The Misunderstood Soybean

Last edited, 13 April 2020.

Soybean has been part of the human diet for almost 5,000 years, and yet it is still such a misunderstood food…

Soy is rich in protein, dietary fiber, low in saturated fat, cholesterol-free and has excellent source of phytochemicals and minerals like calcium, iron and phosphorus.

It has protein 2 times that of meat, 4 times that of chicken eggs and 12 times that of cow’s milk and it provides all the essential amino acids needed for human health!

It is a much better choice of protein compared to protein derived from meat and milk as human body cannot break down animal protein effectively.  Excess animal protein which remains undigested can cause allergies.  Diets high in animal protein can also cause calcium to be excreted through urine and increases the risk of osteoporosis.  And unlike animal protein, soy protein will not burden or damage our kidneys.
Even so, there are reports claiming that the phytoestrogens in Soy could cause cancer, have adverse effects on men and some other endorcrine related problems.
The truths…

What is Phytoestrogens

Phytoestrogens are found in almost all plant foods, especially in legumes, vegetables and nuts.  Soy, winter melon, broccoli, cabbage, apple, sesame seed, pistachio, almond, walnut are examples of plant foods containing phytoestrogens.
Examples of some phytoestrogens are isoflavones, lignans, coumestans and stilbenes.

Phytoestrogens are different from aninal-derived estrogens.  As phytoestrogens are natural plant nutrients, they have no side effects and are beneficial to health.

Do phytoestrogens cause cancer?

Phytoestrogens actually prevent cancer!  They lower the risk of estrogen-dependent cancers such as breast cancer.  The phytoestrogens actually fill the estrogen receptor sites on cells, keeping cancer-causing estrogen from promoting growth of malignant cells.  So unlike consuming estrogen pills, soy phytoestrogens are wholesome, have gentle estrogenic effects and will not cause any ill effects.

Do phytoestrogens have adverse effects on men?

Not at all!  Research studies have shown that phytoestrogens do not affect bioavailability and concentration of free testosterone in the male.  Instead, phytoestrogen-rich diets help in preventing prostate cancer.

Will consuming Soy affect Gout condition?

A myth is circulating that gout patients should avoid soybeans and soy products especially soy milk as they are rich in purine, highly hydrophilic and increases after soybeans are ground into soy milk.  This is however not true.

Purine occurs naturally in the human body, the main compnent of DNA and RNA.  It is essential for providing energy, regulating metabolism and forming coenzymes.  Due to aging cells or excess consumption of purine-rich foods such as organ meats and seafood, there can be excess purines in the body.  When body breaks down purines, uric acid is produced.  If the excess uric acid is not removed in time or uric acid excretion mechanism degenerates, high levels of uric acid in blood will cause uric acid crystals to form in joints, tissues and kidneys.  This in turn will cause our immune system to attack against these crystals as they do not belong there.  This immune reaction causes inflammation and induces gout.

However, the amount of purine in soy is moderate.  It is lower than purine-rich foods such as organ meats.  Also excess water is removed during the manufacturing process of soy products such as tofu and excess purines are removed with it.

Moreover, estrogens help inhibit formation of uric acid.  Compared to fish, meat, seafood and freshwater delicacies, soy products are relatively safer and ideal sources of protein.
A recent findings (published in The Straits Times dated 7 May 2015) by the Singapore Chinese Health Study at the NUS Saw Swee Hock School of Public Health that Soy is not associated with higher risk of gout.  The results confirm with six other studies done in Japan and Taiwan.  This further confirms that consuming soy does not increase uric acid in one’s blood. The study also suggested that red meat and poultry consumption was linked to a higher risk of gout.

Which plant foods are rich in phytoestrogens?

Food high in phytoestrogens are chinese yam, sage, raspberry and soy.

Other goodness about Soy

  • It regulates estrogen levels by preventing the body’s estrogen levels from being too low or high.  Thus it improves complexion, alleviate menstrual discomfort, delay onset of menopause and prevent hormone-related diseases, like breast, endometrial, and prostate cancer.
  • Due to declining estrogen levels for middle-aged and elderly women, they are at risk of osteoporosis. Phytoestrogens like isoflavones fill estrogen receptor sites on bone cells to reduce bone loss and at the same time increase the body’s absorption of calcium and increase bone density to improve bone health.
  • Soy phytoestrogens lower LDL cholesterol while maintaining HDL cholesterol, inhibiting the hardening of arteries to prevent coronary heart disease.