Who doesn't love to get stoned out of their gourd? Use of intoxicants isn't even confined to our species – Egyptian fruit bats are known to get drunk on fermenting fruit. They seem aware of the potential consequences, which include the mucking up of their flying and navigational skills. This explains why some apparently avoid eating overripe fruit and why fruit bat alcoholics aren't a thing. If only we had bat brains. Some researchers even suspect that agriculture arose around 10,000 years ago as a reliable way to make beer, as opposed to a reliable way to eat. The ingredients of betel nut quid for chewing. Credit: Adam BrummThe ingredients of betel nut quid for chewing. Credit: Adam BrummWe already knew that prehistoric peoples used mind-altering substances, but now a report provides the earliest evidence of drug use yet. The skeletal remains of two hunter-gatherers in Sulawesi, Indonesia, indicate that they sucked on mind-altering betel nuts, one as long as 16,000 to 25,000 years ago. The other one was doing that 6,300 to 7,600 years ago, Adam Brumm of Australia's Griffith University and Marlon Ririmasse of the Pusat Riset Arkeologi Lingkungan research institute in Jakarta reported with an international team in Science Advances on Wednesday.Why is there such a wide margin of error on the dating for these addled hunter-gatherers? "The site has been challenging, as no charcoal for radiocarbon dating is preserved, so we had to use a combination of methods, including luminescence dating of sediments and uranium-series dating of bones, teeth and stalagmites," Brumm says. An eroded molar, presumably from compulsive sucking on betel nuts. Credit: Davd McGahanAn eroded molar, presumably from compulsive sucking on betel nuts. Credit: Davd McGahanThe Leang Cappolombo cave, where artifacts were found. Credit: Fakhri The Leang Cappolombo cave, where artifacts were found. Credit: Fakhri The smoking spliff isn't cave art portraying this horrible habit but the parlous state of the two hunter-gatherers' teeth. Both exhibited hollowed-out rounded grooves in specific molars. The archaeologists believe that this erosion was caused by the compulsive sucking on hard spherical objects – not stones but betel nuts, a thesis supported by the presence of the betel intoxicant arecoline in the hunter-gatherers' dental plaque. Also, the object clenched between the rear molars of these people was 10 to 20 millimeters (0.8 inches) in diameter, which fits betel nuts on Sulawesi, one of Indonesia's biggest islands. In any case, the wear pattern on the teeth wasn't typical of routine consumption of anything. The researchers note that betel nuts, also known as areca seeds, have no nutritional value, so they weren't being held in the mouth for that.Inferred positions of nuts based on dental wear patterns in molars. Credit: Melandri VlokInferred positions of nuts based on dental wear patterns in molars. Credit: Melandri VlokThe Leang Bulu Bettue cave. Credit: Basran Burhan and David McGahanThe Leang Bulu Bettue cave. Credit: Basran Burhan and David McGahanModern folk don't suck betel nuts, we chew them in the form of "betel quids." The quid is made by shelling the nuts and crushing or slicing their seeds, and mixing the mash or slices with calcium hydroxide (slaked lime). Sometimes the mixture is flavored with spices such as cardamom. The plain or flavored mash is wrapped in a leaf to create a quid, which is inserted into the mouth and chewed. The drug reportedly causes mild stimulation, helping you stay awake, and even mild euphoria.Regular indulgence leads to tolerance, leading the user to increase the dose, which can cultivate chemical dependence, aka addiction. Side effects of habitual quid chewing include staining your teeth and mouth red, eroding your teeth, and triggering oral or esophageal cancer. Even so, the scientists say that one in 10 people today, from Africa to Asia to Micronesia, chews betel quids. Well, almost two in 10 people today still smoke cigarettes, knowing full well how bad that is. Withdrawal from betel dependency can involve mood swings and anxiety, not to mention the wicked combo of fatigue and insomnia.A fragment from an upper jawbone at the dig. Credit: David McGahanA fragment from an upper jawbone at the dig. Credit: David McGahanAnother view of the Leang Cappolombo cave. Credit: Fakhri Another view of the Leang Cappolombo cave. Credit: Fakhri The question is when humankind began to ride