Infant formula and solid baby food frequently contain fungus-derived hormones that have been shown to cause infertility in mammals, Italian researchers report.
Scientists at the University of Pisa report that as many as 28% of milk-based baby formulas they tested were contaminated with mycoestrogens.
They tested 185 formula samples and 44 samples of meat-based baby food from a total of 21 brands commonly sold in Italy.
Large family of fungi
The substances detected in the baby products included zearalenone and its derivatives, which come from Fusarium, a large family of fungi common in farm settings, they reported online in the Journal of Paediatrics.
Although zearalenone and related chemicals that resemble the hormone oestrogen have been linked to infertility in mammals, especially pigs, it's not clear whether babies exposed to the compounds through food or formula would be at risk for any reproductive problems later in life.
Previous research has shown that the body rapidly breaks down zearalenone into by-products that pose no health threat.
Still, the Italian researchers say their findings merit follow-up and ought to prompt closer scrutiny of baby formula and baby foods for the presence of these and other toxins.
"Our study shows the presence of mycoestrogens in infant food," Dr Francesco Massart, who led the study, told Reuters Health. "This is likely to have greater implications for infants and young children than for adults having a more varied diet."
Mycoestrogens such as zearalenone are a fact of life for commercial agriculture. They are present in crops like corn, wheat and soy that are used for both human consumption and animal feed. Cattle yards in the United States regularly use one such substance, alpha-zearalanol, as a growth stimulant for animals, although the European Union banned this practise in the mid-1980s.
The Italian group sought to determine whether zearalenone and similar chemicals might be making their way into infant foods. The answer was yes.
Dr Massart and his colleagues analysed 185 samples from 14 brands of infant formula containing cow's milk. They also tested 44 samples of baby foods, from seven brands, containing beef, chicken, turkey, calf, horse, rabbit, ham and lamb.
Zearalenone appeared in 17 (9%) of the formula samples, and two derivatives of the molecule, alpha- and beta-zearalenol, were present in about a quarter of the samples. Among the meat-based baby foods, the alpha-zearalenol derivative was present about a quarter of the samples.
Concentrations of mycoestrogens varied widely but in general, the levels detected were well below the World Health Organization's provisional maximum tolerable daily intake of 0.5 micrograms per kilogramme of body weight. Average concentrations of beta-zearalenol in infant formula were four times the recommended maximum, however.
Dr Massart acknowledged that many questions remain about the possible link between mycoestrogens and harm to humans. Still, he said, the findings should give pause to parents who use baby formula.
Long-term effects unknown
"Children, and in particular pre-term newborns, are potentially exposed to higher doses of mycotoxins during their early phases of life, but no one knows the long-term effects," he said.
Animal research and the few available human studies suggest the early mycotoxin exposures may affect human health, Dr Massart noted. "Specific studies should be initiated that allow the establishment of safe levels of zearalenone metabolites in feed materials and compounded feeds, particularly for infants and children of different ages, as they are considered to be the most sensitive to environmental chemicals."
Dr Gilbert Ross, a physician and medical director of the American Council on Science and Health, a New York-based advocacy group, disagreed. "Detecting something in food does not mean it's harmful," he said.
"Further, the detection methods found (the contaminants were present) at levels far too low to affect human health, including that of babies. As the authors themselves point out, the presence of these substances in food products are of 'little significance' because the body rapidly breaks them down and excretes them," Dr Ross said.
(Reuters Health/ March 2011)
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