Soy comes from soybeans, which are legumes. Recall from week 7's "G" word "garbanzo beans" that legumes grow in pods containing seeds (or “beans” as we call them). Like garbanzo beans, soy beans are an incredible source of both protein and carbohydrates.
Unlike some plant proteins, soy protein is considered a complete protein, containing all nine essential amino acids that the body cannot make which must be obtained from the diet. This means they are not only a primary source of protein for our vegan friends, but are also a great element to add to any plate- regardless of your dietary restrictions (plant based, carnivorous, etc.).
You've most likely consumed and/or heard of soy in milk or meat-alternatives, specifically tofu...though soy parades around in one-too-many forms - from soy cheese to soy ice cream to soy bacon.
FUN FACT: Soybeans vs. Tofu
Tofu has a higher ratio of protein and a lower ratio of carbohydrates compared to soy beans because tofu is made from condensed soy milk. This is because in the condensation process (when water vapor turns to liquid water), many of the carbs are removed!
Condensation is the same process responsible for ground-level fog, for your glasses fogging up when you go from a cold room to the outdoors on a hot, humid day, for the water that drips off the outside of your glass of iced tea, and the water on the inside of your windows on a cold day.
MENACE OR MIRACLE WORKER?
Soy products are in the hot seat more than the amount of Kanye / Kim / Pete drama in your newsfeed. Soy is praised as a cure for hot flashes, warding off osteoporosis, and protecting against hormonal cancers like breast and prostate by some...And completely shunned by others who state that it may cause breast cancer, thyroid problems, and dementia. Studies have shown that preparation methods are key to whether or not soy affects the body positively or negatively.
POTENTIAL POSITIVES 🙋
- Vitamin K: In preparation methods like Natto (photo below), soy can provide vitamin K2 - which influences appetite; for example, a study in European Journal of Clinical Nutrition found that participants receiving K2 showed greater amounts of weight loss and less abdominal fat overall.
- Phospholipids: great source of phospholipids; recall from Blood Brain Barrier (B) and Omega 3’s (O) that phospholipids give our brain cells shape & strength! Phospholipids also help out with memory recall, like improving short term memory too.
- Prevent memory decline: Soy contains lots of isoflavones. Isoflavones are types of estrogen-based guys found in plants (bougie name: "phytoestrogen"). Yes, they do indeed function similarly to the human hormone estrogen (source). Some propose these isoflavones, due to their ability to mimic estrogen hormone, can limit age-related memory loss or decline in thinking skills.
POTENTIAL NEGATIVES 🙅
- Leaky Gut: Soybean "agglutinins" have been found as sidekick-culprits in cases of leaking guts - which means your small intestine has holes in it! This prevents the gut from sucking up all the 'good' nutrients from your food!
FERMENTED OR UNFERMENTED?
Soy foods are also classified as fermented or unfermented. Fermented means that the soy food has been cultured with beneficial bacteria, yeast, or mold. Some believe that fermenting soy improves its digestibility and absorption in the body, as this process partially breaks down soy’s sugar and protein molecules.
Examples of FERMENTED soy is tempeh and soy sauce, while examples of UNFERMENTED soy are soy milk and tofu (source)
WHAT DO WE KNOW FOR SURE?
As stated earlier, soy products are constantly in the hot seat! So...here's what we know for sure about SOY PRODUCTS
1.) SOY & BLOOD PRESSURE: Soybean protein supplementation resulted in a reduction in systolic and diastolic blood pressure. These findings suggest that increased intake of soybean protein may play an important role in preventing and treating hypertension (source). Soy is a polyunsaturated fat, meaning - like Omega-3's - it can lower levels of total cholesterol and LDL (“bad”) cholesterol to a small extent (recall week 12's word LDL: low density lipoproteins, the villainous, artery clogging form of cholesterol).
2.) SOY & THYROID: Your thyroid is a gland in control of many things - including metabolism and nervous system function. The thyroid gland is fueled by iodine - yes, the same kind found in salt! Soy may alter thyroid function in people who are deficient in iodine. Your thyroid can be 'normally' functioning, 'overactive' called hyperthroidism (metabolism speeds up and iodine levels are high), or 'under active' called hypothyroidisim (metabolism slow down and iodine levels are low). SO, those with an 'under active' thyroid called hypothyroidisim might be affected by soy isoflavone intake.