Monday, March 12, 2012


What would it be like if humans could not taste the rich, delicious goodness of a hot fudge sunday, or the warm chocolate sweetness of a chocolate chip cookie? I cannot imagine a world without tasting sweets yet much to my surprise, cats and many other carnivores can. Lions, dolphins, cats and hyenas are just a few of the many our carnivores who have lost their
ability to taste sweet food.

Recent findings, sited in the article, “Why Cats, Other Carnivores Don’t Taste Sweets” explain that genetic mutations are the cause to why carnivores are not able to taste sweets. However, it was found that omnivores, animals who chew their food, are able to taste sweet foods. Their ability to taste carbohydrates serves as a survival mechanism, yet what separates them from carnivores?

The point of this information is to better understand the complexity of taste perception. It has been known for many years that cats have not been able to taste sweets, and a study completed in 2005 explained this to be true as they possess a rare mutant not enabling their taste receptors to bind to sweet molecules. To test to see if other animals shared this same mutant, researchers from the Monell Chemical Sciences Center in Philadelphia collected data from 12 different carnivorous species testing the taste receptors for sweet, salty, sour, bitter and umami. Then using computer algorithms the researchers studied each gene within every one of the 12 species to see if it contained any sequences that would stop or prevent the proteins made to sense every taste. The researchers found that seven of the 12 species studied contained the mutant, as
they were unable to taste sweet food. The researchers also found these 7 species to only consume meat and some to swallow completely without chewing, unlike omnivores as mentioned previously. Looking more closely at the genes, researchers were able to conclude that the mutations found independently inhibited sweet receptors in different species. It seems as if the species diet is directly related to the presence of these mutants which seem to have recently evolved.

This research completed explains how much the world is constantly evolving, as species are selecting traits to best suit their living environments. With this information known, pet owners or zoo keepers can learn how to best accommodate their animals for ultimate survival and satisfaction. Through better understanding of this research it could also benefit humans with the production of better artificial sweeteners to enhance our taste.

Posted by: Tara Reynolds (3)


  1. It is interesting to note that omnivores were the only type of being that had the receptors for sweetness. Among these animals would be pigs, monkeys, bears, and of course humans. Many of these animals rely on build ups of fat for the storage of energy such as bears, who hibernate and require large amounts of fat prior to. The ability to taste carbohydrates is an incredible benefit for omnivores that would need to build up fat and store energy. This way they could tell if something they were eating were more beneficial to consume than something else. This can be seen in ice cream versus salad. Ice cream has multifold the calories of salad, which proves to be a better source of fuel.

    - Jeff Keating (2)

  2. I have to say, sometimes I wish I didn't have the ability to taste sweets! Then eating a salad would be just as enjoyable as an ice cream and I could successfully diet! But alas, the enjoyment of eating for purposes other than just sustenance is something that makes us uniquely human, and as Jeff said, stems from our need to take in ample calories to survive. I wonder, though, with the access that many humans now have to a vast array of high calorie foods without having to hunt and forage for it, will we see an evolutionary change in the foods that we taste and crave in the next few hundred or thousand years?

    Posted by Laura Moro

  3. So many new and interesting things that I've learned in this article. Fascinating to know that carnivores and cats can't taste sweet and some don't even chew their food!What caused the genetic mutation to occur, which makes these species unable to taste sweet? Is it because they hardly ate something sweet therefore the body evolved to disable the species from tasting sweet? And why only sweet? Is there other species that might not be able to perceive other tastes?

    -Hermann Kam