the betel beast, and now we learn that in Indonesia it started possibly as long as 25,000 years ago.Inconveniently for the archaeologists, sucking the nut whole does not stain the teeth red like the modern custom of chewing betel mash in a quid with slaked lime, Brumm explains. The lime triggers a chemical reaction that turns the saliva bright red. But the hunter-gatherers didn't have crimson teeth, just damaged ones. Did holding a nut in the mouth without accessing the inner seed make these people high? Yes. Remember, today the main neuroactive alkaloid in betel nut, arecoline, is released by chewing the nut processed with slaked lime, but stick that nut in the mouth for a decent while and it releases the desired arecoline, albeit less than one would get by crushing and processing the nut, the team reported based on experimentation.So plausibly the betel habit began as simply sucking the nuts, and the common assumption that betel addiction began with the onset of agriculture was simply wrong. More artifacts from the Leang Cappolombo cave. Credit: FakhriMore artifacts from the Leang Cappolombo cave. Credit: FakhriJaw fragments supporting the researchers' thesis. Credit: Adam BrummJaw fragments supporting the researchers' thesis. Credit: Adam BrummIn any case, this is the earliest known instance of deliberate inebriation, the team says, helpfully listing known intoxicants of prehistory, as detected by archaeologists. Hitherto the earliest was beer made using barley 11,000 to 13,000 years ago in Israel. Then we have the psychedelics San Pedro cactus and Mescalbean that were used 10,400 years ago in Peru and Texas, while paleo-Indians painted pictures of psychedelic datura 10,000 years ago, and our friend the coca leaf was used 8,000 years ago in Peru. Finally, Psilocybian mushrooms were used 8,000 years ago in the Sahara.The researchers note that we have no idea when use of any of those began, let alone how the ancients discovered their delights. In short, the list and now the new discovery debunk the vague notion that intoxication began with farming. The scientists note that early betel use in some form had been suspected in certain ancient teeth, such as 13,000 years ago in Thailand, but the dates were unsure. The earliest proven betel user was also in Thailand but just 3,500 years ago. Now the timeline is much further back. So we don't know origins or prehistoric rationale, but we know what we like, and one in 10 likes betel quids. What's betel to the other 90 percent? It is the drupe fruit (which means it has flesh and a pit like a peach) of areca palm trees in tropical regions of South Asia, Southeast Asia and the wider Pacific. We do not chew on its shell; we crush its seed. In time, once we chew the quid and turn our saliva bright red, our teeth will be stained as well. Sadly, as Brumm and the team suggest, like many an addict today whose habit alleviates the pain of anticipating bad effects in the future, these ancient hunter-gatherers could have found themselves trapped in a loop of sucking on betel nuts to relieve toothache – as this habit worsened their oral health. Today's betel buffs aren't in a good place either. "Betel quids are chewed in the buccal cheek cavity, with the blood-rich tissue in this part of the mouth allowing the plant compounds to enter the bloodstream more rapidly," the team writes. This practice elevates the risk of oral cancer. The compound's absorption is facilitated by the slaked lime.When people stopped mouthing the mind-altering nut and began to convert it into chewable quids is a mystery. Maybe in the Neolithic, the scientists suggest. The researchers note that people sometimes stick stuff in their mouth and just keep it there, not for eating or anything else really – a blade of grass, for instance. But holding a betel in the oral cavity and gnawing or chewing or just sucking on it had deleterious effects, hence the sense that the behavior was compulsive, which suggests that these people were getting high.And the scientists add that skeletal remains of preagricultural foragers are extremely uncommon in southern Sulawesi. So probably the compulsion and physical dependence goes back far, far before our hunter-gatherers from 16,000 to 25,000 years ago. Who knows, maybe the inspiration behind the earliest figurative art ever found, the portrait of a warty pig on the very same island of Sulawesi from over 54,000 years ago, wasn't only the swine's charms.