Saliva may play a key role in determining what we like to eat, suggests a new study.
Researchers found that salivary proteins could be part of a ‘feedback loop’ that influences how food tastes to people – and by extension, what foods we’re willing to eat.
Eating bitter foods such as broccoli, brussel sprouts and dark chocolate regularly makes your saliva adapt to make them taste better.
Researchers found consuming fruit and veg increased proteins in saliva that suppressed their bitter flavours within a week.
Study leader Assistant Professor Cordelia Running, of Purdue University in the Inited States, said: “By changing your diet, you might be able to change your flavour experience of foods that at one point tasted nasty to you.
”Those choices then influence exposure to flavours, which over time may stimulate altered expression of saliva proteins, and the circle begins anew.
“Maybe this knowledge will help someone stick to a healthier diet long enough to adapt to like it.
“We think the body adapts to reduce the negative sensation of these bitter compounds.
“If we can change the expression of these proteins, maybe we can make the ‘bad’ flavours like bitterness and astringency weaker.”
Salivary glands release thousands of proteins into saliva to help digest food.
Dr Running conducted her research after similar results were shown with lab rats hoping that it could show people can overcome their hatred for healthy food.
People participating in the study drank chocolate almond milk three times per week and rated its bitterness and astringency – the dry feeling in the tongue often felt after drinking red wine.
Her team found that the protein composition of their saliva changed during that week.
Several prolinerich proteins, which can bind the chemicals that cause the bitter and dry flavours in chocolate, increased after drinking the milk.
As these proteins went up, the participants’ ratings for the milk’s bitterness and astringency reduced.
Dr Running now plans to investigate which chemicals in food create changes in salivary proteins.
She suspects bitter-tasting polyphenols in chocolate could affect salivary proteins when consumed above a fixed concentration.
Dr Running also hopes to find chemicals mimicking the proteins that reduce bitter-flavours that can be made into food flavouring.
She said: “A host of potential flavour binding proteins in saliva have been identified for decades.
“Yet, how flavour exposure or dietary patterns might alter the longer term dynamics of human salivary protein expression remains relatively unexplored.
“Through these experiments, we are discovering that many of the previously identified binding proteins in saliva may be modifiable by exposure to their flavour ligands.
“Furthermore, dietary choices such as fruit and vegetable consumption may alter expression of salivary proteins potentially linked to texture perception, inflammatory response, and enzymatic activity in the mouth.
The findings are due to be presented at the annual meeting of the American Chemical Society in Boston.