In the study, Gunter G. C. Kuhnle, Laure Thomas and colleagues point out that phytoestrogens have garnered increasing attention for their beneficial role in preventing several diseases, including osteoporosis, type-2 diabetes and certain cancers, reports Science Daily.
But much of the scientific research on these compounds has focused on their occurrence in plant-based foods, which has led to an underestimation of actual amounts people consume, the study says.
The researchers analyzed 115 foods of animal origin and found that all food groups studied contained phytoestrogens.
Isoflavones - one of the three major classes of these compounds - were considerably higher in soy-based foods. In fact, the amount of phytoestrogens in soy-based infant formula was more than 300 times higher than in normal infant formula.
In animal products, phytoestrogens are low when compared to foods containing soy, the paper notes, but the range is similar to that of many commonly consumed vegetables.