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Your Saliva Can Change How Foods Taste, Help You Eat Healthier

Proteins in our saliva could be targeted to influence how foods taste, researchers say. And this can help weaken the bitterness of certain foods, potentially helping people stick to healthy diets.

Findings of the research will be presented at the 256th National Meeting & Exposition of the American Chemical Society (ACS) on Aug. 20.

Taste can be regarded as a significant obstacle that gets in the way of a healthy diet. While foods like broccoli and dark chocolate are nutritious, they also leave a bitter taste to deal with. Meanwhile, the taste of unhealthy, fried foods can often be very hard to resist.

But could eating bitter foods regularly influence some kind of change to help people get over this aversion? Well, that is what the research team decided to test out in the new study.

"By changing your diet, you might be able to change your flavor experience of foods that at one point tasted nasty to you," said Cordelia Running, principal investigator of the study.  

As most can tell from its appearance, saliva mostly consists of water. But our salivary glands also release thousands of proteins which help bind flavors from food to taste receptor cells in the mouth.

"If we can change the expression of these proteins, maybe we can make the 'bad' flavors like bitterness and astringency weaker," said Running, who is an assistant professor at Purdue University, Indiana.

Participants were instructed to drink chocolate almond milk three times a day for a week and rate its bitterness and astringency. Their saliva samples were also collected and tested, revealing a change in the protein composition that week.

After consuming the milk, there was a noticeable increase in the levels of proline-rich proteins in the samples. These proteins help bind the bitter compounds in chocolate.

The sensory ratings provided by the participants seemed to correspond to changes in the proteins i.e. when the protein levels increased, the ratings for bitterness and astringency decreased.

Running believed the body adapts to the taste of these bitter compounds in order to reduce their negative sensation. As per the findings, saliva modifies the flavor of the food we eat, which in turn could modify our dietary choices.

"Those choices then influence exposure to flavors, which over time may stimulate altered expression of saliva proteins, and the circle begins anew," she added. "Maybe this knowledge will help someone stick to a healthier diet long enough to adapt to like it."

In future studies, Running hoped to identify the specific compounds in food which trigger changes in salivary proteins. She also wanted to measure the time taken to reduce bitterness and also investigate whether mimics for these proteins could be added to foods in order to improve their taste.