14 DAY TRIAL // After you get drunk to the bone, you are surely craving for sweets the next day.
Well, researchers led by Francisco Sanchez from the Ben-Gurion University of the Negev (Israel) remained open-mouthed when they found that Egyptian fruit bats, close but smaller relatives of the huge flying foxes, also crave for specific sugar types to decrease the effects of ethanol toxicity.
The concentration of ethanol (the alcohol molecule found in any booze, from wine and beer to whiskey) increases in fleshy fruits, like figs and dates, as they ripen.
But the Egyptian fruit bats prefer these fruits as ripe as possible because they contain the highest amount of energy and are softer (these bats do not swallow the whole fruits, but chew them, engulf the sweet juice and spit off the remaining pulp).
It may be good on one side, but the high alcohol level (roughly 1%) is harmful to the animals.
Intoxicated bats, like humans, may also get a slower reacting time, which makes them more prone to become dinner for predators or could not avoid obstacles.
The fructose, a sugar molecule abundant in sweet fruits, is known to decrease the toxicity of ethanol.
That's why scientists looked on the effect of ingesting fructose on ethanol toxicity in Egyptian fruit bats, and if the fruit bats preferred food rich in sucrose (the sugar molecule found in the common table sugar, extracted from sugar cane or sugar beet) after a high intake of alcohol.
They discovered that ethanol levels detected in fruit bats' breath decreased faster after feeding on fructose-containing food, than when the food was rich in sucrose or glucose (the main type of sugar employed by cells in burnings, which have to turn even the fructose and sucrose into glucose).
Moreover, when the ethanol level in food rose, the fruit bats preferred food rich in fructose over glucose-rich aliments.
Surprisingly, the fruit bats chose food rich in sucrose (formed by a molecule of fructose and one of glucose) above either of the other two sugars.
Even if just the fructose decreased alcohol toxicity for Egyptian fruit bats, they perceived both fructose and sucrose as good.
"We think that this observation may be due to a matter of taste or flavor", explained Sanchez.
"The perception of sweetness versus bitterness may vary according the type of sugar and the amount of ethanol consumed. The combination of sucrose and ethanol may just have tasted better than either ethanol and fructose, or ethanol and glucose".