Brick tea consumption is a risk factor for dental caries and dental fluorosis among 12-year-old Tibetan children in Ganzi

Relationships between dental fluorosis and fluoride concentrations in bottled water and groundwater in low-income children in Mexico

Introduction

The aim of the current study was to investigate associations between dental fluorosis in children living in low socioeconomic areas in Mexico, and fluoride concentrations in tap water, fluoride concentrations and in bottled water, and body mass index (BMI).

Methods

A cross-sectional study involving 585 schoolchildren aged 8-12 years was conducted in communities in a southern state of Mexico with >0.7 parts per million (ppm) fluoride in the groundwater. The Thylstrup and Fejerskov index (TFI) was used to evaluate dental fluorosis, and the World Health Organization growth standards were used to calculate age-adjusted and sex-adjusted BMI Z-scores. A BMI Z-score ≤ -1 SD was used as the cut-off point for thinness, and multiple logistic regression models for dental fluorosis (TFI ≥ 4) were constructed.

Results

The mean fluoride concentration in tap water was 1.39 ppm (SD 0.66), and the mean fluoride concentration in bottled water was 0.32 ppm (SD 0.23). Eighty-four children (14.39%) had a BMI Z-score ≤ -1 SD. More than half (56.1%) of the children presented with dental fluorosis in TFI categories ≥ 4. Children living in areas with higher fluoride concentrations in the tap water [odds ratio (OR) 1.57, p = 0.002] and bottled water (OR 3.03, p < .001) were more likely to have dental fluorosis in the severe categories (TFI ≥ 4). BMI Z-score was associated with the probability of dental fluorosis (TFI ≥ 4; OR 2.11, p < 0.001), and the effect size was 29.3%.

Discussion

A low BMI Z-score was associated with a higher prevalence of dental fluorosis in the severe category. Awareness of the fluoride concentrations in bottled water may help prevent dental fluorosis, particularly in children exposed to several high fluoride content sources. Children with a low BMI may be more vulnerable to dental fluorosis.

Brick tea consumption and its relationship with fluorosis in Tibetan areas

Brick tea-type fluorosis (BTF) due to a high intake of brick tea is possible in Tibetan populations, and dental fluorosis (DF) and skeletal fluorosis (SF) are its primary manifestations. To determine the prevalence of DF and SF and their relationships with brick tea intake in Tibetan populations, a literature review was conducted for studies published between 1994 and 2021. The available evidence revealed that brick tea may be produced from older stems and leaves of the tea plant and that the fluoride content of brick tea exceeds the national standard. The harsh environment of the plateau has led to limited food sources for the local Tibetan people who form the habit of drinking tea leaves as a satiation solution to digest greasy food and replenish vitamins, and regular consumption of brick tea leads to excessive exposure of Tibetan residents to fluoride. Studies in Tibet showed that the prevalence of DF in children was 14.06-75.93% in different districts, and the overall pooled prevalence of DF was 26.08%. The prevalence of SF in adults was 19.90-74.77% in different Tibetan districts, and the overall pooled prevalence of SF was 33.84%. The analysis of risk factors showed that the prevalence of BTF may be related to high-altitude and different working and living conditions, and BTF in children may be associated with fluoride intake during mothers' pregnancy and lactation. With the development of bioinformatics research, gene polymorphisms were suspected to be related to susceptibility to fluorosis in Tibetan populations. The study of BTF in Tibetan people needs to be further investigated and standardized, and additional studies evaluating the pathogenesis and preventive measures of BTF are warranted.

Structural and functional dysbiosis of gut microbiota in Tibetan subjects with coronary heart disease

The gut microbiota plays a crucial role in coronary heart disease (CHD). However, only a few studies focusing on the relationship between gut microbiota and CHD in ethnic populations are available. Here, we employed shotgun sequencing of the gut metagenome to analyze the taxonomic composition and functional annotation of the gut microbiota of 14 CHD patients, 13 patients with non-stenosis coronary heart disease (NCHD), and 18 healthy controls (HT) in Tibetan subjects. We found that the α-diversity of the gut microbiota was not significantly different among the three groups., whereas β-diversity was significantly altered in the CHD group compared with HT. Based on the receiver operating characteristic curve (ROC) analysis, the relative abundance of Proteobacteria species effectively distinguished patients with CHD from the control group. Most of the enriched species belonged to Proteobacteria. The pathways that contributed the most to the differences between groups were amino acid metabolism-related pathways, especially lysine biosynthesis. The enzymes of the lysine biosynthesis pathway, including K01714 and K00821, were significantly decreased in the CHD group. Our findings increase the understanding of the association between CHD pathogenesis and gut microbiota in the Tibetan population, thus paving the way for the development of improved diagnostic methods and treatments for Tibetan patients with CHD.

