Dietary fluoride intake for fully formula-fed infants in New Zealand: impact of formula and water fluoride

Research on commercial milk formulas for young children: A scoping review

A scoping review of publications about commercial milk formulas intended for or consumed by children 12-36 months (CMF 12-36) was conducted. This review aimed to comprehensively map the existing literature, identify key concepts in the field and understand its evolution through time. A total of 3329 articles were screened and 220 were included, published between 1986 and 2024. Most works were published after 2016 (70.0%) and in high-income countries (71.8%). Original studies were the vast majority (81.8%) of publications. Most publications dealt with feeding practices or analysed the composition and/or contamination of specific products (44.1% and 35.9%), but since the late 2000s, publications about marketing, policy, legislation, and consumer perception started to appear. Most published works (65.5%) did not focus exclusively on CMF 12-36 and included formulas for other demographics or other foods. About half of the works (55.5%) did not consider CMF 12-36 to be a breast milk substitute. We found 81 distinct product denominations used to refer to CMF 12-36, Growing Up Milk was the most common (25.9%). CMF industry was involved in 41.8% of all analysed works, and industry participation and funding were not always clearly informed (22.5% lacked a conflict of interest statement, and 25.5% did not present any information about funding). In the last decade, publications about CMF 12-36 have increased in volume and diversified in scope and subject matter. CMF-industry participation has always been and still is present in the field, so possible vested interests should be taken into account when appreciating the literature.

Worldwide Variations in Fluoride Content in Beverages for Infants

In situations where breastfeeding is impractical, milk formulas have emerged as the primary choice for infant nutrition. Numerous global studies have scrutinized the fluoride content in these formulas, uncovering fluctuations in fluoride levels directly associated with the method of preparation. This variability poses a potential risk of elevated fluoride concentrations and, consequently, an increased susceptibility to dental fluorosis in infants. The primary objective of this review is to intricately delineate the fluoride content in dairy formulas and emphasize the variability of these values concerning their reconstitution process. The review's findings reveal that, among the 17 studies assessing fluoride levels in infant formula, milk-based formulas exhibit a range of 0.01-0.92 ppm, with only two studies exceeding 1.30 ppm. Conversely, soy-based formulas demonstrate values ranging from 0.13-1.11 ppm. In conclusion, the observed variability in fluoride levels in infant formulas is ascribed to the choice of the water source employed in the preparation process. This underscores the paramount importance of meticulously adhering to recommendations and guidelines provided by healthcare professionals concerning the utilization of these formulas and their meticulous reconstitution.

Fluoride Content of Ready-to-Eat Infant Foods and Drinks in Australia

The use of fluoride is effective in preventing dental caries. However, an excessive intake of fluoride leads to dental fluorosis, making it necessary to regularly monitor the fluoride intake especially for infants. There is hitherto a lack of information on fluoride content in infant foods from an Australian perspective. Therefore, this study aims to estimate the amount of fluoride content from a range of commercially available ready-to-eat (RTE) infant foods and drinks available in Australia. Based on an external calibration method, potentiometry involving a fluoride ion selective electrode and a silver|silver chloride reference electrode was conducted to analyse the fluoride content of a total of 326 solid food samples and 49 liquid food samples in this work. Our results showed an overall median (range) fluoride content of 0.16 (0.001-2.8) µg F/g of solid food samples, and 0.020 (0.002-1.2) µg F/mL of liquid food samples. In addition, ~77.5% of the liquid samples revealed a fluoride content < 0.05% µg F/mL. The highest variation of fluoride concentration (0.014-0.92 µg F/g) was found in formulas for ≥6 month-old infants. We have attributed the wide fluoride content variations in ready-to-eat infant foods and drinks to the processing steps, different ingredients and their origins, including water. In general, we found the fluoride content in most of the collected samples from Australian markets to be high and may therefore carry a risk of dental fluorosis. These results highlight the need for parents to receive appropriate information on the fluoride content of ready-to-eat infant food and drinks.

