The question
Does soy milk contain high estrogen levels? Is it unsuitable for men?
The answer
Soy beverages are made from soybeans, which contain natural compounds called isoflavones.
Soy beverages will vary in isoflavone content depending on how they are made. Isoflavones behave like very, very weak forms of the body's own estrogen. Isoflavones compete for the same place on cells that estrogen does. That means isoflavones can affect the action of estrogen in your body, but not increase the level of estrogen.
For example, since isoflavones can bind to estrogen receptors on breast cells, they prevent a woman’s own, more potent, estrogen from taking that spot. Some of the risks of excess estrogen, including breast and uterine cancer, are thought to be lowered in this way.
Yes, soy beverages are suitable for men too! In fact, a study conducted in more than 12,000 Californian men found that those who drank a soy beverage daily, compared to those who never drank it, were 70 per cent less likely to develop prostate cancer. It’s thought that isoflavones can help keep testosterone levels in check (prostate cancer cells feed off testosterone). Soy beans also contain other phytochemicals that have cancer-fighting actions.
Not all soy beverages are created equal. To choose a healthier product, read nutrition the label. Per 250 ml serving, look for 8 to 10 grams of protein. You also should limit refined sugar.
Flavoured soy beverages can have as much as 21 grams of sugar (5 teaspoons worth) per serving. Unflavoured versions contain added cane juice or rice syrup which adds 5 to 10 grams of sugar per 250 ml serving. Unsweetened products have no more than 2 grams of sugar per serving.
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