Micronutrients and bioactive compounds in oral inflammatory diseases

Assessing the association between tea intake and risk of dental caries and periodontitis: a two-sample Mendelian randomization study

Tea is an indispensable beverage in people's daily life. However, the relationship between tea intake and dental caries and periodontitis is controversial. We extracted datasets for tea intake and oral diseases from genome-wide association studies (GWASs) conducted by the UK Biobank and the Gene Lifestyle Interactions in Dental Endpoints consortium. We selected 38 single-nucleotide polymorphisms (SNPs) significantly associated with tea intake as instrumental variables (IVs) (P < 5.0 × 10-8). Mendelian randomization (MR) was performed to investigate the potential causality between tea intake and caries and periodontitis. Multivariable Mendelian randomization (MVMR) analyses were utilized to estimate causal effects of tea intake on risk of caries and periodontitis after adjusting for smoking, body mass index (BMI), and socioeconomic factors. The results showed that higher tea intake was suggestively associated with fewer natural teeth (β = - 0.203; 95% CI = 0.680 to 0.980; P = 0.029) and higher risk of periodontitis (OR = 1.622; 95% CI = 1.194 to 2.205; P = 0.002). After Bonferroni correction, the causality of tea intake on periodontitis remained significant. The significance of periodontitis disappeared after adjusting for the socioeconomic factors in MVMR (OR = 1.603; 95% CI = 0.964 to 2.666; P = 0.069). Tea intake had no association with risk of caries. Statistical insignificance of the heterogeneity test and pleiotropy test supported the validity of the MR study. Our results provide insight into the potential relationship between tea intake and oral diseases from a dietary lifestyle perspective, which may help prevent oral diseases.

A pro-inflammatory diet is associated with an increased odds of periodontitis: finding from a case-control study

OBJECTIVE

This study aimed to evaluate the inflammatory effect of diet using the dietary Inflammatory Index (DII) on the odds of periodontitis. We hypothesized that a diet with high DII scores (a pro-inflammatory diet) is associated with high chronic and systematic inflammation resulting in periodontitis. Periodontitis is one of the most common inflammatory diseases that affect the tissues around the tooth and results from the interaction of bacterial infection and the host immune response. The DII shows the association between different food components and the level of specific inflammatory biomarkers.

METHOD

The food intake of 87 cases with diagnosed periodontitis and 87 control was assessed using a 163-item valid food frequency questionnaire (FFQ). The DII was calculated based on the FFQ data. Logistic and linear regression models adjusting for multivariable confounders were used to investigate the odds ratio (OR) and 95% confidence intervals (CI) of developing periodontitis.

RESULTS

There was a significant difference between the mean intake of micronutrients and food groups, including saturated fatty acids (SFAs), iron, magnesium, manganese, vitamin C, crude fiber, selenium, chromium, whole fiber, caffeine, dairy, and meat, between patients with periodontitis and the control group (p-value˂0.05). DII scores in this study ranged from -3.13 to + 0.99. However, the periodontitis OR in the raw and multivariable-adjusted models was not statistically significant (multivariable-adjusted OR tertiles 1 vs. tertiles 3 = 2.00, 95%CI: 0.4-90.42, p-value = 0.08). A similar result was also observed in the continuous model of DII (multivariable-adjusted OR DII continuous = 1.93, 95%CI: 0.30-98.79, p-value = 0.05).

CONCLUSION

Although the OR was not statistically significant in crude models, a significant trend was found in multivariable-adjusted models. The results were promising since this is the first study to examine the association between diet-induced inflammation and dental disease. It is advisable to conduct additional studies with high sample sizes and other designs, such as prospective studies.

The Impact of Chronic Kidney Disease on Nutritional Status and Its Possible Relation with Oral Diseases

Several studies have demonstrated a strong relation between periodontal diseases and chronic kidney disease (CKD). The main mechanisms at the base of this link are malnutrition, vitamin dysregulation, especially of B-group vitamins and of C and D vitamins, oxidative stress, metabolic acidosis and low-grade inflammation. In particular, in hemodialysis (HD) adult patients, an impairment of nutritional status has been observed, induced not only by the HD procedures themselves, but also due to numerous CKD-related comorbidities. The alteration of nutritional assessment induces systemic manifestations that have repercussions on oral health, like oral microbiota dysbiosis, slow healing of wounds related to hypovitaminosis C, and an alteration of the supporting bone structures of the oral cavity related to metabolic acidosis and vitamin D deficiency. Low-grade inflammation has been observed to characterize periodontal diseases locally and, in a systemic manner, CKD contributes to the amplification of the pathological process, bidirectionally. Therefore, CKD and oral disease patients should be managed by a multidisciplinary professional team that can evaluate the possible co-presence of these two pathological conditions, that negatively influence each other, and set up therapeutic strategies to treat them. Once these patients have been identified, they should be included in a follow-up program, characterized by periodic checks in order to manage these pathological conditions.

Bitter and sweet taste perception: relationships to self-reported oral hygiene habits and oral health status in a survey of Australian adults

Background

Oral health, an essential part of general health and well-being, is influenced by multiple factors, including oral hygiene habits and dietary factors. Dietary preferences are influenced by variation in taste perceptions and threshold tasting. Polymorphisms in specific genes for sweet and bitter taste receptors and bitter taste perception have been associated with dental caries. However, taste is complex with multiple receptors, each with multiple potential polymorphisms contributing to taste perception as well as social, cultural, and environmental influences. Additionally, these association studies have been conducted in restricted cohorts (e.g., children only). Furthermore, outcomes have been limited to dental caries and studies between taste perception and oral hygiene habits have not been completed.

Methods

A cross-sectional online survey was conducted to investigate the relationships between bitter and sweet taste perception (liking and intensity of index food items), self-reported oral hygiene habits and oral health (n = 518).

Results

Higher mean intensity scores for bitter (16–21%) and sweet (< 5%-60%) were seen with higher frequencies of oral hygiene habits (brushing, use of mouthwash, chewing gum and tongue cleaning). Lower mean bitter liking scores (18–21%) were seen with higher frequencies of oral hygiene habits (brushing, mouthwash use, floss use and chewing gum). Sweet liking scores varied by reported frequency of mouthwash use and flossing only, with mixed patterns of variance. Mean bitter and sweet intensity perception scores varied with the number of dental caries ((13–20% higher in those with 3 or more caries, compared to none).

Conclusions

While there were numerous relationships identified between liking and perception of sweet and bitter and oral health outcomes, the magnitude and direction of associations varied by outcome. The direction of the associations cannot be inferred due to the cross-sectional nature of the study. The demonstrated relationships justify further future investigations, which could help better understand if taste liking and perception is impacted by oral hygiene and health, or vice versa. This could be important in understanding the causation and progression of oral health diseases or the development of novel therapeutics for oral health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01910-8.