Spatial-Temporal Variation and Health Risk Assessment of Fluoride in Surface Water in the Tibetan Plateau

The Tibetan Plateau (TP) is known as the "Asian Water Tower" and provides vital drinking water for residents of China and Southeast Asian countries. However, large-scale regional research on water quality in this climate-sensitive and ecologically-fragile area is still lacking. Considering that drinking from fluoride-contaminated water poses serious health concerns worldwide, especially in Asian counties, it is urgent to clarify the spatial-temporal distribution characteristics, influencing factors, and health risk of fluoride in surface water in the TP. In this study, a total of 2697 surface water samples from major rivers and typical lakes in the TP were systematically analysed. Overall, fluoride concentrations ranged from 0.003 to 6.240 mg L^-1 and varied among water periods, water basins and even water types. Pearson's correlation analysis showed that the distribution of fluoride concentration was closely related to the regional climate and positively correlated with anthropogenic activities. Probabilistic health risk assessment revealed that potential hazards in the Inner Basin were the highest for all age groups (HR > 1), especially for infants and adults (HR > 3), while the risks in most other water basins were acceptable (HR < 1). Our findings can provide scientific support for fluorosis prevention, and guide water resource utilization in the TP and adjacent regions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-022-00490-4.

A critical review of Fuzhuan brick tea: processing, chemical constituents, health benefits and potential risk

Fuzhuan brick tea (FBT) is a traditional popular beverage in the border regions of China. Nowadays, FBT has been attracted great attention due to its uniquely flavor and various health-promoting functions. An increasing number of efforts have been devoted to the studies on health benefits and chemistry of FBT over the last decades. However, FBT was still received much less attention than green tea, oolong tea and black tea. Therefore, it is necessary to review the current encouraging findings about processing, microorganisms, chemical constituents, health benefits and potential risk of FBT. The fungus fermentation is the key stage for processing of FBT, which is involved in a complex and unique microbial fermentation process. The fungal community in FBT is mainly dominated by "golden flower" fungi, which is identified as Aspergillus cristatus. A great diversity of novel compounds is formed and identified after a series of biochemical reactions during the fermentation process of FBT. FBT shows various biological activities, such as antioxidant, anti-inflammatory, anti-obesity, anti-bacterial, and anti-tumor activities. Furthermore, the potential risk of FBT was also discussed. It is expected that this review could be useful for stimulating further research of FBT.

Potential role of tea extract in oocyte development

Tea is the second most popular beverage in the world and beneficial to health. It has been demonstrated that tea polyphenols can reduce the risk of diseases, such as cancers, diabetes, obesity, Alzheimer's disease, etc. But the knowledge of tea extract on the female germline is limited. Folliculogenesis is a complicated process and prone to be affected by ROS. Tea polyphenols can reduce the accumulation of ROS in folliculogenesis and affect oocyte maturation. Tea extract also influences granulosa cell proliferation and expansion during oocyte growth and maturation. However, the studies about the benefits of tea extract on female germline are few, and the underlying mechanisms are obscure. In the present study, we will mainly discuss the effects of tea extract on ovarian function, oocyte maturation, and the underlying possible mechanisms, and according to the discussion, we suggest that tea extract may have benefits for oocytes at an appropriate dose.

Analysis of dental caries and the impact factors of caries in children aged 3-5 years old in Changdu, Xizang

OBJECTIVES

To investigate caries status and its impact factors in preschool children in plateau and to provide reference for caries prevention in highlands.

METHODS

Examination of caries was performed on 1 597 children aged 3-5 years old in 11 kindergartens in Changdu, Xizang, in accordance with the 4th National Oral Health Survey standards and methods. Their parents were surveyed with the questionnaire regarding oral hygiene habit and consciousness about oral health and related factors. All the data were collected and analyzed.

RESULTS

The prevalence of caries among children aged 3-5 years old in Changdu was 52.85%, with dmft index of 2.44. The caries rate and dmft of children aged 3 years old were lower than those of children aged 4 and 5 years old (P<0.05). No significant difference was observed in the caries rate between males and females (P>0.05). Single-factor analysis showed that the frequency of brushing teeth more than twice a day, low frequency of eating sweets, high frequency of drinking butter tea, and regular oral examination can reduce the rate of caries (P<0.05). Multivariate logistic analysis showed that the frequency of eating sweets, drinking butter tea, and oral examination are related impact factors of caries.

CONCLUSIONS

The prevalence of ca-ries in children aged 3-5 years old in Changdu increases with aging. Good oral hygiene and eating habits and regular oral examination can reduce the rate of caries.

