The umami taste could have an important and beneficial role in overall and oral health, according to research published in the journal Flavour (January 26, 2015).
The taste quality of umami is recognized as a fifth taste category with sweet, sour, salty, and bitter being the other four. Umami is not often clinically assessed, so information about umami taste disorders has yet to be accumulated, noted researchers from Tohoku University Graduate School of Dentistry in Japan.
They conducted a study of 44 elderly patients and found that, while 16% of the patients showed a higher recognition threshold only for the umami taste, the recognition thresholds for the other four basic tastes were all within the normal range.
All patients with an umami-specific taste disorder were older than 65 years and all complained of appetite and weight loss with resultant poor overall health.
Taste dysfunction, in particular loss of umami taste, can have a negative effect on health because of appetite and weight loss, the authors noted. Taste function and salivation are closely related to each other.
The researchers used Japanese Kobucha (kelp tea, which is made of powdered tangle seaweed) to stimulate umami taste and promote reflexive salivation. Improvements were noted in salivation, taste function, appetite, weight, and overall health.
"The sense of umami taste promotes salivary secretion, and saliva strongly influences oral functions such as taste sensation," they wrote. "Thus, umami taste function seems to play an important role in the maintenance of oral and overall health."
The article is part of the journal's special series of articles "The Science of Taste."