Don't Call Me Sourpuss
Cats respond very differently to bitter tastes compared with humans, research published in BMC Neuroscience reveals.
As plant eaters, humans need bitter taste receptors, known as TAS2Rs, to detect possible plant toxins in our food. Cats also have these receptors, despite being carnivorous, to detect toxins in prey or rotten food, but they perceive bitterness very differently to us.
In people, the TAS2R38 receptor detects compounds called PTC and PROP, bitter substances sometimes found in green vegetables. If these receptors are supersensitive, that could explain your bias against broccoli or why you can't stand sprouts! In cats though, the receptor is 10 times less sensitive to PTC, and unresponsive to PROP, meaning we could include cat's five a day in their food without them stalking away.
What could cause problems though is TAS2R43. Humans know the sensitivity of this receptor to particular compounds, and take advantage of it by putting bitter triggers into household and hygiene products and medications to prevent improper ingestion. For example denatonium - 'the bitterest known compound' - is used to deter children from drinking antifreeze. Cats are actually much more sensitive to denatonium than we are, explaining why they don't always take the bait with the tasty treat you hid their medication in.
By really understanding our feline friends' taste responses, researchers are hoping to make more appealing, nutritious food for them to eat - and make the dreaded medication giving a bit easier on all involved!