Most Infant Formula Trials Lack Transparency

Kate Johnson

October 25, 2021

Baby formula trials are not reliable and have an "almost universal lack of transparency" which could undermine breastfeeding, according to the results of a systematic review published in BMJ. The findings underscore the need for significant change in the way such trials are conducted and reported, concluded lead author Bartosz Helfer, PhD, of the National Heart and Lung Institute at Imperial College London and the University of Wroclaw (Poland) Institute of Psychology and his coauthors. Citing a high risk of bias, selective reporting, and "almost universally favourable conclusions," the international team of investigators suggested "some trials might have a marketing aim and no robust scientific aim," concluding "much of the recent information generated about formula products might be misleading."

The review included a detailed evaluation of 125 trials published since 2015, that compared at least two formula products in 23,757 children less than 3 years of age. The trials were evaluated for how they were conducted and reported, with specific attention paid to their risk of bias and risk of undermining breastfeeding.

Using the Cochrane risk-of-bias assessment 2.0 (ROB2), the analysis found that risk of bias was high in 80% of trials "usually because of inappropriate exclusions of participants from the analysis, and selective reporting," the investigators noted. "This lack of transparency was complemented by favourable conclusions in more than 90% of recent trials, and evidence of publication bias in recent superiority trials."

When conflict of interest was assessed, the analysis showed 84% of the trials received support from the formula milk industry, and of these, 77% had at least one author affiliated with a formula company. Overall, only 14% of trials had a low level of conflicts of interest according to the investigators' definition "that the main source of funding had no commercial interest in the outcome of the trial and all of the authors of the study declared no financial ties to an entity with a commercial interest in the outcome of the trial."

The investigators also noted that, by providing free formula to parents of breastfed or mixed-fed infants, many of the trials may have contravened the International Code of Marketing of Breast-milk Substitutes — an international agreement used to protect breastfeeding and limit the marketing of formula. "Claims arising from formula trials can contribute to formula marketing by narrowing the perceived benefits of breast milk over formula for consumers," they wrote, calling for "improved oversight, conduct, and reporting of formula trials to ensure they provide a rigorous evidence base to inform nutrition in infants and young children."

Asked to comment, Jennifer L. Pomeranz, JD, MPH, who was not involved in the study, told this publication the findings are "very concerning." Pomeranz of New York University's School of Global Public Health, recently reported similar issues in an analysis of baby formula websites. "Infant formula labels in the US are adorned with a plethora of unsupported health and nutrition-related claims, including unregulated structure/function claims and breast milk comparison claims," she said. "Moreover, infant formula marketing uses these claims to convince new parents that infant formula is necessary and even better for their infants than breast milk. Our research indicates that parents believe the popular claims made by formula companies and some even believe that infant formula is better for their child's development than breast milk. If these claims are based on trials with no robust scientific basis, as the study suggests might be the case, then they are certainly false, deceptive, unfair, and misleading."

Pomeranz called for the Food and Drug Administration's regulation of infant formula labels, adding that "Congress should grant the FDA the explicit authority to require evidence to support structure/function claims on infant formula and prohibit breast milk comparison claims.... The Federal Trade Commission and state attorneys general should bring actions against infant formula manufacturers for false and deceptive claims made in marketing materials," she added.

Jack Newman, MD, another expert not involved in the study told this publication that the findings show how most formula studies "are essentially another marketing tool of the formula companies and are aimed at a very susceptible audience — healthcare professionals." According to Newman, chief pediatrician and founder of the Newman Breastfeeding Clinic in Toronto and a former UNICEF consultant for the Baby Friendly Hospital Initiative, "healthcare professionals often like to believe they are immune to formula company marketing — yet this study shows that, even if they believed they were relying on scientific evidence, they were in fact being influenced toward formula feeding by studies that are biased, unreliable, and designed to promote formula to begin with."

However, Stewart Forsyth, MD, honorary professor in child health, at the University of Dundee (Scotland) and retired consultant pediatrician and medical director at NHS Tayside, Scotland, cautioned that this is a delicate issue on all sides of the debate. The possibility of bias "is a potential issue with all aspects of research but is heightened in relation to infant feeding research because of the longstanding conflict involving the World Health Organisation, breastfeeding activist groups, and the infant formula industry, and as a consequence, all three of these organisations frequently resort to overinterpreting the data to favour their arguments," he told this publication. An example is the suggestion that formula trials might contravene the International Code of Marketing of Breastmilk Substitutes because they provide free formula to participants. "Since when do participants in a research study have to pay for the intervention that is being studied?" he asked.

Stewart advised three key considerations "to mitigate the damaging effects that this type of inappropriate and misleading information may have on policy, practice, and engagement with parents." First, it must be acknowledged that there is need for "a product that will provide a safety net for infants who are not offered breast milk," he said. "It has been argued that to determine optimum nutrient requirements in infants and young children collaboration with nutrition companies is required." Second, "all researchers need to comply with regulations relating to scientific methods, ethical standards, and financial diligence." And finally, "there needs to be more effective planning and coordination of research activities to ensure that lessons are learned from the many studies that have design and methodological deficiencies."

The study was funded by Imperial Health Charity. Pomeranz and Newman reported no conflicts of interest. Forsyth has undertaken consultancy work with governments, healthcare institutions, academia, and industry and has received research grants and honoraria from governments, charitable organizations and industry, including infant formula companies.

Senior author Robert J. Boyle, MBChB, MRCP, PhD, received personal fees from Cochrane, DBV Technologies, and Prota Therapeutics, and from expert witness work in cases of food anaphylaxis and class actions related to infant formula health claims, outside the submitted work, and received personal fees from Public Health England as a member of the UK Nutrition and Health Claims Committee and the Maternal and Child Nutrition Subgroup of the Scientific Advisory Committee on Nutrition. Coauthor Jo Leonardi-Bee, MSc, PhD, received fees from Danone Nutricia Research and the Food Standards Agency, outside of the submitted work.

BMJ. 2021;375:n2202. Full text

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