Correlation of lithium bioaccessibility from tea (Camellia sinensis L.) with tea type and consumption habits

Lithium Content and Its Nutritional Beneficence, Dietary Intake, and Impact on Human Health in Edibles from the Romanian Market

Lithium (Li) is present in human nutrition based on food intake, and several studies recommend it for treating mood disorders, even if the biological proprieties and biochemical mechanisms represent the basis for its use as an essential element. The Li content was evaluated using the inductively coupled plasma mass spectrometry technique (ICP-MS) in 1071 food and beverage samples from the Romanian market. The results show that Li had a decreasing mean concentration in the food samples as follows: vegetables leafy > bulbous > fructose > leguminous > egg whites > root vegetables > milk products > egg yolks > meats. Approximately a quarter of all data from each dataset category was extreme values (range between the third quartile and maximum value), with only 10% below the detection limit. Mean Li concentration indicated higher values in red wine, white wines, beers, and fruit juice and lower in ciders and bottled waters. A particular interest was addressed to plants for teas and coffee seeds, which showed narrow amounts of Li. For both food and beverages, two similar matrices, including egg whites and yolks and white and red wines, were found to have significant differences, which explains the high variability of Li uptake in various matrices. For 99.65% of the analyzed samples, the estimated daily intake of Li was below the provisional subchronic and chronic reference dose (2 µg/kgbw/day) for adverse effects in several organs and systems. Even so, a risk occurs in consuming bulbous vegetables (Li > 13.47 mg/kg) and fructose solano vegetables (Li > 11.33 mg/kg). The present study's findings indicate that ingesting most of the analyzed beverages and food samples could be considered safe, even if future studies regarding Li content, nutritional aspects, and human cohort diseases must be conducted.

A comprehensive analysis on source-distribution-bioaccumulation-exposure risk of metal(loid)s in various vegetables in peri-urban areas of Shenzhen, China

The health risk induced by metal(loid)s in crops are becoming increasingly serious. In this study, eight major vegetables and rhizosphere soils were collected in a peri-urban area with intense electronic information manufacturing activities. The source, distribution and bioaccumulation of six typical metal(loid)s in different vegetable species were analyzed, and exposure risk through vegetable ingestion was estimated. Results showed that vegetables and agricultural soils in the study area suffered from serious metal(loid)s pollution, especially for Cd and Pb. The bioaccumulation capacity differed greatly among individual metal(loid)s and vegetable categories. In general, the highest transfer factors (TF) for Cd, Pb, and As were found in leafy vegetables, while leguminous vegetables had the highest TF of Cu and Zn and root vegetables had the highest TF for Cr. Significant correlations were found between concentrations in vegetables and rhizosphere soils for most metal(loid)s, the exceptions being Pb and Zn. The enrichment of Pb, Cd, Cr and As was mainly attributed to electronic information manufacturing activities, while the enrichment of Zn, Cu and Cd was associated with the application of commercial fertilizers and pesticides. The health risk associated with vegetable intake decreased in the order of leafy > fruit > leguminous > root vegetables. Leafy vegetables were identified as the category with the highest risk, with the mean risk value of 1.26. Cd was the major risk element for leafy vegetables. The non-carcinogenic risks estimated for leguminous and root vegetables were under the acceptable level. In conclusion, special attention should be paid to the health risks of toxic metal(loid)s in leafy vegetables in peri-urban areas with intense electronic information manufacturing activities. In order to minimize health risk, it is necessary to identify low-risk crops based on a comprehensive consideration of the metal(loid)s' pollution characteristics, transfer factors and local people's consumption behaviors.

Relative contribution of rice and fish consumption to bioaccessibility-corrected health risks for urban residents in eastern China

There are global concerns about dietary exposure to metal(loid)s in foods. However, little is known about the relative contribution of rice versus fish to multiple metal(loid) exposure for the general population, especially in Asia where rice and fish are major food sources. We compared relative contributions of rice and fish consumption to multi-metal(loid) exposure on the city-scale (Nanjing) and province-scale in China. The effects of ingestion rate, metal(loid) level, and bioaccessibility were examined to calculate modeled risk from Cu, Zn, total As (TAs), inorganic As (iAs), Se, Cd, Pb, and methylmercury (MeHg). Metal(loid) levels in rice and fish samples collected from Nanjing City were generally low, except iAs. Metal(loid) bioaccessibilities in fish were higher than those in rice, except Se. Calculated carcinogenic risks induced by iAs intake (indicated by increased lifetime cancer risk, ILCR) were above the acceptable level (1 0 ^-4) in Nanjing City (median: 3 × 10^-4 for female and 4 × 10^-4 for male) and nine provinces (1.4 × 10^-4 to 5.9 × 10^-4) in China. Rice consumption accounted for 85.0% to 99.8% of carcinogenic risk. The non-carcinogenic hazard quotients (HQ) for single metals and hazard index (HI) for multi-metal exposure were < 1 in all cases, indicating of their slight non-carcinogen health effects associated. In Guangdong and Jiangsu provinces, results showed that rice and fish intake contributed similarly to the HI (i.e., 42.6% vs 57.4% in Guangdong and 54.6% vs 45.4% in Jiangsu). Sensitivity analysis indicated that carcinogenic risk was most sensitive to rice ingestion rate and rice iAs levels, while non-carcinogenic hazard (i.e., HQ and HI) was most sensitive to ingestion rate of fish and rice, and Cu concentration in rice. Our results suggest that rice is more important than fish for human dietary metal(loid) exposure risk in China, and carcinogenic risk from iAs exposure in rice requires particular attention.

