Why do we eat what we eat? As obvious as it may sound, the strongest determinant, other than availability, is taste. Our reaction to taste – a range of responses from yum to yuck – is often instantaneous yet highly personalized. So we eat what we like, but why do we like what we like? And personal preferences aside, does taste really matter?For two researchers at the University of Miami Miller School of Medicine, the answer is yes.

“Taste is the unsung hero of the human sensory systems,” said Stephen D. Roper, PhD. “We take the sense of taste for granted because it is so stable and reliable. There are relatively few taste–related disorders and diseases, compared with the visual or auditory systems, so we pay less attention to our taste buds than to our eyes or ears. Yet the sense of taste is absolutely essential for living.”Roper and his colleague Nirupa Chaudhari, PhD – both are professors of physiology and biophysics, and otolaryngology, and faculty members in the Miller School’s Program in Neuroscience – recently co–authored a review article, “Taste buds: cells, signals and synapses,” in the journal Nature Reviews: Neuroscience that described the advances over the past decade in our understanding of our least–understood sensory system.

The journal’s editor asked them to write the article because their laboratories have often been on the front lines of the field’s research. For instance, restaurants have been touting “umami” flavor – a brothy or meaty taste that is commonly added to some foods in the form of monosodium glutamate – for the past decade. Roper and Chaudhari were the first researchers to document a molecular receptor in taste buds that is responsible for detecting umami taste compounds. The finding was key to bringing umami into the mainstream.

Chaudhari commented on three of the most important findings reviewed in the article:

1. There is specialization among taste bud cells.“We have known for years that our eyes have different cells that detect either dim light or color and bright light. Steve and I helped establish the parallel for taste buds — that we have different, specialized cells that detect sour vs. sweet taste compounds – and we have done quite a bit of work deciphering how the different cell types do their jobs.”
2. Taste buds are like tiny computers.“Individual cells detect food chemicals, and the bud then processes this information locally to encode the signals that are sent up to the brain. When they arrive, they are interpreted to produce perceptions such as ‘sweet’ or ‘salty.’”
3. We inherit some of our likes and dislikes.“Our food preferences have certain genetic origins, particularly the genes for taste receptors in taste buds. Different people have different variants of these genes. If someone has a receptor variant that produces a very strong response to a bitter compound, he or she may avoid foods containing that compound. The trouble is that there are valuable therapeutic, including anti–cancer, compounds in many bitter vegetables. In addition, patients can be non–compliant with medicines that have a bitter after–taste. So learning how to block bitter tastes is a goal that has major health implications.”Not all of our taste preferences are genetic, however. We begin developing them as infants through experience and observation, starting with breast–feeding.

“A major direction we are currently pursuing is how taste bud cells and nerves talk to each other,” said Chaudhari. “The continuing mystery is that taste bud cells live short lives and die, to be replaced by new cells. The nerves that they connect with, however, last a lifetime. So how do the taste bud cells and nerves find and recognize one another correctly?”