To eat soy or not to eat soy seems to be the question on many of our patients’ minds these days. On one hand, we have extensive studies acknowledging soybean as a miracle food with high nutritional value and a natural protection against a host of diseases. On the other hand, critics argue that soy protein isolates are dangerous, linking soy iso flavones with breast cancer, allergies, thyroid disease and infertility. Both sides of the story are heated and ironically well researched and extensively promoted.
So, what do we infer from all these conflicting schools of thought about the potential benefits and dangers associated with intake of soy and soy products?
In this article, I intend to provide you with the facts around soybean and its myriad effect on our body functions with relevant scientific data and ways to incorporate soybean into our daily diets effectively.
Soybean as food- the nutritional profile The soybean is a versatile legume which can be eaten raw, soaked, boiled, roasted, and fermented or its seeds ground into flour. Soybean can be flaked, its oil extracted and even the isoflavones and protein can be isolated and added to nutritional supplements. Soy beans contain high amounts of plant protein and are also a rich source of calcium, iron, zinc, phosphorus, magnesium, B-vitamins, omega 3 fatty acids and fiber. Early oriental and eastern texts prescribed soy as not only good for digestion and detoxification, but also for maintenance of good health and general well being. Soya has been shown to help lower cholesterol, triglycerides and regulate blood sugar levels while playing a significant role in relieving menopausal symptoms.
Soy and heart disease Results of various clinical studies demonstrate that a diet with significant soy protein reduces Total Cholesterol, LDL cholesterol (the “Bad” cholesterol) and Triglycerides, confirming the benefits of soy in heart disease management. As a result of these findings, in 1999, FDA authorized a health claim that foods low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease. Researchers compared soy protein with other proteins such as milk and meat, and found that soy protein can lower total and LDL-cholesterol levels, qualifying it as a healthy replacement for meats or other foods high in saturated fat and total fat.
Soy and menopauseSoybean is rich in iso flavones (phyto nutrients), the most effective in relieving menopausal symptoms being genistein and daidzein. Because of its iso flavone compounds and high antioxidant content, whilst being low in glycemic index, soy and soybeans may help prevent menopausal symptoms, particularly vaginal dryness, night sweats and hot flushes.
Soy and osteoporosis Many soy foods like soymilk and soy paneer (tofu) are naturally high in calcium. In addition, soy also contains magnesium and boron, which are important co-factors of calcium for good bone health.
So, you may ask why the controversary??The problem lies in the
–a) Iso flavones, a “phyto estrogen,” and goitrogen (a substance that promotes thyroid enlargement and goiter formation) that occur naturally in the soybean. Phyto estrogens are estrogen-like compounds and are shown to act most favorably when they can compete with estrogen, already present in the body(in pre menopausal women).Because it has been assumed that menopause is associated with a loss of estrogen (based on blood levels), many researchers have assumed that soy may fail to offer a protective effect in postmenopausal women and may even produce an estrogenic effect, hence increasing one’s risk for breast cancer(studies show that the estrogen levels are highest in breast tissues during menopause). These soy phyto estrogens have also been shown to be anti-thyroid agents, causing sluggish thyroids, and weight gain.
b) Presence of anti nutrients such as trypsin inhibitors, hemaglutinin and phytic acid. Trypsin inhibitors interfere with protein digestion and the presence of phytate layer makes soybean difficult to digest and assimilate.
Undoubtedly, we need extensive research on human subjects but in light of the current evidence, moderate dietary intake of soy—two or more servings of soy foods twice or thrice a week (providing 30-60mg of iso flavones per day)—appears to be a reasonable level of intake, especially for women with history of breast cancer.
My recommendation is first and foremost to listen to your body. If you do well with soy products, chances are you are metabolizing and tolerating them effectively. If you react negatively to soy or have difficulty in digesting the soy products, avoid it. Soy is a great food which is high in nutritional value and also a good source of fiber, B vitamins, calcium, and omega-3 fatty acids. It is thus suggested that you may go ahead with your soy foods but only in moderation and as a part of an otherwise healthy and balanced diet.
I would like to add that whilst there’s no need to be alarmed, in the same way avoid getting overly excited about the miraculous potentials.
Soy is what it is — a food, not medicine and if eaten as part of a healthy diet won’t expose us to any grave risk and would surely benefit our health.