Black Tea Source, Production, and Consumption: Assessment of Health Risks of Fluoride Intake in New Zealand

In countries with fluoridation of public water, it is imperative to determine other dietary sources of fluoride intake to reduce the public health risk of chronic exposure. New Zealand has one of the highest per capita consumption rates of black tea internationally and is one of the few countries to artificially fluoridate public water; yet no information is available to consumers on the fluoride levels in tea products. In this study, we determined the contribution of black tea as a source of dietary fluoride intake by measuring the fluoride content in 18 brands of commercially available products in New Zealand. Fluoride concentrations were measured by potentiometric method with a fluoride ion-selective electrode and the contribution of black tea to Adequate Intake (AI) and Tolerable Upper Intake Level (UL) was calculated for a range of consumption scenarios. We examined factors that influence the fluoride content in manufactured tea and tea infusions, as well as temporal changes in fluoride exposure from black tea. We review the international evidence regarding chronic fluoride intake and its association with chronic pain, arthritic disease, and musculoskeletal disorders and provide insights into possible association between fluoride intake and the high prevalence of these disorders in New Zealand.

Fluoride levels in UK infant milks

AIM

To provide a comprehensive report of fluoride concentration in UK infant milks and estimate their contribution to daily fluoride intake.

METHODS

A total of 60 formula milk products available commercially or within a hospital environment were analysed, along with eight pasteurised cow's milk samples. Formula milk products requiring preparation were reconstituted with fresh Leeds tap water (0.02 ppmF). Fluoride concentration was measured for all products directly using an ion selective electrode after addition of low-level total ionic strength adjustment buffer.

RESULTS

The overall median fluoride concentration for the 68 infant milks was 0.025 ppmF, with a wide range of 0.002-0.282 ppmF. Analysis revealed variation between composition and manufacturer, in addition to differences between measured and labeled fluoride concentration. Although all products contained low fluoride concentration, the fluoride concentrations for formula milks used within the hospital setting (0.029 ppmF) were statistically higher in comparison to the commercial formula milk (0.016 ppmF) and cow's milk (0.017 ppmF) products. The daily fluoride contribution from infant milks was low; 0.0034 mgF/kg body weight per day was estimated between birth and 6 months of age, further decreasing as intake of infant milk decreased with age.

CONCLUSIONS

Fluoride concentration of the analysed infant milks is low, providing minimal contribution towards total daily F intake and alone are unlikely to pose a threat for the development of dental fluorosis.

Estimated dietary fluoride intake for New Zealanders

OBJECTIVES

Existing fluoride concentration and consumption data were used to estimate fluoride intakes from the diet and toothpaste use, for New Zealand subpopulations, to identify any population groups at risk of high-fluoride intake.

METHODS

For each sub-population, two separate dietary intake estimates were made--one based on a non-fluoridated water supply (fluoride concentration of 0.1 mg/L), and the other based on a water supply fluoridated to a concentration of 1.0 mg/L. Fluoride concentration data were taken from historical surveys, while food consumption data were taken from national 24-hour dietary recall surveys or from simulated diets.

RESULTS

Mean and 95th percentile estimations of dietary fluoride intake were well below the upper level of intake (UL), whether intakes were calculated on the basis of a non-fluoridated or fluoridated water supply. The use of fluoride-containing toothpastes provides additional fluoride intake. For many of the population groups considered, mean fluoride intakes were below the adequate intake (AI) level for caries protection, even after inclusion of the fluoride contribution from toothpaste. Intake of fluoride was driven by consumption of dietary staples (bread, potatoes),beverages (particularly tea, soft drinks, and beer), and the fluoride status of drinking water.

CONCLUSION

Estimates of fluoride intake from the diet and toothpaste did not identify any groups at risk of exceeding the UL, with the exception of infants (6-12 months) living in areas with fluoridated water supplies and using high-fluoride toothpaste. In contrast, much of the adult population may be receiving insufficient fluoride for optimum caries protection from these sources, as represented by the AI.