Phytoestrogen Content of Foods of Animal Origin

Some consumers are very concerned about possible harmful plant-based substances that might be in the meats they eat.  For instance gluten is a protein in grains.  All grains contain proteins but people with celiac disease and other gluten allergies only react to the form of gluten found in wheat, spelt, kamut, triticale, barley, and rye.  Therefore those consumers are concerned that gluten might be in the meat of animals that were fed those grains.  In addition, other consumers are very concerned about phytoestrogens and lignans in soy being in the meats of animals fed soy.

When animals eat wheat and soy, their digestive systems breakdown the gluten, phytoestrogens, and lignans.  The end result is the same for gluten and lignans as will be found in the example below for phytoestrogens.

Phytoestrogens, secondary plant metabolites, are found in a wide variety of plant-based foods, including seeds, whole grains, legumes, fruit, and vegetables.  When plants are ingested, they are metabolized by intestinal bacteria.  Therefore if we eat any animal that lives on these plants, they will have ingested phytoestrogens.  But their digestive systems breakdown most of the material and their concentrations are much lower than eating the plants directly.

The scientific report in the link below shows that all foods analyzed contained phytoestrogens and most foods (except for fish, seafood, and butter) contained mammalian phytoestrogens (enterolignans and equol). This study is the first comprehensive report of phytoestrogen content of foods of animal origin and it provides an accurate estimation of exposure to dietary phytoestrogens.  There is an extensive list of animal food products in the report with their actual concentrations of phytoestrogens.  As the data illustrates, the concentrations of phytoestrogens in meat is far lower than in the plants the animals may have eaten.  For instance the phytoestrogens in soy infant formula are 1,000 times higher than in meats.  To see the entire report click HERE.