Sugar-sweetened beverages and periodontal disease: A systematic review

This systematic review aims to determine the association between the consumption of sugar-sweetened beverages (SSBs) and periodontal disease. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to conduct a literature search on five electronic databases till January 2022. Systemically healthy individuals consuming SSBs and presenting periodontal disease (gingivitis/periodontitis) were included. The modified Newcastle-Ottawa Scale and the Grading of Recommendation Assessment Development and Evaluation criteria were respectively used to assess the risk of bias and the evidence's quality. Of the 1303 eligible records identified in the initial search, ten studies (nine cross-sectional and one case-control) were selected for the final review. Among the included articles, five reported SSBs intake in the form of carbonated soft drinks, two as sugary drinks, two as soft drinks, and one as coffee with added sugar. Four studies reported gingivitis as an outcome, while the remaining six studies reported periodontitis using validated indices. The included studies were of medium to high quality. Consumption of SSBs may increase gingival bleeding, thereby gingivitis and the risk of periodontitis. Intake of added sugars like SSBs should be considered as a potential factor during gingival/periodontal risk assessment. Further studies are warranted to establish additional evidence of association.

Food-Derived Uremic Toxins in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have a higher cardiovascular risk compared to the average population, and this is partially due to the plasma accumulation of solutes known as uremic toxins. The binding of some solutes to plasma proteins complicates their removal via conventional therapies, e.g., hemodialysis. Protein-bound uremic toxins originate either from endogenous production, diet, microbial metabolism, or the environment. Although the impact of diet on uremic toxicity in CKD is difficult to quantify, nutrient intake plays an important role. Indeed, most uremic toxins are gut-derived compounds. They include Maillard reaction products, hippurates, indoles, phenols, and polyamines, among others. In this review, we summarize the findings concerning foods and dietary components as sources of uremic toxins or their precursors. We then discuss their endogenous metabolism via human enzyme reactions or gut microbial fermentation. Lastly, we present potential dietary strategies found to be efficacious or promising in lowering uremic toxins plasma levels. Aligned with current nutritional guidelines for CKD, a low-protein diet with increased fiber consumption and limited processed foods seems to be an effective treatment against uremic toxins accumulation.

Methylglyoxal Causes Cell Death in Neural Progenitor Cells and Impairs Adult Hippocampal Neurogenesis

Methylglyoxal (MG) is formed during normal metabolism by processes like glycolysis, lipid peroxidation, and threonine catabolism, and its accumulation is associated with various degenerative diseases, such as diabetes and arterial atherogenesis. Furthermore, MG has also been reported to have toxic effects on hippocampal neurons. However, these effects have not been studied in the context of neurogenesis. Here, we report that MG adversely affects hippocampal neurogenesis and induces neural progenitor cell (NPC) death. MG significantly reduced C17.2 NPC proliferation, and high concentration of MG (500 μM) induced cell death and elevated oxidative stress. Further, MG was found to activate the ERK signaling pathway, indicating elevated stress response. To determine the effects of MG in vivo, mice were administrated with vehicle or MG (0.5 or 1 % in drinking water) for 4 weeks. The numbers of BrdU-positive cells in hippocampi were significantly lower in MG-treated mice, indicating impaired neurogenesis, but MG did not induce neuronal damage or glial activations. Interestingly, MG reduced memory retention when administered to mice at 1 % but not at 0.5 %. In addition, the levels of hippocampal BDNF and synaptophysin were significantly lower in the hippocampi of mice treated with MG at 1 %. Collectively, our findings suggest MG could be harmful to NPCs and to hippocampal neurogenesis.

A population-based study on the association between the intake of soft drinks and periodontal disease in Taiwanese adults aged 35-44 years (KCIS no. 33)

OBJECTIVE

To elucidate the association between the intake of soft drinks and periodontal disease (PD) among Taiwanese middle-aged adults.

DESIGN

The cross-sectional design was employed to assess a dose-response relationship between the intake of soft drinks and PD after controlling for relevant confounding factors, with adjusted odds ratios obtained from a multivariate logistic regression model.

SETTING

Keelung Community-based Integrated Screening (KCIS) programme, Keelung, Taiwan.

SUBJECTS

Participants (n 10 213) aged 35-44 years who had undergone oral checks for PD between 2005 and 2009.

