I bet you’ve heard that you should stop eating soy because it’s bad for you. It’ll cause breast cancer and your male partner will start to grow breasts. This article will break this major misconception and encourages you to eat soy, because it’s good for you! 

The soybean has been considered one of the five sacred grains of China dating back to 2900 BC. The bean is widely known for its high protein (40%) and oil (20%) content. However, one of the reasons (a good one) that it gets a bad reputation is because it’s the second largest genetically engineered (GE) export crop in the United States, specifically for soybean oil. The soybean was one of first GE crops, and as of 2012, 97% of soybeans grown in the U.S. are GE crops. This means it uses up a lot of pesticides (ie. glyphosate) and is added to many processed foods because of it’s affordability and availability. However, benefits from soy doesn’t come from extracted genetically modified soybean oil. In the U.S., the leftover part of the bean is used to make animal feed and a small percentage is used for food products such as tofu, tempeh, textured vegetable protein, miso, soy sauce, and soy lecithin. These products are what give you health benefits, and buying organic eliminates the concern of pesticide residue.  

WHAT THE RESEARCH SAYS ABOUT CONSUMING SOY

There has been much debate over the past decade about the constituents of soy and if they’re harmful. Specifically, soy isoflavones, which are known phytoestrogens (phyto means plant). When absorbed, phytoestrogens act like very weak estrogens in the body. The most researched isoflavones are called Diadein and Genistein. These are the molecules that have caused great controversy in the efficacy of the safety of soy products. Many experts consider them useful in the prevention of cancer, while others see them as endocrine disruptors and carcinogenic.

However, when reviewing the most current research, we find consistently that consuming soy products is GOOD for you!

HERE ARE THE RESULTS:

• A review study from 2019 found that soy isoflavones are protective against cognitive decline and Alzheimer’s disease. The protective mechanisms were likely due to the soy isoflavones having antioxidant and anti-oxidative stress properties.
• A recent study by the Academy of Nutrition and Dietetics examined effects of soy isoflavones and soy protein on breast cancer. They found that intake of both soy isoflavones and soy protein were significantly associated with lower mortality rates from breast cancer. A 10mg/day increase in soy isoflavone intake was associated with a 9% lower risk of death from breast cancer.
• A 2018 study focused on the relationship between soy isoflavones and cardiovascular disease in early menopausal women. Participants were given either soy protein with or without isoflavones and were monitored for 6 months. After 6 months, results revealed women consuming soy protein with isoflavones had a significant reduction in blood pressure, a 27% reduction in heart disease risk, a 37% reduction in heart attack risk, and a 42% reduction in cardiovascular disease risk.
• A recent study from 2020 examined the relationship between soy intake and serum lipids in postmenopausal women. Results indicated that both isolated soy protein and soy isoflavone intake significantly reduced triglycerides, total cholesterol, and LDL cholesterol.

OTHER NUTRITIONAL BENEFITS SOY OFFERS

Soy offers essential vitamins and minerals, complete protein, and high antioxidant properties.

• Vitamins: Soy has a higher concentration of calcium, folate, and choline in comparison to other common grains such as corn, wheat, and rice.
• Calcium is essential for bone growth and repair. The National Institutes of Health list soy products as a source for calcium intake. This is an important note for those who are dairy-free. Soy supplements are not recommended as a source for calcium, as there is not enough evidence to show this is beneficial.
• Folate is a B vitamin essential for DNA replication and repair. Soy offers approximately 165mcg in 2/3 cup serving. The CDC recommends 400mcg of folate daily, especially among young women whom could become pregnant.
• Choline is an essential B-complex vitamin and is the precursor needed for the important neurotransmitter acetylcholine. Choline is found in the highest amounts in eggs and fatty meats. For those on a vegetarian diet or avoiding eggs and red meat, soy is a great alternate source for choline as 2/3 cup contains 116 mg.
• Alpha-linolenic acid: ALA is an omega-3 essential fatty acid, which means it is necessary to consume ALA through the diet. ALA is an important molecule found in the cell membrane and used to make EPA and DHA, which are important for brain and nerve health and help the body make anti-inflammatory factors. Soybeans contain 8% ALA of the oil content.

