Enzymes in Saliva Help Offset Effects of Diabetes

Enzyme found to help regulate blood glucose

5 April 2012 -- Blood glucose levels following starch ingestion are influenced by genetically determined differences in salivary amylase, an enzyme that breaks down dietary starches, according to a new study in the Journal of Nutrition (April 4, 2012) by scientists from the Monell Center.

In the study, amylase activity was measured in saliva samples obtained from 48 healthy adults. Based on extremes of salivary amylase activity, two groups of seven were formed: high amylase (HA) and low amylase (LA).

Each subject drank a simplified corn starch solution and blood samples were obtained over a two-hour period afterwards. The samples were analyzed to determine blood glucose levels and insulin concentrations.

After ingesting the starch, individuals in the HA group had lower blood glucose levels relative to those in the LA group. This appears to be related to an early release of insulin by the HA individuals.

"Not all people are the same in their ability to handle starch," said senior author Paul Breslin, PhD, a sensory geneticist at Monell, in a press release. "People with higher levels of salivary amylase are able to maintain more stable blood glucose levels when consuming starch. This might ultimately lessen their risk for insulin resistance and non-insulin-dependent diabetes."

The findings are the first to demonstrate a significant metabolic role for salivary amylase in starch digestion, suggesting that this oral enzyme may contribute significantly to overall metabolic status.

Additional studies will confirm the current findings using more complex starchy foods, such as bread and pasta, the researchers noted.

New Drug-free Solution to Burning Mouth Syndrome

Mechanical salivary stimulation eases symptoms of BMS.

Chewing on a piece of silicone can ease the symptoms of burning mouth syndrome, Brazilian researchers say.

This rare chronic condition is characterized by a burning sensation or other dysesthesia in otherwise normal appearing oral mucosa. Multiple parts of the mouth can be affected, but the tongue is the most common site (glossopyrosis). Burning mouth syndrome is most often seen in postmenopausal women. Prevalence estimates have ranged from 0.7 to 15.0%, with the wide variations attributed to differences in diagnostic criteria.

As reported online November 15 in Headache, Dr. Fabricio T. A. de Souza from Universidade Federal de Minas Gerais, Belo Horizonte, and colleagues had 26 patients spend 10 minutes, three times a day, chewing on a soft three-dimensional piece of silicone. Patients with dentures were told to remove them during the treatments.

After 90 days of this regimen, patients reported significant decreases in the frequency of symptoms, the number of burning sites, and burning sensations as quantified with a visual analog score.  Three-quarters of patients with taste disturbances at baseline reported improvement with treatment, and 13 of 17 women with subjective oral dryness also reported improvement.  There were no changes in resting or stimulated salivary flows, nor in the qualitative features of the saliva (viscosity, turbidity, and staining).  There was, however, "…a significant decrease in salivary levels of total protein and an increase in TNF-alpha, which may account for the clinical effectiveness of therapy," according to the authors.

Their paper did not explain how an increase in TNF-alpha could account for the effect of treatment, and the authors have not responded to a request for comment.  The researchers did acknowledge that without a control group, it's impossible to know whether the results were influenced by a placebo or Hawthorne effect (i.e., the tendency of some people to do better just because they're participating in an experiment).