Aluminium contamination of powdered infant milks

There has been a long and significant history documenting the contamination of infant milks with aluminium and the consequent health effects of this, with aluminium toxicity associated with anaemia, bone disease and impaired neurological development (Fewtrell et al, 2011). Infant milks typically have 10 to 40 times more aluminium in them than breastmilk (Burrell and Exley, 2010; Chuchu et al, 2013). Warnings have been made to manufacturers over several decades in relation to aluminium toxicity and the vulnerability of developing infants to this, and therefore it could be assumed that levels in current infant milks would be low. However, in recent analyses of ready-to-feed infant milks, aluminium levels were found to vary from 155-422µg/litre, and in powdered milks from 106-756µg/litre, and there has been little change in content despite calls for a reduction (Chuchu et al, 2013). A recent analysis of specialised infant milks reported that the aluminium content of ready-to-drink preterm formulas ranged from 49.9 to 249.4 µg/litre. The aluminium content of powdered formulas for allergies ranged from 0.35 to 3.27µg/g which would be equivalent to about 32-385 µg/litre (Redgrove et al, 2019).

Soya protein based infant formula and pre-term infant formula have typically been found to have the highest amounts of aluminium (Burrell and Exley, 2010) and more recent analyses show that soya-based milks remain the highest, although all infant formula, follow-on formula and growing-up milks tested were contaminated with aluminium (Chuchu et al, 2013). Products are likely to be contaminated with aluminium from processing equipment and packaging, and a lack of progress in reducing this contaminant suggests that manufacturers do not consider it to be a health issue, despite evidence of both immediate and delayed toxicity in infants, especially pre-term infants. A recent study of pre-term infants fed intravenous fluids which were high in aluminium showed both impaired neurological development at 18 months and reduced bone mass at 13-15 years, and although there is likely to be much greater toxicity associated with intravenous administration of fluid, these findings suggest that significantly more should be done to reduce intakes (Fewtrell et al, 2011). EFSA considered aluminium toxicity in 2008 (EFSA, 2008) and suggested that 3 month old infants were typically exposed to aluminium at around 0.6-0.9mg/kg bw/week and 0.75-1.1mg/kg bw/week for soya formula, but acknowledged that the concentration in some formula brands was four times higher and that intakes could frequently exceed the current tolerable weekly intake of 1mg/kg bw/week. Breastfed infants are exposed to less than 0.07mg/kg bw/week.

Another study of milks in the UK in 2001 (Ikem et al, 2002) also reported that in some cases the amounts of aluminium, barium and thallium in infant milks exceeded stipulated water contamination levels, and again that soya protein based infant formula had higher aluminium contents than other formula, as did some milks made with partially hydrolysed protein.

Recent evidence suggests that levels of aluminium are higher in milks that are sold ready-tofeed in plastic bottles where the seal between the cap and the product is made of aluminium, and long-life cartons are also composed of packaging which has an aluminium foil central layer. However, variations between products with similar packaging means that there must be other sources of contamination (Chuchu et al, 2013). It appears that manufacturers have not addressed issues relating to aluminium contamination and we believe precautionary practical solutions to this public health issue should be sought.

References

Burrell SM, Exley C (2010). There is (still) too much aluminium in infant formulas. BMC Pediatrics, 10, 63.

Chuchu N, Patel B, Sebastien B, Exley C (2013). The aluminium content of infant formulas remains too high. BMC Pediatrics, 13, 162-167.

European Food Safety Authority (2008). Intake of aluminium from the diet. The EFSA Journal, 754, 1-34.

Fewtrell M, Edmonds CJ, Isaacs E, et al (2011). Aluminium exposure from parenteral nutrition in preterm infants and later health outcomes during childhood and adolescence. Proceedings of the Nutrition Society, 79, 299-304

Ikem A, Nwankwoala A, Odueyungbo S, et al (2002). Levels of 26 elements in infant formula from USA, UK and Nigeria by microwave digestion and ICP–OES. Food Chemistry, 77, 439- 447.

