1. Can act like a goitrogen – suppressing thyroid function
2. Contains “anti-nutrients” that can cause allergies, weight gain, digestive upset etc.
3. The “anti-nutrients” interfere with protein digestion and assimilation
4. Women taking either soy isoflavone tablets or a placebo for two years found no difference regarding changes in bone mineral density in the spine, hip or neck, while a significantly larger proportion of participants in the soy group experienced hot flashes.
5. Most soy is genetically modified
Should you eat soy?
Consuming fermented varieties is the healthy choice, these would include tempeh, miso, and soy sauce.
Shopping for a protein powder?
Buy other plant protein and protein powders like hemp, rice, pea, alfalfa, cranberry, artichoke, amaranth and spirulina.
One company that I know of (Jarrow) makes a fermented soy protein powder, so if you must do soy protein, make sure it is fermented.
Beware of Soy Lecithin.
None of the anti-nutrients are present in soy lecithin if it is high quality. Purified commercial lecithin is composed of pure lipid substances that also contain the mineral phosphorus. Collectively, these materials are referred to as phospholipids, or phosphatides. Soy lecithin is made up of 98% pure phosphatides with the remaining 2% being moisture and mineral ash. All parts of soy lecithin can be utilized in human biochemistry without toxicity, as long as it is non-GMO.
Choose rice, almond, coconut, oat, and flax milks instead.
Soy protein isolate is in a lot of “power bars”, so read the label!
Most “veggie burgers” contain a lot of soy, read the labels!
Many brands of chips, crackers and “rice cakes” sneak it in their recipes too, read the label!
Consume tofu and edamame on a limited basis. Buy only organic and non-GMO brands.
Photo courtesy of choosingraw.com