Added Sugar Consumption and Chronic Oral Disease Burden among Adolescents in Brazil.

Chronic oral diseases are rarely studied together, especially with an emphasis on their common risk factors. This study examined the association of added sugar consumption on "chronic oral disease burden" among adolescents, with consideration of obesity and systemic inflammation pathways through structural equation modeling. A cross-sectional study was conducted of a complex random sample of adolescent students enrolled at public schools in São Luís, Brazil ( n = 405). The outcome was chronic oral disease burden, a latent variable based on the presence of probing depth ≥4 mm, bleeding on probing, caries, and clinical consequences of untreated caries. The following hypotheses were tested: 1) caries and periodontal diseases among adolescents are correlated with each other; 2) added sugar consumption and obesity are associated with chronic oral disease burden; and 3) chronic oral disease burden is linked to systemic inflammation. Models were adjusted for socioeconomic status, added sugar consumption, oral hygiene behaviors, obesity, and serum levels of interleukin 6 (IL-6). All estimators of the latent variable chronic oral disease burden involved factor loadings ≥0.5 and P values <0.001, indicating good fit. Added sugar consumption (standardized coefficient [SC] = 0.212, P = 0.005), high IL-6 levels (SC = 0.130, P = 0.036), and low socioeconomic status (SC = -0.279, P = 0.001) were associated with increased chronic oral disease burden values. Obesity was associated with high IL-6 levels (SC = 0.232, P = 0.001). Visible plaque index was correlated with chronic oral disease burden (SC = 0.381, P < 0.001). Our finding that caries and periodontal diseases are associated with each other and with added sugar consumption, obesity, and systemic inflammation reinforces the guidance of the World Health Organization that any approach intended to prevent noncommunicable diseases should be directed toward common risk factors.

Phenotypic diversity of starch granules in cassava germplasm.

Demand for the development of cassava varieties with different native starches has guided the search for these characteristics in the germplasm of Manihot esculenta Crantz. Therefore, the objective of this study was to estimate the genetic diversity of cassava accessions for root and starch granule characteristics to guide the future industrial application of this species. Starches from 56 accessions were evaluated for the number of granules in 1 g of starch (NTG), area (AG, µm2), length (LG, µm), width (WG, µm), starch granule roundness (Round), dry matter content in the roots (DMC, %), pulp color (PulCo), and cyanogenic compounds (HCN). Images captured by light microscopy were used to determine the average phenotypic values, and these were further analyzed by principal component analysis (PCA) considering mixed data (quantitative and qualitative). Significant differences between the cassava accessions for all traits measured revealed wide variability in starch granule characteristics. Four diversity groups with better fitness for the classification of cassava accessions based on PulCo were identified, in comparison with HCN. Accessions with differential starch characteristics were identified, and crossings for the generation of segregating populations in order to obtain table and industry varieties have been proposed.

Polymorphism of starch pathway genes in cassava.

The distribution and frequency of single nucleotide polymorphisms (SNPs) can help to understand changes associated with characteristics of interest. We aimed to evaluate nucleotide diversity in six genes involved in starch biosynthesis in cassava using a panel of 96 unrelated accessions. The genes were sequenced, aligned, and used to obtain values for nucleotide diversity (π), segregating sites (θ), Tajima's D test, and neighbor-joining (NJ) clustering. On average, one SNP per 147 and 171 bp was identified in exon and intron regions, respectively. Thirteen heterozygous loci were found. Three of seven SNPs in the exon region resulted in non-synonymous replacement or four synonymous substitutions. However, no associations were noted between SNPs and root dry-matter content. The parameter π ranged from 0.0001 (granule bound starch synthase I) to 0.0033 (α-amylase), averaging 0.0011, while θ ranged from 0.00014 (starch branching enzyme) to 0.00584 (starch synthase I), averaging 0.002353. The θ diversity value was typically double that of the π. Results of the D test did not suggest any evidence of deviance of neutrality in these genes. Among the evaluated accession, 82/96 were clustered using the NJ method but without a clear separation of the root dry-matter content, root pulp coloration, and classification of the cyanogenic compound content. High variation in genes of the starch biosynthetic pathway can be used to identify associations with the functional properties of starch for the use of polymorphisms for selection purposes.