Redgrove J, Rodriguez I, Mahadevan-Bava S, Exley C (2019). Prescription infant formulas are contaminated with aluminium. Int J Environmental Research and Public Health, 16, 899- 906

Cadmium contamination of infant milks

It is suggested that long-term excessive intakes of cadmium can cause adverse effects on kidney function and bone mineralisation (Ljung et al, 2011). Little is known about early-life exposure to cadmium, and associated adverse effects, although absorption appears to be higher in infants than in adults (Kippler et al, 2010). Calculated weekly intakes of cadmium in the study by Ljung et al, varied between 0.10 and 1.5g/kg bw at 6 weeks of age, depending on the type of infant formula consumed, compared to 0.06g/kg bw in breastfed babies. Recent studies from rural Bangladesh reported elevated urinary cadmium concentrations in 3 month old infants, indicating high rates of intestinal absorption, probably because of the immature regulation of the transport system for divalent metal ions, and it is likely that the developing kidney is particularly susceptible to cadmium, as both glomerular and tubular functions continue to develop until 2 to 3 years of age (Sekine and Endou, 2009). It has also been suggested that cadmium has oestrogen-like effects in the case of early-life exposure (Johnson et al, 2003).

References

Johnson MD, Kenney N, Stoica A, et al (2003). Cadmium mimics the in vivo effects of estrogen in the uterus and mammary gland. Nature Medicine, 9, 1081-1084

Kippler M, Hoque AM, Raqib R, et al (2010). Accumulation of cadmium in human placenta interacts with the transport of micronutrients to the fetus. Toxicology Letters, 192, 162-168.

Ljung K, Palm B, Grander M, Vahter M (2011). High concentrations of essential and toxic elements in infant formula and infant foods – a matter of concern. Food Chemistry, 127, 943- 951.

Sekine T, Endou H (2009). Children’s toxicology from bench to bed – drug induced renal injury (3): Drug transporters and toxic nephropathy in childhood. The Journal of Toxicological Science, 34 (suppl 2), SP259-SP265

 Process contaminants from oil refining in infant milks

There has been recent concern that formula fed infants may be exposed to harmful levels of Glycidyl fatty acid esters (GE) and 2- and 3-monochloropropanediol (2-MCPD and 3-MCPD) and their fatty acid esters. These substances are formed when palm oils and fats and other vegetable oils are heated to temperatures in excess of 200°C during the refinement process. These potentially harmful substances have subsequently been identified in a range of oils and fats and foods that are made from them, including infant and follow-on formula milks. A recent study conducted by the Dutch National Institute for Public Health and the Environment found that samples of powdered infant formula contained significant amounts of 3-MCPD, although the levels varied widely between different products (RIVM, 2016). The European Food Safety Authority (EFSA) panel on Contaminants in the Food Chain (CONTAM) recently delivered a scientific opinion on the risks to human health posed by the presence of these contaminants in food. Based on evidence from animal studies the CONTAM panel concluded that GE is potentially genotoxic and carcinogenic and that 3- MCPD can cause kidney damage. There was insufficient data available to come to any conclusions on the toxicity of 2-MCPD (EFSA, 2016).

3-MCPD was first identified in the late 1970's and since then, its presence has been monitored in specific foods where high levels have been reported. In 2001 the Scientific Committee on Food set a safe tolerable daily intake (TDI) for 3-MCPD of 2.0 µg/kg/bw per day (SCF, 2001). Based on the available evidence the CONTAM panel lowered the TDI to 0.8 µg/kg/bw per day (EFSA , 2016). From the dietary surveys included in their study, EFSA found that younger age groups were at greatest risk of exposure to 3-MCPD. In over half of the dietary surveys reviewed, the average exposure for infants, toddlers and other children up to ten years of age was at or above TDI. For infants who were exclusively formula fed, average exposure was more than three-times TDI at 2.4 µg/kg/bw per day and for those with greatest exposure more than four times TDI at 3.2µg/kg/bw per day. The CONTAM panel concluded that this level of exposure was cause for concern. It is worth noting that the TDI is set with a generous safety margin far in excess of the levels identified as causing harmful effects in animal studies.

