Abstract
Highlights
- • We evaluated longitudinal associations between repeated fluoride measures and cardiometabolic outcomes in children.
- • Dietary fluoride altered levels of lipids, adipokines, and diabetes-related biomarkers in children during 4–8 years of age.
- • Dietary fluoride increased zBMI and odds of overweight/obesity status in children at age 8.
- • Fewer, though consistent, associations were observed with respect to urinary fluoride.
- • Stronger fluoride-induced associations were observed in boys at age 8 and in girls prior to age 8.
Background/Aim
Fluoride is a natural mineral present in food, water, and dental products, constituting ubiquitous long-term exposure in early childhood and across the lifespan. Experimental evidence shows fluoride-induced lipid disturbances with potential implications for cardiometabolic health. However, epidemiological studies are scarce. For the first time, we evaluated associations between repeated fluoride measures and cardiometabolic outcomes in children.
Methods
We studied ? 500 Mexican children from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort with measurements on urinary fluoride at age 4, and dietary fluoride at ages 4, 6, and 8 years approximately. We used covariate-adjusted linear mixed-effects and linear regression models to assess fluoride associations with multiple cardiometabolic outcomes (ages 4–8): lipids (total cholesterol, HDL, LDL, and triglycerides), glucose, HbA1c, adipokines (leptin and adiponectin), body fat, and age- and sex-specific z-scores of body mass index (zBMI), waist circumference, and blood pressure.
Results
Dietary fluoride intake at age 4 was associated with annual increases in triglycerides [? per-fluoride-doubling = 2.02 (95 % CI: 0.37, 3.69)], cholesterol [? = 1.46 (95 % CI: 0.52, 2.39)], HDL [? = 0.39 (95 % CI: 0.02, 0.76)], LDL [? = 0.87 (95 % CI: 0.02, 1.71)], and HbA1c [? = 0.76 (95 % CI: 0.28, 1.24)], and decreased leptin [? = -3.58 (95 % CI: ?6.34, ?0.75)] between the ages 4 and 8. In cross-sectional analyses at age 8, higher tertiles of fluoride exposure were associated with increases in zBMI, triglycerides, glucose, and leptin (p-tertile trend < 0.05). Stronger associations were observed in boys at year 8 and in girls prior to year 8 (p-sex interaction < 0.05). Fewer but consistent associations were observed for urinary fluoride at age 4, indicating increased annual changes in HDL and HbA1c with higher fluoride levels.
Conclusion
Dietary fluoride exposures in early- and mid-childhood were associated with adverse cardiometabolic outcomes in school-aged children. Further research is needed to elucidate whether these associations persist at later ages.
Excerpt:
4. Discussion
… Fluoridation of drinking water has been implemented in multiple countries to promote dental health. These findings can help inform whether fluoridation practices are an optimal cost-effective measure to improve health. Even though fluoride can be excreted from the body within hours, a potential long-lasting endocrine-disrupting role of the chemical should be considered in future studies. In this study, we identified an environmental and modifiable potential risk factor for cardiometabolic disease in the sensitive childhood period, which is of public health relevance due to the rising cardiometabolic disease epidemic worldwide and the particular high prevalence (>38 %) and rising trend of overweight and obesity in Mexican children ages 5–11 (INSP, 2020, Shamah-Levy et al., 2018). Furthermore, since 1993, Mexico has had a national program of iodized and fluoridated salt, which mandates that for every kg of salt there be approximately 200 mg to 250 mg of fluoride mixture (Secretaría de Salud, 1994, Gobierno de México, 2023). These results could be of high relevance in a country like Mexico where in the general population the intake of salt, the primary source of fluoride other than dental products, largely exceeds the WHO recommendation (Vargas-Meza et al., 2016), and can be informative for public health interventions.
Original abstract and full-text study online at https://www.sciencedirect.com/science/article/pii/S0160412023006487?via%3Dihub
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