Objective: Well-meaning but inadequately informed parents may perceive plant-based beverages such as soy beverages (SB) or rice beverages (RB) as an alternative to infant formula. Manganese (Mn) is an essential mineral nutrient found at high levels in plants such as soy and rice. Excessive Mn exposure increases the risk of adverse neurological effects.
Methods: We analysed, by atomic absorption spectrometry, the Mn content of 36 SB, 5 RB, 6 evaporated milks (EM), 14 soy-based infant formulas (SF) and 16 milk-based infant formulas (MF), obtained from commercial outlets in Ottawa, Canada.
Results: SB had the highest levels of Mn (16.5 +/- 8.6 micro g/g dry wt, mean +/- s.d.), followed by RB (9.9 +/- 1.7 micro g/g dry wt). Mn levels of individual SB/RB ranged from 2 to 17 times the mean Mn content of SF (2.4 +/- 0.7 micro g/g dry wt) and 7 to 56 times that of MF (0.70 +/- 0.35 micro g/g dry wt). EM contained very little Mn (0.02 +/- 0.03 micro g/g dry wt). Calculated mean Mn intakes from SB/RB by infants up to 6 months of age, assuming complete substitution of these products (0.78 L/day), approached the Tolerable Upper Intake Level (UL) for 1-3 year olds (no UL for Mn is available for infants under 1 year of age). Expressed as micro g Mn/100 kcal, SB/RB exceeded the range derived from ULs and typical energy intakes of 1-3 year olds.
Conclusions: SB/RB should not be fed to infants because they are nutritionally inadequate and contain Mn at levels which may present an increased risk of adverse neurological effects if used as a sole source of nutrition.