RESULTS

A dose-response relationship between the intake of soft drinks and elevated risk for PD defined by community periodontal index ≥3 (the current status of PD) was noted (P=0·02 by trend test). Compared with infrequent intake of soft drinks (≤2 times/week), the adjusted OR increased from 1·05 (95 % CI 0·92, 1·20) for the frequency of 3-4 times/week to 1·17 (95 % CI 1·03, 1·34) for the frequency of ≥5 times/week. A similar trend (P<0·01) was also observed for PD defined by loss of attachment ≥1 (representing the long-term cumulative gum damage due to PD).

CONCLUSIONS

A dose-response relationship between the intake frequency of soft drinks and PD was observed in Taiwanese middle-aged adults. Such evidence could be used in health promotion to support reductions in soft drink intake.

Metabolic transit of dietary methylglyoxal

Methylglyoxal (MGO) is responsible for the pronounced antibacterial activity of manuka honey, in which it may reach concentrations up to 800 mg/kg. As MGO formed in vivo is discussed to play a role in diabetic complications, the metabolic transit of dietary MGO was studied within a 3 day dietary recall with four healthy volunteers. Determination of MGO in 24 h urine was performed with GC-MS after derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine, and D-lactate was quantified enzymatically. Following a diet virtually free from MGO and other glycation compounds, a defined amount of MGO (500 μmol in manuka honey) was administered in the morning of day 2. Renal excretion was between 0.1 and 0.4 μmol/day for MGO and between 50 and 220 μmol/day for D-lactate. No influence on excretion of both compounds was observed following administration of MGO. To investigate the stability of MGO under physiological conditions, a simulated in vitro gastrointestinal digestion was performed with MGO-containing honey. After 8 h of in vitro digestion, only 5-20% of the initial methylglyoxal was recovered. This indicates that dietary MGO is rapidly degraded during the digestion process in the intestine and, therefore, exerts no influence on the MGO level in vivo.

Resveratrol protects mouse oocytes from methylglyoxal-induced oxidative damage

Methylglyoxal, a reactive dicarbonyl compound, is mainly formed from glycolysis. Methylglyoxal can lead to the dysfunction of mitochondria, the depletion of cellular anti-oxidation enzymes and the formation of advanced glycation ends. Previous studies showed that the accumulation of methylglyoxal and advanced glycation ends can impair the oocyte maturation and reduce the oocyte quality in aged and diabetic females. In this study, we showed that resveratrol, a kind of phytoalexin found in the skin of grapes, red wine and other botanical extracts, can alleviate the adverse effects caused by methylglyoxal, such as inhibition of oocyte maturation and disruption of spindle assembly. Besides, methylglyoxal-treated oocytes displayed more DNA double strands breaks and this can also be decreased by treatment of resveratrol. Further investigation of these processes revealed that methylglyoxal may affect the oocyte quality by resulting in excessive reactive oxygen species production, aberrant mitochondrial distribution and high level lipid peroxidation, and resveratrol can block these cytotoxic changes. Collectively, our results showed that resveratrol can protect the oocytes from methylglyoxal-induced cytotoxicity and this was mainly through the correction of the abnormity of cellular reactive oxygen species metabolism.

Soft drink intake in relation to incident ischemic heart disease, stroke, and stroke subtypes in Japanese men and women: the Japan Public Health Centre-based study cohort I

BACKGROUND

Soft drink intake has been associated with obesity and diabetes, but its relation with risk of cardiovascular disease (CVD) is limited.

OBJECTIVE

We examined the association between soft drink intake and risk of CVD in a Japanese population.

DESIGN

This was a prospective study in 39,786 Japanese men and women aged 40-59 y in which soft drink intake was determined by using a self-administered food-frequency questionnaire. Follow-up was from 1990 to 2008. HRs and 95% CIs of incidence were calculated according to categories of soft drink intake.

RESULTS

During 18 y of follow-up, we ascertained 453 incident cases of ischemic heart disease (IHD) and 1922 cases of stroke, including 859 hemorrhagic and 1047 ischemic strokes. Soft drink intake was positively associated with risk of total stroke and more specifically ischemic stroke for women; the multivariable HR (95% CI) in the highest soft drink intake (almost every day) category compared with the lowest intake (never or rarely) category was 1.21 (0.88, 1.68; P-trend = 0.02) for total stroke and 1.83 (1.22, 2.75; P-trend = 0.001) for ischemic stroke. That association did not change significantly after the exclusion of early incident cases within 3-9 y from baseline. A nonsignificant inverse trend for risks of total and ischemic strokes was shown for men, and it was weakened after the exclusion of early incident cases or after the exclusion of participants with baseline comorbidities. Soft drink intake was not associated with risk of IHD or hemorrhagic stroke for either sex.

CONCLUSION

Soft drink intake is associated with higher risk of ischemic stroke for women.