Due to the potentially genotoxic and carcinogenic nature of GE, TDI are not set and the risk to consumers is expressed as a Margin of Exposure (MoE). The higher the MoE, the lower the level of concern and vice versa. An MoE of lower than 25,000 was considered by EFSA, to be a health concern. EFSA estimated a MoE for infants aged 0-3 years with average exposure to GE ranged from 11,300 to 25,500. Infants who were exclusively fed on infant formula were at significantly greater risk. The MoE for average exposure was around 5,400 and for high exposure 2,100. EFSA have said that in infants’ MoE estimates were particularly low due to the contribution of glycidyl esters from infant formula and also point out that there were uncertainties involved in the setting of the level of MoE at 25,000.

The CONTAM Panel recommended that all potentially contaminated foods be included in future monitoring of 3-MCPD, 2-MCPD and GE. EFSA's scientific opinion was used to inform EU food safety regulators’ considerations on how to manage the risk of exposure to these substances in foods. In 2020, the EU issued regulations setting maximum levels for the presence of GE and 3-MCPD and its fatty acid esters in vegetable, marine and fish oils and fats placed on the market for the final consumer or for use as an ingredient in food. Because of the health concern for infants, toddlers and young children, stricter maximum levels were set for oils and fats destined for the production of baby food and processed cereal-based food for infants and young children. Taking into account the possible exposure to GE of infants solely fed on infant formula, a specific strict maximum level for infant formula, followon formula and foods for special medical purposes intended for infants and young children has been established. Regulation (EU) 2020/1322 stipulates a maximum level for GE of <50ug/kg in infant and follow-on formula milk powder and foods for special medical purposes intended for infants and young children, and a lower maximum level of <6ug/kg for liquid formulations (EFSA, 2020). A maximum level for 3-MCPD and fatty acid esters of 125ug/kg in infant and follow-on formula milk powder and foods for special medical purposes intended for infants and young children and a lower maximum level of 15ug/kg for liquid formulations has been established. The regulations can be found here: https://www.legislation.gov.uk/eur/2020/1322/introduction.

Given these concerns, the removal of palm oil from infant milks and baby foods would be a prudent response from industry. Some brands of infant milk in the UK do not use palm oil in their products, but the main brands (Aptamil, Cow & Gate, Hipp Organic and SMA) do still use palm oil in some or all of their products. You can find out which oils are used in infant milks on the UK market from the individual product datacards at www.infantmilkinfo.org.

References

European Food Safety Authority (2016). Scientific opinion on risks for human health related to the presence of 3- and 2-monochlropropanediol (MCPD), and their fatty acid esters, and glycidyl fatty acid esters in food. EFSA Journal, 14 (5), 4426. Available at https://www.efsa.europa.eu/en/efsajournal/pub/4426

Rijksinstituut voor Volksgezondheid en Milieu (National Institute for Health and Environment) (2016). Preliminary assessment of dietary exposure to 3-MCPD in the Netherlands. Available at http://www.rivm.nl/en/Documents_and_publications/Scientific/Reports/2016/april/Preliminary _assessment_of_dietary_exposure_to_3_MCPD_in_the_Netherlands

 Uranium contamination of infant milks

There has been some concern that infant formula made up with some waters could contain high levels of uranium, which is thought to have potential toxic effects on kidney function. The World Health Organization (WHO) has set a guideline maximum level of 15µg/litre for uranium in water, but there is some concern that giving infants infant formula made up with water that has 15µg/litre could result in infants under 6 months consuming up to four times the tolerable dietary intake (TDI) also set by WHO (Committee on Toxicity, 2006). At the present time there are not thought to be any health concerns to infants related to uranium in infant milk, but COT (the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment) acknowledges that it has little data in this area and the impact of these intakes is uncertain. Some bottled waters may have high levels of uranium and so it is important that, if a bottled water is used to make up a feed, the bottled water should specify that it is suitable for infant formula.

References

Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (2006). COT statement on uranium levels in water used to reconstitute infant formula. Available at http://cot.food.gov.uk/pdfs/cotstatementuranium06.pdf