blunted sense of danger. In another experiment, American scientists offered volunteers to drink alcohol: 0.72 grams per 1 kg of body weight for men and 0.65 grams for women. The drinks had to be drunk in three drinks, and after each drink the participants were asked how safe it was for them to drive now.
As the concentration of alcohol in their blood increased, people rated the danger of drunk driving lower and their willingness to drive higher.
CONCLUSION NO. 4
Alcohol may reduce motivation to cooperate
An experiment was conducted in California: 128 strangers were divided into groups of 10-12 participants and asked to drink, socialize and play a game where they had to chip in for the common good.
Half of the participants actually drank alcohol and the other half drank a placebo. All subjects were given $10 each and asked to contribute what they wanted to the common fund.
Those who drank alcohol were twice as likely not to contribute a cent. Their average contribution was 32 percent less than that of those who received a placebo.
Alcohol consumption suppresses motivation to cooperate and act for the good of society, the scientists concluded. They suggested that this is because alcohol activates the neurotransmitter GABA, which inhibits the nervous system.
As a result, the perception of the person decreases the value of public goods and increases the value of personal goods. Probably the whole point is that when intoxicated it is difficult to predict the long-term consequences of one's actions - and the bonuses of social cooperation usually have to wait a long time.
Thus, American scientists have found that alcohol affects the areas of the brain that are responsible for the ability to wait for a small benefit, if after a while you can get a big one. So business decisions are also better made with a sober head.
Alcohol abuse can exacerbate depression
Drinking too much alcohol reduces a person's quality of life, research shows. But this is clear even without research: People with addiction have lower self-esteem and productivity, people begin to sleep less well, and often experience financial difficulties.
In addition, alcohol alters the process of dopamine production. Dopamine receptors are very sensitive to alcohol, so when a person drinks alcohol, they get positive emotions. But if one drinks alcohol frequently, the receptors will change and begin to respond less strongly to other things that used to bring pleasure - food, sex, hobbies or meeting with friends. But more and more stress hormones are released. As a result, it becomes increasingly difficult for a person to get positive emotions and to cope with stress. This often leads to depression.
For example, researchers from Australia interviewed 2,725 people. Participants told how often they consumed alcohol and then filled out a questionnaire on the presence of symptoms of depression. It turned out that those who had problems with alcohol were 1.89 to 2.34 times more likely to report severe symptoms of depression than people who drank infrequently. Researchers from Finland, who interviewed 2,215 people, came up with similar results. According to the study, people who suffer from depression and drink alcohol are less satisfied with life than those who suffer from depression but do not drink.
Having depression also increases the chances of becoming addicted to alcohol. Studies show that teens with symptoms of depression are highly likely to start abusing alcohol as adults. And people who try to cope with depression by using alcohol begin to drink more and more frequently. As a ten-year study of American scientists showed, 43% of people who at the start of observations drank infrequently, over time began to drink frequently or began to feel dependent on alcohol. Symptoms of depression in this case, as a rule, only increased.
It is not only in violation of dopamine production. The state of addicts is also influenced by feelings of guilt and shame, as well as the feeling of their own hopelessness. Alcohol addiction is really difficult to overcome, but still possible.
CONCLUSION NO. 6
Alcohol can lead to overeating
There is a clear correlation: the higher the concentration of alcohol in the body, the more you want to eat something high-calorie, fatty and salty. For example, chips, a burger, or French fries. Apparently, this effect is due to the fact that ethanol can induce a false sense of hunger.
Five years ago, the results of an experiment on mice were published in Nature Communication. Scientists gave the rodents ethanol for several days. And then they closely monitored how the animals' eating behavior changed: all the mice dosed with alcohol, regardless of their sex, began to eat significantly more than usual.
In the second part of the experiment, scientists studied the brains of these mice under a microscope. They found high concentrations of ethanol molecules, which they claimed were enough to activate agouti-like peptides in the brains. These are substances that play a key role in causing feelings of hunger not only in mice, but also in humans. Thus, the authors of the study concluded that the same processes can occur under the influence of alcohol in the human brain as well.
This physiological mechanism - and the fact that ethanol reduces self-control - most likely leads to the fact that people who drink regularly tend to eat more often - and less balanced - than those who do not drink at all or drink moderately. In 2001, scientists studied the eating habits of 77,600 French women and found that those who drank at least 400 ml of alcohol daily consumed on average 29.5 percent more calories than their compatriots who were indifferent to alcohol. They also had fewer fruits and vegetables in their diet. But more high-calorie foods, such as cheese and potatoes.