Soy: healthy protein or cause of avoidable harm?

Should pets eat soy / soya?

The origins of Soy date back to China, where it remained resident until around 1895 when the Japanese began importing it as a fertilizer. It was not imported into Europe until 1908, but had been used as a forage crop in America back in 1879, and was used as hay until the 1920’s, however the advent of World War II saw increased production, by the 60’s and 70’s America produced more than 75% of the Worlds’ Soy, mostly going into animal feed.

“The majority of the soybean crop is processed into oil and meal. Oil extracted from soybeans is made into shortening, margarine, cooking oil, and salad dressings. Soybeans account for 80 percent or more of the edible fats and oils consumed in the United States. Soy oil is also used in industrial paint, varnishes, caulking compounds, linoleum, printing inks, and other products. Development efforts in recent years have resulted in several soy oil-based lubricant and fuel products that replace non-renewable petroleum products.

Lecithin, a product extracted from soybean oil, is a natural emulsifier and lubricant used in many food, commercial, and industrial applications. As an emulsifier, it can make fats and water compatible with each other. For example, it helps keep the chocolate and cocoa butter in a candy bar from separating. It is also used in pharmaceuticals and protective coatings.

The high protein meal remaining after extraction can be processed into soybean flour for human food or incorporated into animal feed. Soybean protein helps balance the nutrient deficiencies of such grains as corn and wheat, which are low in the important amino acids, lysine and tryptophan.

Use of vegetable proteins for human consumption continues to expand in the United States. They can be used as meat and dairy substitutes in various items. Most people are aware of the use of soy proteins in baby formula, weight-loss drinks, sport drinks, and as a low-fat substitute for hamburger.

Soy flour and grits, made from grinding whole soybeans, are used in the commercial baking industry to aid in dough conditioning and bleaching. They have excellent moisture-holding qualities that help retard staling in bakery products.”

Soy has been utilised in pet foods now for a number of years as proximate analysis is up to 40% protein and 22% fat, being a legume it is not species appropriate for our carnivorous pets and is high in lectins, designed by nature to disrupt digestion and have been associated with diabetes, obesity, and cardiovascular diseases (Kalander, 2012). With America being the world leader in soy production it is worth noting that 91% of the soy produced in the United States is GMO.

GMO soy has been found to:

• kill baby rats in just 3 weeks
• stunt growth
• raise mortality rates
• induce sterility 
• produce mutations
• cause  DNA damage, abnormal sperm, blood changes, and damage to liver, kidney and testes
• produce malformations in pigs including ear atrophy, spinal and cranial deformations, hole in the skull, and leg atrophy. In one piglet, one eye was not developed; it had a single large one (cyclopia, a malformation observed in Argentine populations exposed to Roundup spraying). There were piglets without a trunk, with an “elephant tongue”, and a female piglet with testes. One malformed piglet had a swollen belly and the foregut and hindgut were not connected.
• be toxic to the normal metabolism
• produce a higher rate of severe stomach inflammation

The old adage “one mans’ food is another mans’ poison’ could not be more relevant.

For more information we recommend this article “Soy in Pet Foods: The Unwholesome Truth” by Pet Nutrition Blogger Rodney Habib

Turner, H.B. (2015) Soy: healthy protein or cause of avoidable harm? Healthful Dog 2[2]:112