The correlation of altitude with gingival status among adolescents in western China: a cross-sectional study

Periodontal disease is common in Chinese adolescents. There is little information about the effect of different altitudes on gingival health. This study aimed to investigate the gingival status at different altitudes and to identify relative factors that affect adolescents' gingival status. A total of 1033 adolescents aged 12-14 years were included in this cross-sectional study in Ganzi (plateau, 1400 m, 2560 m, 3300 m) and Suining (plain, 300 m). Gingival status was assessed by the presence of gingival bleeding on probing (BOP) and dental calculus (DC). Demographic variables, socioeconomic status, dairy habits and oral health-related knowledge, attitudes and behaviors were obtained via questionnaire. Univariate and multivariate binary logistic regression analyses were performed to identify potential relative factors. A total of 64.09% and 77.15% of adolescents had BOP and DC, respectively. The prevalence rates of BOP and DC were higher in the plateau than the plain (P < 0.05). After adjusting for all other factors and interaction terms, residence altitudes of 2560 m [300 m as reference: P < 0.001, odds ratio (OR) = 4.072] and 3300 m (300 m as reference: P = 0.002, OR = 4.053) were significant relative factors of BOP, and an altitude of 2560 m (300 m as reference: P = 0.001, OR = 3.866, 1400 m as reference: P = 0.001, OR = 3.944) was an important relative factor of DC. Gingival bleeding and calculus deposits were common at different altitudes. High altitude was a significant relative factor of gingival bleeding and calculus deposits.

Predictors of Plasma Fluoride Concentrations in Children and Adolescents

Despite increasing concerns about neurotoxicity of fluoride in children, sources of fluoride exposure apart from municipal water fluoridation are poorly understood. We aimed to describe the associations of demographics, drinking water characteristics, diet, and oral health behaviors with plasma fluoride concentrations in U.S. children. We used data from 3928 6–19-year-olds from the 2013–2016 National Health and Nutrition Examination Survey. We used a 24-h dietary recall to estimate recent consumption of fluoridated tap water and select foods. We estimated the associations of fluoridated tap water, time of last dental visit, use of toothpaste, and frequency of daily tooth brushing with plasma fluoride concentrations. The participants who consumed fluoridated (≥0.7 mg/L) tap water (n = 560, 16%) versus those who did not had 36% (95% CI: 22, 51) higher plasma fluoride. Children who drank black or green tea (n = 503, 13%) had 42% higher plasma fluoride concentrations (95% CI: 27, 58) than non-tea drinkers. The intake of other foods and oral health behaviors were not associated with plasma fluoride concentrations. The consumption of fluoridated tap water and tea substantially increases plasma fluoride concentrations in children. Quantifying the contribution of diet and other sources of fluoride is critical to establishing safe target levels for municipal water fluoridation.

Interannual variation and exposure risk assessment of lead in brick tea in Hubei, China

Lead (Pb) exposure may cause severe health outcomes such as decreased fertility, joint pain and neurological disorders. It is important to know the Pb exposure level in tea and the risk assessment for local residents who drink brick tea daily. This study detected sixteen brick tea samples over 26 years and fifteen green tea samples in 2011 in a southeast city of Hubei province. The Pb content in brick tea was found to increase rapidly with the fast development of industrial activities represented by car sales from 1985 to 2011, which was less susceptible to gasoline. The concentrations of Pb in 16 brick tea were in the range of 1.77-17.8 mg/kg with a mean value of 11.1 mg/kg. Their percentiles P₅₀, P₉₀, and P₉₅ were 13.22, 16.95, and 17.21 mg/kg. A regressional model was built, suggesting strong correlation between the Pb content in brick tea and the car sales. The concentrations of Pb in 15 green tea samples were between 0.36-1.30 mg/kg with a mean value of 0.66 mg/kg and the percentiles P₅₀, P₉₀, and P₉₅ were 0.62, 1.05, and 1.23 mg/kg. The MOE values of brick tea and green tea were all greater than 1 just considering tea consumption which displayed low Pb exposure risk. By adding the Pb exposure by food, the MOE values for green tea were still greater than 1 while the MOE values of brick tea were less than 1 suggesting a potential risk of Pb exposure to the people drinking brick tea daily, who should pay more attention.

Recent Bio-Advances in Metal-Organic Frameworks

Metal-organic frameworks (MOFs) have found uses in adsorption, catalysis, gas storage and other industrial applications. Metal Biomolecule Frameworks (bioMOFs) represent an overlap between inorganic, material and medicinal sciences, utilising the porous frameworks for biologically relevant purposes. This review details advances in bioMOFs, looking at the synthesis, properties and applications of both bioinspired materials and MOFs used for bioapplications, such as drug delivery, imaging and catalysis, with a focus on examples from the last five years.

Aesthetic treatment of dental fluorosis in a 9-year-old girl: Case report

Background/Aim: Dental fluorosis is a specific disturbance of tooth formation caused by excessive intake of fluoride. The discoloration of teeth is the most common reason for parents to seek treatment. The purpose of this paper is to describe the therapeutic management performed in a 9-year-old girl with fluorosis. Case report: A clinical case of a 9-year-old girl diagnosed with fluorosis is reported. The treatment of this clinical case was achieved using microabrasion, which is a minimally invasive method. This technique improves the aesthetics of the teeth without causing significant loss of dental tissue; a characteristic making microabrasion applicable to children as well. Its implementation involved the combined use of 18% hydrochloric acid and pumice on the enamel surface of upper incisors. The improved appearance of the teeth was aesthetically pleasing and, consequently, the patient gained in self-confidence. Conclusions: In the literature, several treatment choices are proposed, depending on the severity of the fluorosis. In our case, microabrasion was applied and the aesthetic outcome satisfied both the patient and the dentist.