Chimpanzees consume alcohol daily, study indicates

Chimpanzees consume the equivalent of half a liter of beer a day by eating ripe and fermented fruit, according to a study published on Wednesday (17) that addresses the possible reason why humans are attracted to alcohol.

The discovery supports the theory that people inherited their taste for alcohol and the ability to metabolize it from primates, even though it is toxic to humans.

The researchers collected fruits that chimpanzees eat and measured their ethanol content, which is produced when sugar ferments.

They calculated that it's as if the chimpanzees drank half a liter of beer a day, which is about 14 grams of alcohol, Aleksey Maro, lead author of the study published in the journal Science Advances, told AFP.

“It’s not an insignificant amount of alcohol, but it’s very diluted and is more associated with food,” Maro explained.

The research was carried out in the forests of Africa where these animals live.

Their results align with the "drunken ape theory," championed for over a decade by American biologist Robert Dudley, a co-author of the new study. This theory suggests that the human appreciation for alcoholic beverages was inherited from primates.

Initially, it was met with skepticism among experts. But it gained traction as studies show that some primates consume fermented fruits and, when given a choice between nectars with varying amounts of alcohol, prefer the one with the highest alcohol content.

However, the study raises questions about the biological and behavioral consequences of chronic exposure to low levels of ethanol for nonhuman primates.

Another unanswered question is whether chimpanzees actively seek out alcoholic fruits or simply eat them when they find them.

Researchers will continue studying chimpanzee alcohol consumption to learn more about the origins of human alcohol consumption and assess its risks and potential benefits, Maro said.

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