Monkeys like alcohol at low concentrations, but probably not due to the calories

September 25, 2019

Fruit-eating monkeys show a preference for concentrations of alcohol found in fermenting fruit, but do not seem to use alcohol as a source of supplementary calories, according to a study by researchers from Linköping University, Sweden, and the Universidad Veracruzana, Mexico. The findings do not support the idea that human alcoholism originated from a predilection of primates for alcohol-containing overripe fruit.

When overripe fruit is fermented by microbes, alcohol is produced. Some research has suggested that fruit-eating monkeys use this dietary ethanol as a source of supplementary calories. The researchers behind the new study, which is published in Chemical Senses, set out to test this idea.

In a first experiment performed at a field station in Mexico, the researchers presented eight spider monkeys with varying concentrations of ethanol naturally found in fermenting fruit (0.5-3 per cent) and tap water as the alternative. They found that the animals were able to detect ethanol at concentrations as low as 0.5 per cent. In comparison, the detection threshold of humans for this alcohol is 1.34 per cent. The monkeys preferred all ethanol concentrations up to 3 per cent over water.

"These results demonstrate that fruit-eating spider monkeys are extraordinarily sensitive to the taste of ethanol. We also found that they prefer this alcohol when presented at naturally occurring concentrations found in fermenting fruit", says Professor Matthias Laska at the Department of Physics, Chemistry and Biology (IFM) at Linköping University.

In a second experiment, the spider monkeys were given the choice between a sugar solution spiked with ethanol and an equally concentrated sugar solution without ethanol. Here, the animals clearly preferred the ethanol-spiked sugar solution. However, when presented with an ethanol-spiked sugar solution and a higher-concentration sugar solution without ethanol, the animals clearly preferred the pure sugar alternative, even when the sugar-ethanol mixture contained three times more calories.

A similar experiment was performed in which the spider monkeys were given the choice between puréed fruit spiked with ethanol and puréed fruit without ethanol. The tests with sugar solutions and with puréed fruit that were either spiked with ethanol or not suggest that sweetness, and thus carbohydrate content, may be more important for the preferences displayed by the spider monkeys than the calories provided by ethanol.

"The findings, therefore, do not support the idea that dietary ethanol is used by fruit-eating primates as a source of supplementary calories. Similarly, the findings do not support the idea that a predilection of non-human primates for alcohol-containing overripe fruits reflects the evolutionary origin of human alcoholism", says Matthias Laska.
Article: "Taste responsiveness of spider monkeys to dietary ethanol", Dausch Ibanez D, Hernandez Salazar LT and Laska M, (2019), Chemical Senses, published online 11 August 2019, doi: 10.1093/chemse/bjz049/5546002

Linköping University

Related Alcohol Articles from Brightsurf:

Alcohol use changed right after COVID-19 lockdown
One in four adults reported a change in alcohol use almost immediately after stay-at-home orders were issued: 14% reported drinking more alcohol and reported higher levels of stress and anxiety than those who did not drink and those whose use stayed the same.

Changes in hospitalizations for alcohol use disorder in US
Changes over nearly two decades in the rate of hospitalizations and in-hospital deaths from alcohol use disorder in the US were examined in this study.

Associations of alcohol consumption, alcohol-induced passing out with risk of dementia
The risk of future dementia associated with overall alcohol consumption and alcohol-induced loss of consciousness in a population of current drinkers was examined in this observational study with more than 131,000 adults.

New alcohol genes uncovered
Do you have what is known as problematic alcohol use?

Does estrogen influence alcohol use disorder?
A new study from researchers at the University of Illinois at Chicago shows that high estrogen levels may make alcohol more rewarding to female mice.

Sobering new data on drinking and driving: 15% of US alcohol-related motor vehicle fatalities involve alcohol under the legal limit
A new study in the American Journal of Preventive Medicine, published by Elsevier, found that motor vehicle crashes involving drivers with blood alcohol concentrations (BACs) below the legal limit of 0.08 percent accounted for 15% of alcohol-involved crash deaths in the United States.

Alcohol-induced deaths in US
National vital statistics data from 2000 to 2016 were used to examine how rates of alcohol-induced deaths (defined as those deaths due to alcohol consumption that could be avoided if alcohol weren't involved) have changed in the US and to compare the results by demographic groups including sex, race/ethnicity, age, socioeconomic status and geographic location.

Cuts in alcohol duty linked to 2000 more alcohol-related deaths in England
Government cuts to alcohol taxes have had dramatic consequences for public health, including nearly 2000 more alcohol-related deaths in England since 2012, according to new research from the University of Sheffield's School of Health and Related Research (ScHARR).

Integrated stepped alcohol treatment for people in HIV care improves both HIV & alcohol outcomes
Increasing the intensity of treatment for alcohol use disorder (AUD) over time improves alcohol-related outcomes among people with HIV, according to new clinical research supported by the National Institutes of Health.

The Lancet:Targets to reduce harmful alcohol use are likely to be missed as global alcohol intake increases
Increasing rates of alcohol use suggest that the world is not on track to achieve targets against harmful alcohol use, according to a study of 189 countries' alcohol intake between 1990-2017 and estimated intake up to 2030, published in The Lancet.

Read More: Alcohol News and Alcohol Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to