This question has been in my mind for some time, why do we love the burning although sometimes painful associated with eating chilli peppers. We know the capsaicinoids, capsaicin is the compound most well known for this effect. However, the hotness is not a taste at all but rather a sensation, so there is no association between taste buds and capsaicin.
What happens is that when capsaicinoids reach the tongue, they interact with a special type of protein (called TRPV1) located on the surface of nerve cells. This protein acts as a sensor for the cell giving it information about physical heat (like a fire above 109˚F (43˚C)), the signal will activate the nerve cell to allow it to trigger other never cells that will carry the message to the brain that has to respond the dangerous temperature.
When capsaicinoids interact with this protein it also activates the same signal thinking it is being burned even there is no real present heat.
But then knowing this, why exactly would anyone would seek out and even like this burning sensation? The answer is how our brains are wired. The capsaicinoid trick the brain into thinking it is being burned, which is a painful experience once the body senses the pain somewhere like our tongue. The brain responds by releasing another type of neurotransmitter known as endorphins, which are the body's natural way of relieving the pain, by blocking the nerve's ability to transmit pain signals. Also, the neurotransmitter responsible for reward and pleasure, dopamine, is released .
Therefore when eating large amounts of spicy foods our body triggers a sense of euphoria similar to a runner's high. Some people love it others cannot stand it, the difference in tolerance for this can be discussed in another post.
BTW, did you know? Capsaicinoids are derived from the compound vanillin, which gives vanilla its delicious taste and smell.)