In vitro assessment of major and trace element bioaccessibility in tea samples

Bioaccessibility of trace elements (Li, Be, Ti, Ga, Cu, Ag, Hg, Cd, Cs, Pt, Tl, Pb, As, Cr, Co, Ni, V, Se, Sn and Sb) and major elements (Rb, Ba, Al, Fe, Zn, Si, Ca, Mg, Mn, Mo, Sr, P and K) in tea infusions has been assessed using an in vitro dialyzability protocol. Gastric simulation (using pepsin solution) and intestinal simulation (using pancreatin and bile salts) were used to perform the in vitro digestion. ICP-MS, ICP-OES and FAES were used for elements determination in digested tea leaves, their infusions and the dialyzate fractions from tea infusions. Microwaves assisted acid digestion was used for the total element determination in tea leaves, while tea infusions were prepared by brewing tea leaves for 5 min in boiling water. The LODs for elements determined in tea leaves were in the range of 0.11-656 ng g^-1 and 0.02-145.6 μg g^-1 for trace and major elements, respectively. For elements' determination in tea infusions, the LODs were ranged between 0.23 and 399.9 ng L^-1 for trace elements and 0.2-1248 μg L^-1 for major elements. The LODs for the elements in the dialyzable fraction varied from 0.018 to 142 μg L^-1. The accuracy of the total element determination was evaluated using certified reference materials (Tea Leaves INCT-TL-1 and Rye Grass). The analytical recoveries were also assessed for analyzed elements in digested tea leaves (95-114%) and their infusions (92-115%), showing good recoveries. Among the studied elements, K was the most abundant element in tea leaves and tea infusions in almost all samples, followed by Ca, Mg, and P. Zn, Cs, and K showed the highest dialyzability percentages up to 84%, 76%, and 54%, respectively, followed by Si and Ca and K that show moderate to high dialyzability percentages. The accuracy of the dialysis process was evaluated using a mass-balance study.

Lithium Content of 160 Beverages and Its Impact on Lithium Status in Drosophila melanogaster

Lithium (Li) is an important micronutrient in human nutrition, although its exact molecular function as a potential essential trace element has not yet been fully elucidated. It has been previously shown that several mineral waters are rich and highly bioavailable sources of Li for human consumption. Nevertheless, little is known about the extent in which other beverages contribute to the dietary Li supply. To this end, the Li content of 160 different beverages comprising wine and beer, soft and energy drinks and tea and coffee infusions was analysed by inductively coupled plasma mass spectrometry (ICP-MS). Furthermore, a feeding study in Drosophila melanogaster was conducted to test whether Li derived from selected beverages changes Li status in flies. In comparison to the average Li concentration in mineral waters (108 µg/L; reference value), the Li concentration in wine (11.6 ± 1.97 µg/L) and beer (8.5 ± 0.77 µg/L), soft and energy drinks (10.2 ± 2.95 µg/L), tea (2.8 ± 0.65 µg/L) and coffee (0.1 ± 0.02 µg/L) infusions was considerably lower. Only Li-rich mineral water (~1600 µg/L) significantly increased Li concentrations in male and female flies. Unlike mineral water, most wine and beer, soft and energy drink and tea and coffee samples were rather Li-poor food items and thus may only contribute to a moderate extent to the dietary Li supply. A novelty of this study is that it relates analytical Li concentrations in beverages to Li whole body retention in Drosophila melanogaster.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80-5.0%), accuracy (< 5%), recoveries of elements (97.4-105%), and their detection limits (0.075-1.1 μg L-1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)-40.7% (Ca) and 4.65% (Al)-46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Relationship between suicide mortality and lithium in drinking water: A systematic review and meta-analysis

BACKGROUND

Lithium at therapeutic doses has protective effects against suicide in clinical practice. This meta-analysis aimed to investigate the relationship between lithium concentration in drinking water and suicide mortality in the general population.

METHODS

A systematic search was conducted in Web of Knowledge, PubMed, ScienceDirect, and Scopus to find papers reporting the crude relationship between drinking water lithium and suicide incidence in the general population until June 2019. The pooled effect measure was expressed as odds ratio (OR) and 95% confidence interval (CI) using the random-effects model.

RESULTS

We retrieved 308 English original articles, of which 13 ecologic studies with a total sample size of 939 regions and one cohort study with a sample size of 3,740,113 people were eligible for the meta-analysis. A significant relationship was found between the lithium concentration in drinking water and reduced suicide mortality (OR= 0.42; 95% CI: 0.27-0.67; p-value <0.01). Ten studies reported gender-specific responses to lithium, with the pooled estimates as follows: OR= 0.54; 95% CI: 0.35-0.84; p-value <0.01 for men, OR= 0.70; 95% CI: 0.48-1.01; p-value =0.057 for women, and OR= 0.63; 95% CI: 0.47-0.83; p-value <0.01 for total.

LIMITATIONS

The study was limited to the assessment of the crude relationship between lithium exposure and suicide rate without considering the role of confounders.

CONCLUSIONS

Lithium in drinking water is dose-dependently associated with reduced suicide mortality at least in ecological studies. However, we need well-designed clinical trials to confirm the protective effect of drinking water lithium intake against suicide.