Chemicals in cow milk and soy beverages: Neurotoxicity and neuroprotection

Cow milk constitutes a fundamental component of the human diet. Along with high nutritional value, contains neuroprotective components, caseins, lactoferrin, phospholipids and tryptophan. However, due to the use of pesticides in agriculture, veterinary drugs in livestock, and the presence of other contaminants, cow milk is frequently contaminated by these chemicals posing a risk to human health, namely through neurotoxicity. Strategies to decrease these contaminants include detoxification via microorganisms. Concomitantly, increased consumption of plant-based protein to substitute animal sources has been seen globally, being soy beverages (SB) utilized as an alternative to cow milk. Soy products are almost equivalent to animal sources in protein quality, and moreover, soy isoflavones like genistein, daidzein and glycitein and saponins, as well as soy peptides, may play neuroprotective roles. Conversely, neurotoxic risks associated with the consumption of soy beverages also exist, mainly due to the presence of excess of manganese, mycotoxins and consequences of human interventions during cultivation, resulting in pesticide residues, and pollution of soils, namely with metals. Due to the neurotoxicity and bioaccumulation of these contaminants, the fact that both cow milk and soy beverages are routinely ingested by all ages, and represent key ingredients in many processed foods, including baby foods, strict surveying of their levels is suggested.