This year's "Ig Nobel Prize" attracts people's attention. One of the most important reasons is that this year's "Chemistry Prize" was awarded to a study that everyone is very concerned about: Will Coke kill sperm? In fact, "Coke kills sperm" is one of the most influential "urban legends". I believe everyone has heard this expression more or less several times.
The rumor that coke kills sperm spread in Central and South America decades ago. People think that carbonic acid in cola can kill sperm, and the sugar in it can "detonate" sperm. After shaking, cola can be sprayed deep into the vagina, so women will use this trick to kill sperm after "making love" to avoid pregnancy (is cola very cheap in South America? )。 In 1960s, the American hard rock band Fugs had a song "Coca-Cola douches" about this.
This is indeed a whimsical idea, but it still needs scientific verification. 1985, Umpierre, Hill and Anderson from the Department of Obstetrics and Gynecology, Harvard Medical School opened the room in the laboratory to test its authenticity. They added frozen sperm to three test tubes filled with cola. After observation, a happy result came out: the number of sperm decreased; Coke can affect sperm motility. The related conclusions were published in the New England Journal of Medicine on June165438+1October 2 1.
When this assertion came out, it immediately caused an uproar. Two years later, Hong Chuanyue of Taipei Veterans General Hospital saw this paper and decided to use more detailed experiments to verify it. They used two brands and five different formulas of cola: classic, new, decaffeinated, diet and Pepsi. Through the experimental method of transmembrane migration, coke mixed with sperm was dropped on the membrane (allowing sperm to pass through), and physiological saline was placed under the membrane. An hour later, they observed that at least 70% of the sperm were still alive and could successfully cross the cell membrane without being killed by cola. This research, published in the Journal of Human Toxicology, overturns the views of American scholars. In other words, washing vagina with cola after sexual intercourse can not only achieve the purpose of contraception, but also easily cause genital infection.
Coke, as a kind of carbonated beverage (that is, adding carbon dioxide to the beverage), will also add caramel, pigment and other ingredients. Of course, it also contains some secret recipes with less than 1% of mysterious substances. It is said that this formula has been kept secret for more than 100 years, but in 2000, the European Institute of Food Science revealed that the mysterious substances include extracts, filters and dyes from wild peas, ginger, mimosa, orange leaves, coca leaves, cinnamon trees and vanilla peels. They make the taste of coke unique. Among the related ingredients, caffeine has attracted everyone's attention. Therefore, there are rumors that caffeine in cola has spermicidal effect and is not suitable for drinking. Is it true?/You don't say. /You don't say.
In 2003, Fabio Pasqualotto from Brazil studied 750 male compatriots at the annual meeting of American Reproductive Medicine, and thought that men who drank coffee had better sperm motility. Caffeine plays a key role in it. However, some scholars in the United States believe that drinking three cups of coffee a day will affect male fertility. The conclusion is inconclusive, and there is no definite public opinion at present.
In addition, don't underestimate sperm. When it is in the right place, it has tenacious vitality. Normal sperm can survive for half a day in vagina, up to 8 days in cervix, and 2 and a half days in uterus and fallopian tube. But if it is excreted, it can only be a short-lived ghost-half an hour, but if it is frozen to MINUS 10 degrees, it can live for three days.
In the face of rumors, we should have scientific ideas. You can even ignore the myth that drinking coke will kill sperm, and young men should be cautious.