Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada.
JAMA pediatrics. 2019
Plain language summary
Fluoride is added to the water supply in some parts of the UK, US and Canada to help prevent tooth decay. However, some people think that fluoride could be harmful to health, and may affect brain development in foetuses. The aim of this Canadian study was to determine whether a mother’s exposure to fluoride during pregnancy was associated with her child’s IQ. Researchers recruited a total of 369 pregnant women from both fluoridated and non-fluoridated areas and measured the amount of fluoride in their urine. The children’s IQs were measured when they were aged 3 to 4 years. The researchers found that overall, maternal exposure to higher levels of fluoride during pregnancy was associated with lower IQ scores in children aged 3 to 4 years. The relationship was much stronger in boys than it was in girls. These findings indicate a possible need to reduce fluoride intake during pregnancy.
Importance: The potential neurotoxicity associated with exposure to fluoride, which has generated controversy about community water fluoridation, remains unclear. Objective: To examine the association between fluoride exposure during pregnancy and IQ scores in a prospective birth cohort. Design, Setting, and Participants: This prospective, multicenter birth cohort study used information from the Maternal-Infant Research on Environmental Chemicals cohort. Children were born between 2008 and 2012; 41% lived in communities supplied with fluoridated municipal water. The study sample included 601 mother-child pairs recruited from 6 major cities in Canada; children were between ages 3 and 4 years at testing. Data were analyzed between March 2017 and January 2019. Exposures: Maternal urinary fluoride (MUFSG), adjusted for specific gravity and averaged across 3 trimesters available for 512 pregnant women, as well as self-reported maternal daily fluoride intake from water and beverage consumption available for 400 pregnant women. Main Outcomes and Measures: Children's IQ was assessed at ages 3 to 4 years using the Wechsler Primary and Preschool Scale of Intelligence-III. Multiple linear regression analyses were used to examine covariate-adjusted associations between each fluoride exposure measure and IQ score. Results: Of 512 mother-child pairs, the mean (SD) age for enrollment for mothers was 32.3 (5.1) years, 463 (90%) were white, and 264 children (52%) were female. Data on MUFSG concentrations, IQ scores, and complete covariates were available for 512 mother-child pairs; data on maternal fluoride intake and children's IQ were available for 400 of 601 mother-child pairs. Women living in areas with fluoridated tap water (n = 141) compared with nonfluoridated water (n = 228) had significantly higher mean (SD) MUFSG concentrations (0.69 [0.42] mg/L vs 0.40 [0.27] mg/L; P = .001; to convert to millimoles per liter, multiply by 0.05263) and fluoride intake levels (0.93 [0.43] vs 0.30 [0.26] mg of fluoride per day; P = .001). Children had mean (SD) Full Scale IQ scores of 107.16 (13.26), range 52-143, with girls showing significantly higher mean (SD) scores than boys: 109.56 (11.96) vs 104.61 (14.09); P = .001. There was a significant interaction (P = .02) between child sex and MUFSG (6.89; 95% CI, 0.96-12.82) indicating a differential association between boys and girls. A 1-mg/L increase in MUFSG was associated with a 4.49-point lower IQ score (95% CI, -8.38 to -0.60) in boys, but there was no statistically significant association with IQ scores in girls (B = 2.40; 95% CI, -2.53 to 7.33). A 1-mg higher daily intake of fluoride among pregnant women was associated with a 3.66 lower IQ score (95% CI, -7.16 to -0.14) in boys and girls. Conclusions and Relevance: In this study, maternal exposure to higher levels of fluoride during pregnancy was associated with lower IQ scores in children aged 3 to 4 years. These findings indicate the possible need to reduce fluoride intake during pregnancy.
Egg Consumption in U.S. Children is Associated with Greater Daily Nutrient Intakes, including Protein, Lutein + Zeaxanthin, Choline, α-Linolenic Acid, and Docosahexanoic Acid.
