Most mammals have taste receptors on their tongues that enable them to assess incoming tastes from their food. Humans have five: sour, bitter, salty, umami (meaty), and sweet. It’s natural to assume that our cats have a similar relationship with taste, especially the one that we seem to crave the most: sweetness.
However, new studies have shown that cats cannot taste sweetness or sugar, so even though you may be thinking that you’re giving your cat a tasty sweet treat, they cannot taste it at all! Cats are primarily meat-eaters, obligate carnivores that need animal protein in their daily diet, and this is likely the reason that they have no need for sweetness taste receptors.
With taste being such an intrinsic part of our human experience, it may be difficult to believe that cats do not have the same range of taste as we do. In this article, we take a deeper look at exactly what science says about this unique phenomenon and what it means for your cat. Let’s dive in!
Cats Cannot Taste Sweetness
A study published in 2015 shows that cats lack the specific receptors on their tongues to taste sweetness. It was conducted by the Monell Chemical Senses Center and found that one of the two genes necessary for the sweetness receptor got switched off at some point, most likely millions of years ago. This is not overly surprising, as most cat owners know that their cats would choose a bowl of chicken over a bowl of ice cream any day of the week. That said, most people assumed that it was a matter of preference rather than a lack of taste.
Since a cat’s diet consists largely of meat, with almost zero need for carbohydrates, it does make sense that they would not have developed the receptors to taste sweetness or at least lost it somewhere along the way.
How Do We Know Cats Can’t Taste Sweetness?
As with most studies, the details are rather complicated, and what led the scientists to their conclusion can be confusing.
In simple terms, most mammals have tiny taste receptors on the surfaces of their tongues, which release proteins that bind with foods as they enter the mouth. These proteins react in different ways depending on the food that we eat. Signals are sent to the brain letting it know whether something is sweet or sour.
The sweet receptor is made up of two coupled proteins that are generated by two genes, known as Tas1r2 and Tas1r3. In nature, sweet foods are somewhat rare and a sign of valuable carbohydrates, an important food source for most plant-eating mammals. Since cats have no need for carbohydrates, they lack the amino acids that make up the DNA of the Tas1r2, which would make it impossible to taste sweetness. Interestingly, this occurs in all cats, from your beloved housecat to tigers and lions.
Cats Can Still Taste Bitterness
Interestingly, even though cats eat a primarily meat-based diet, they can still taste bitterness. This is unexpected because this taste receptor is usually reserved for plants, the primary source of bitterness in nature, which cats — especially in the wild — do not each much of at all.
Most experts believe that cats evolved with this bitterness receptor to detect poison in foods, and there are a significant number of bitter compounds in nature that are toxic. That said, there are also plenty of bitter compounds in nature that are healthy, so this theory is questionable. It may also be that cats need to detect potentially toxic substances that their prey has consumed or the bodily fluids of their prey, like bile and venom, that can also be toxic.
Final Thoughts
It’s true: cats cannot taste sweetness. While we may feel sorry for felines in some way because they cannot enjoy a delicious dessert after their meaty meals, it’s probably for the best. Obesity rates among domestic cats are still growing, and more than half of domestic cats in the United States are overweight. With sugar added to the mix, it would probably be worse!
Luckily, your cat doesn’t know what they are missing out on, and a meaty meal is most likely perfectly satisfying!
Featured Image Credit: Alvydas Kucas, Shutterstock
