The Relationship between Plaque pH and Glycemic Index of Various Breads

Abstract

Plaque pH was studied during 60 min in situ in 10 subjects after eating various breads. The pH response was then compared to glycemic index (GI; calculated from the incremental blood glucose area) obtained from our earlier investigations. The following four products were tested: (1) barley kernel bread (BKB), (2) BKB, sourdough–fermented (BKBS), (3) white wheat bread (WWB), and (4) syrup–sweetened wheat–rye bread (SWRB). BKB was also tested with more intensive chewing and SWRB with the addition of fat. A 5% sucrose solution served as a control. The pH drops with all the breads were considerably smaller than with the sucrose solution during the first 15 min. From 30 min and onwards the breads gave similar, or even lower (SWRB) pH than sucrose. There was a great difference in pH response among the four breads, with the most pronounced pH fall for SWRB, followed by WWB (based on the AUC values). Intensive chewing of BKB increased, while the addition of fat to SWRB reduced the pH fall, in both cases by about 0.2 pH units. A high correlation (r = 0.94) between plaque pH and GI was found, i.e. the more pronounced the pH drop in plaque, the higher the GI in blood. Therefore, both from a cariogenic and from a metabolic point of view, breads with a low GI should be recommended.

The Impact of Carbohydrate Quality on Dental Plaque pH: Does the Glycemic Index of Starchy Foods Matter for Dental Health?

“…The two different carbohydrate doses, 25 g or 50 g of glucose sugar (10% and 20% solutions) produced similar maximum decreases in plaque pH and consistent overall plaque pH excursions over 62 min. Published data have not typically controlled the carbohydrate test portion either within or between studies, with test portions varying from as low as 2 g up to 25 g of carbohydrate, limiting assessment of the cariogenic potential of different carbohydrate foods between studies [7,10,14,[16][17][18]. Furthermore, carbohydrate test portions used in previous studies may not represent realistic amounts of foods typically consumed, for example 10 mL yoghurt [27], 10 g breakfast cereal [13], or 15 mL soft drink [7], potentially restricting the real-world translation and applicability of results.…”

“…Studies examining the potential impact of starchy carbohydrates on dental caries risk are more limited. In previous studies, different breads were found to produce variable decreases in plaque pH [16][17][18] and it has been hypothesized that they may contribute to higher dental caries risk. However, methodological variations amongst studies, in particular the amount of carbohydrate tested and the assessment method for plaque pH drop, restricts comparison and interpretation of results between studies.…”

Do glycemic index and glycemic load of diet contribute to early childhood caries in preschool children?

“…In addition, the lack of the association between dmft/dmfs scores and GI/GL may be linked to the inclusion of the healthy children only because the GI may have a greater impact on patients with diabetes (Rizkalla et al , 2002). Lingström et al (2000) determined the effect of different breads on plaque pH and showed that low-GI bread resulted in less reduction in dental plaque pH than higher GI breads indicating that low-GI bread was less cariogenic. Atkinson et al (2021) investigated the effect of different starchy foods varying in their GI on acute changes in dental plaque pH and found that higher GI starchy foods produced more significant acute plaque pH decreases and larger overall postprandial glucose responses compared to lower GI starchy foods (white bread compared with canned chickpeas: −1.5 versus −0.7 pH units, p = 0.001, and 99 ± 8 mmol/L min versus 47 ± 7 mmol/L min, p = 0.026) as such higher GI foods may pose an increased the risk of dental caries.…”

“…Studies that examined the association between starchy carbohydrates and dental caries risk showed that processed starches were associated with cariogenic activity (Hancock et al, 2020). For instance, in previous studies, different types of bread caused decreases in plaque pH, indicating a contribution to higher dental caries risk (Lingström et al, 2000;Lingström et al, 1993;Mortazavi and Noin., 2011). Previous studies found evidence for a retention effect of processed starches.…”

Dietary Habits and Caries Prevalence in Older Adults. A Review

“…Alongside the reduction of consumption of sugary foods and drinks, it is also necessary to reduce the consumption of any medicinal products containing sugar that could be prescripted or delivered over the counter to older people and replace them with other, less cariogenic ones [32,34,63]. For example, a very recent clinical study shows that a milk-based nutritional supplement with 8% sucrose used for cases of malnutrition in the elderly increases the risk of coronal and root caries [44].…”