Plain language summary
Dietary guidelines recommend children and adolescents consume nutrient-dense foods to promote growth and development, and recently eggs have been included in these recommendations. At present, there are no studies in children and adolescents that have examined nutrient-related associations of egg consumption. Therefore, the aim of this study was to investigate egg consumption and nutrient intakes, diet quality and growth outcomes relative to non-egg consumers. Using cross-sectional data from the US National Health and Nutrition Examination Survey (NHANES), data from 3,299 egg consumers and 17,030 non-egg consumers aged 2-18 was examined. Compared with non-egg consumption, egg consumption was associated with elevated intake of protein, healthy fats, antioxidants and various vitamins and minerals, and lower intake of sugar. There were several shortfall nutrients associated with egg consumption including fibre, iron, and folate. No associations were found when examining diet quality and growth-relate measures. This analysis demonstrated several nutrient-related benefits to support the continued inclusion of eggs in the dietary patterns of children and adolescents. Based on these results, the authors conclude this study illustrates an opportunity to communicate the benefits linked with egg consumption to individuals that influence children and adolescents.
undefined: Dietary pattern recommendations include consuming a variety of nutrient-dense foods in children and adolescents to promote optimal growth and development. The current study investigated associations with egg consumption and nutrient intakes, diet quality, and growth outcomes relative to non-egg consumers. The analysis used data from the U.S. National Health and Nutrition Examination Survey (NHANES) 2001-2012 in children and adolescents aged 2-18 years ( = 3,299, egg consumers; = 17,030, egg non-consumers). Daily energy and nutrient intakes were adjusted for the complex sample design of NHANES using appropriate weights. Consuming eggs was associated with increased daily energy intake relative to non-egg consumption. Children and adolescents consuming eggs had elevated daily intake of protein, polyunsaturated, monounsaturated and total fat, α-linolenic acid, docosahexaenoic acid (DHA), choline, lutein + zeaxanthin, vitamin D, potassium, phosphorus, and selenium. Egg consumers had greater consumption, sodium, saturated fat, with reduced total and added sugar versus egg non-consumers. The analysis also showed that egg consumption was linked with lower intake of dietary folate, iron, and niacin. No associations were determined when examining diet quality and growth-related measures. A sub-analysis considering socioeconomic status showed that egg consumption was positively related with daily lutein + zeaxanthin and DHA intake. The current analysis demonstrated several nutrient-related benefits to support the continued inclusion of eggs in the dietary patterns of children and adolescents.
Role of early hormonal and nutritional experiences in shaping feeding behavior and hypothalamic development.
The Journal of nutrition. 2010;140(3):653-7
Plain language summary
Obesity in children and adults is increasingly becoming a serious health problem, particularly in Western countries. The precise biological mechanisms underlying the disease are not clear, and it is equally unclear why certain individuals are more predisposed than others. Research suggests that the perinatal conditions and periods of organ development may predispose individuals to obesity later in life. For example, maternal malnutrition, diabetes and/or obesity during pregnancy can increase susceptibility to obesity. The hypothalamus, the region of the brain associated with feeding and glucose homeostasis, develops primarily in utero and is thought to be influenced by hormones such as leptin, ghrelin and insulin that may indicate nutrient availability in the environment. Imbalances in these hormones therefore may have an impact on the developing hypothalamus, leading to abnormalities in appetite control and feeding. These hormones may also be involved in neural growth and development directly.
Obesity in adults and children is increasingly becoming a major health problem worldwide. However, the precise biological mechanisms governing this disease have not been fully elucidated. Obesity involves the complex interaction of a wide range of environmental and genetic factors. Additionally, there is now a growing body of evidence suggesting that alterations in metabolic environment during important periods of organ development can predispose individuals to later development of obesity and diabetes. Maternal obesity or malnutrition during pregnancy increases the risk for metabolic disorders (including obesity) in the offspring. Similarly, early postnatal overnutrition also predisposes offspring to adult obesity. The hypothalamus appears to play an essential role in controlling appetite. It undergoes a tremendous growth beginning early in gestation and continuing during the postnatal period. These developmental windows represent periods of sensitivity for hypothalamic development during which alterations in the nutritional and/or hormonal environment may perturb hypothalamic development and subsequent function.