What are the disadvantages of eating too much soy?

Author Name
Answered by: Faith, An Expert in the Nutrition - General Category

Soy, which is also known as soybean, is a legume whose origin is East Asia. Soy comes in various sizes and colors including black, yellow, green and brown. According to a study by University of Maryland Medical Center, the legume has 40% protein content, 20% oil and 35 % carbohydrates. Nowadays, soy is an important part of every household’s diet. However, it is worth noting that farmers in the United States first grew soybean as food for their cattle. Another interesting fact is that soy oil is used to make ink that is used to print textbooks and newspapers. It has one of the highest quantities of lean proteins so you should include it in your diet. However, there are a number of disadvantages of eating too much soy.


The protein found on soy is said to be highly allergenic. If you eat too much soy and you are allergic to it, you may experience such symptoms as a rash, diarrhea, constipation, difficult breathing and in severe cases organ failure. The information about the allergic effect of soy is based on a nutrition journal, by American Society for Nutrition (ASN).


Soy is a rich source of isoflavones. According to a study by lowa State University, a whole (dry) soy contains about 200 milligrams of isoflavones per 100 gram serving. Isoflavones are polyphenolic compounds or phytoestrogens which are capable of exerting estrogen-like effects on the human body. Isoflavones are said to lower the testosterone levels in men thereby causing low libido and infertility. Isoflavones are also very dangerous especially to those with thyroid related problems. This is because they lower the amount of iodine that is found in the body. Consequently, the thyroid under-functions and this leads to hyperthyroidism. The phytoestrogens in soy also interfere and reduce the efficacy of drugs used in the treatment of osteoporosis and breast cancer. Thus, if you are on cancer treatment, you should consult your doctor before eating soy.


This is a naturally occurring substance commonly found in foods that are plant based. Based on information provided by the National Soybean Research Laboratory (NSRL), oxalate is said to contribute to the formation and building up of kidney stones. Some people are more at risk of developing oxalate kidney stones. This group of people should reduce the amount of soy in their diet or eliminate it altogether.

Mineral Content

Soy contains 1797 milligrams of potassium and 704 milligrams of phosphorus. The amount of phosphorus is more than the recommended daily allowance. The levels potassium and phosphorus found in soy are considered high as those found in red meat. They are said to increase your risk of developing kidney disease. This information is based on a research carried out by the National Kidney and Urologic Disease Information Clearinghouse (NKUDIC).


1.     Indiana Farmers Feed US: Soybeans


2.     Journal of Nutrition: Soy Protein Allergy: Incidence and Relative Prevalence


3.     Linus Pauling Institute: Soy Isoflavones


4.     USDA-Iowa State University Database on the Isoflavone Content of Foods, Release 1.3 - 2002


5.     National Kidney and Urologic Diseases Information Caringhouse: Kidney Stones in Adults


6.     National Soybean Research Laboratory: Soy Benefits


7.     Soybean.org: Soybean Nutrition Facts


Author Name Like My Writing? Hire Me to Write For You!

Related Questions