HOW TO SAFELY ADD SOY TO YOUR DIET

• Choose whole soy foods when possible. Tofu, tempeh, edamame, and miso are examples. Studies show that it is more beneficial to consume the whole soybean than processed soy such as soybean oil or textured vegetable protein.
• Choose organic soy products. Any soy products that are not labeled organic are likely to be made from genetically modified soybeans.
• Choose fermented whole soy. Research has shown increased benefits from fermented soy beans verses non-fermented. The fermentation process breaks down some of the phytates in soy making it easier to digest. It also adds in beneficial probiotics. Examples are tempeh, miso, natto, soy sauce, or tamari.
• Up to three servings a day is a conservative safe limit for soy products even if you have a family history of breast or prostate cancer.
• And of course, if you know you have a sensitivity or allergic reaction to soy, don’t consume it.

Check out this article by Fullscript for more reading on the benefits of soy: Is Soy Bad for You? Examining the Connection Between Soy and Hormones.

References:

“2012 ARMS – Soybean Industry Highlights.” NASS – Surveys – Agricultural Resource Management Survey. United States Department of Agriculture, n.d. Web. 22 Feb. 2014.

“Choline.” Micronutrient Information Center. Linus Pauling Institute at Oregon State University, n.d. Web. 24 Feb. 2014.

Cui, C., Birru, R., Snitz, B., Ihara, M., Lopresti, B., Aizenstein, H., Lopez, O., Mathis, C., Miyamoto, Y., Kuller, L. and Sekikawa, A., 2006. Effects of soy isoflavones on cognitive function: a systematic review and meta-analysis of randomized controlled trials. Alzheimer's & Dementia, 14(25), pp.1365-1366.

Evert, Alison. “Calcium in the Diet.” MedlinePlus. National Institute of Health, 18 Feb. 2013. Web. 22 Feb. 2014.

“Facts about Folic Acid.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 13 Jan. 2012. Web. 24 Feb. 2014.

“Full Report (All Nutrients): 16108, Soybeans, Mature Seeds, Raw.” Agricultural Research Service United States Department of Agriculture. National Nutrient Database for Standard Reference, n.d. Web. 22 Feb. 2014.

Moradi, M., Daneshzad, E. and Azadbakht, L., 2020. The effects of isolated soy protein, isolated soy isoflavones and soy protein containing isoflavones on serum lipids in postmenopausal women: A systematic review and meta-analysis. Critical Reviews in Food Science and Nutrition, 60(20), pp.3414-3428.

Nachvak, S., Moradi, S., Anjom-shoae, J., Rahmani, J., Nasiri, M., Maleki, V. and Sadeghi, O., 2019. Soy, Soy Isoflavones, and Protein Intake in Relation to Mortality from All Causes, Cancers, and Cardiovascular Diseases: A Systematic Review and Dose–Response Meta-Analysis of Prospective Cohort Studies. Journal of the Academy of Nutrition and Dietetics, 119(9), pp.1483-1500.e17.

Pedersen, Palle. “Soy Isoflavones.” Soybean Extension and Research Program. Iowa State University, 17 July 2007. Web. 24 Feb. 2014.

Sathyapalan, T., Aye, M., Rigby, A., Thatcher, N., Dargham, S., Kilpatrick, E. and Atkin, S., 2018. Soy isoflavones improve cardiovascular disease risk markers in women during the early menopause. Nutrition, Metabolism and Cardiovascular Diseases, 28(7), pp.691-697.

Shurtleff, William, and Akiko Aoyagi. “SoyInfo Center.” The Soybean Plant: Botany, Nomenclature, Taxonomy, Domestication, and Dissemination. Soyinfo Center, Lafayette, California, 2007. Web. 24 Feb. 2014.

“Soybeans.” Soybeans. The George Mateljan Foundation, n.d. Web. 22 Feb. 2014. <http://www.whfoods.com/genpage.php?tname=foodspice&dbid=79>.