TO SOY OR NOT TO SOY?
We call foods that are lacking in one or more of the essential amino acids incomplete proteins or low biological value foods. These include grains, legumes, seeds, nuts, and vegetables. Protein combining theory combines incomplete protein foods in a meal to supply all the essential amino acids. In other words, you can create a complete protein by combining complementary incomplete protein foods.
In the 1970s, nutritionists believed that a meal must supply all the essential amino acids at the same meal and in the correct proportions to create a complete protein. This theory was promoted by Frances Moore Lappe in her book Diet For a Small Planet in 1971. However, in a newer edition published in 1982, she revised the protein combining theory and stated that a varied diet of grains, beans, and vegetables provides all essential amino acids even without intentional combining. The current protein combining theory follows her findings and states that we need not eat all of the essential amino acids at the same meal to make a complete protein. As long as we eat a variety of them throughout a day, the blood will store amino acids and create protein when needed. To make sure you are getting all the essential amino acids, it is helpful to know all the sources of the vegetable quality proteins.
Note that the protein combining theory is different than food combining theory where proteins are not eaten together with carbohydrates. According to the latter proteins and carbohydrates are digested differently and eating them together may result in incomplete protein digestion, especially with people with troubled digestive system.
Is Soy Good or Bad?
Soy protein contains all essential amino acids needed by humans and considered a complete protein equivalent to animal protein sources. It may be helpful in managing healthy cholesterol levels, and possibly decreasing the risk for bone loss and prostate cancer. There are many health claims about soy that still need more research.
What FDA allows is the following claim: “Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease”. In other words, foods must contain at least 6.25 grams of soy protein per serving and be low in fat, cholesterol, and sodium.
There are a few concerns about soy protein:
Trypsin is a protein digesting enzyme present in the small intestine. Soy contains Bowman-Birk inhibitor that inhibits trypsin in the body decreasing the usable value of protein and amino-acids in soy. To avoid that, it is recommended to consume soy previously fermented. More traditional diets have a greater advantage to our health as they use fermented soy in the form of miso, shoyu, tamari, and tempeh.
On the other hand, Bowman-Birk inhibitor has anti-inflammatory properties, which may be helpful in decreasing chronic illnesses and cancer.
Phytoestrogenic Isoflavones / Goitrogens
Soybeans are the most concentrated source of isoflavones in the human diet. Isoflavones are phytoestrogens, which means they are plant-based substances that have estrogen-like effects in the body. Their health benefits and health risks remain controversial and require more research and study. There are two main phytoestrogens: genistin and daidzin present in soy foods. A scientific hypothesis assumes that soy isoflavones may inhibit an enzyme essential to thyroid hormone synthesis. This effect seems to be worse in those with low iodine levels. According to the American Thyroid Association, 20 million Americans have some form of thyroid disease, of which 60% are unaware of their condition. Female are more susceptible than male. If you are aware about your low thyroid function, you should be cautious about eating soy products, especially unfermented like tofu and soymilk.
In the intestine, phytoestrogens must be activated by the intestinal bacteria or by fermentation. Fermented soy is a lot more absorbable, which more likely accounts for soy’s beneficial effect on bone density and decreased risk for hormone sensitive cancers of the prostate. Epidemiological studies have shown women who have a lifelong history of eating soy as part of their diet have a decreased risk for breast cancer. However, it is still unclear if consuming these plant compounds is safe for breast cancer survivors.
Soy Baby Formula
Another concern about phytoestrogens is their presence in soy baby formulas. Infants fed this type of formula end up with much higher levels of phytoestrogens than adults eating soy products. Research has demonstrated very controversial results, in favor and against consuming the soy based formula. However, there are still many concerns about the possible adverse effect on the endocrine and sexual development of children raised exclusively on soy formulas. More studies need to be done in a controlled way and to see the long-term effects.
Phytates are compounds found in grains and soy that can reduce the bioavailability of minerals like calcium and iron. To reduce the phytates content in the food, we soak the grains overnight and we ferment the soy into miso, shoyu and tempeh. Boiling can reduce phytate levels as well. In addition, we have bifidobacteria in our gut capable of breaking down the phytate. The overall effect of phytate in soy on its bioavailability can be significantly minimized.
The issue about soy that cannot be omitted is the latest biggest health concern about soy products in the US coming from genetically modified soybeans specifically designed to be resistant to the weed-killer glyphosate or Roundup.
The concern about the unpredictable devastating effects of this chemical on the human health leads to taking steps of precaution as making sure to buy organic and/or non-GMO foods, including packaged and processed foods, fresh fruits and vegetables, and dried foods. Soy has made into so many foods today you can’t possibly think of. Making sure that an item is labeled non-GMO is always smart shopping.
Elegant Miso Soup
1 carrot, cut in thin rounds
1 inch piece of wakame
½ cup daikon, cut in thin rounds
A handful of arugula
1 flat tsp miso per cup of soup
1 tbsp juice from fresh lemon
Rinse off piece of wakame and place in a small dish of water to soak until tender.
Finely slice the wakame and place in a saucepan with fresh spring water.
Bring to a boil uncovered over a medium flame.
When broth is boiling, add finely sliced vegetables, all except leafy greens.
Simmer all until tender, about 3-5 minutes.
Dilute miso paste in a small amount of water from the soup, puree until smooth.
Pour diluted, pureed miso into simmering broth.
Add finely sliced leafy greens at this point.
Simmer, do not boil, miso in soup for 3-4 minutes.
Add lemon juice.
1 package of tempeh
½ inch piece of dried kombu, soaked for 10 minutes
1 cup water
½ tsp tamari
1 medium onion, sliced
1 tbsp olive oil
1/3 cup grapeseed vegenaise
2 tsp red onions, diced
1 dill pickle, diced
2 tsp stone ground mustard
¼ tsp sea salt
¼ cup parsley
¼ cup toasted pecans, chopped
To a small saucepan, add water, kombu, and tempeh. Cover, bring to a boil, then lower the flame, and steam for 15 minutes. Remove tempeh into a plate and let cool down. Crumble or mash in a bowl.
Saute sliced onion in a skillet with olive oil until browned.
Place all of the ingredients into a cuisinart and process. Let the mixture remain grainy and not completely pureed. Serve with your favorite crackers.