When we first released our menu in January 2021, questions arose around the topic of soy. Isn’t soy suspicious? Doesn’t soy contain estrogen?
Let’s address the soyful questions!
The short answer to the question of whether or not it is harmful to eat soy is no, scientific research has deemed that minimally processed soy is not only safe, but also nutritious to include in your diet. Unless you have a soy allergy or intolerance then, thankfully soy is not the enemy, it’s full of health promoting benefits.
We wanted to clear up misconceptions about soy products by sharing the latest research while addressing some common myths you may have heard about soy.
When discussing diet and nutrition – it can be a jungle out there! It’s hard to know where to look and what or who to believe. It is easy to become confused by all the different opinions. When researching nutrition, it’s important to check the credibility of the source, the background of the author and who has funded the referenced supporting studies.
Why do we include soy in our menu?
For the same reason we include oranges and broccoli and chickpeas! Our mission is to provide children in our care with healthful, colourful plant-based meals and snacks. Our menus are approved by a registered and practicing dietitian, Rebecca Phillips from Botanic Nutrition, to ensure that all the energy and macro/micronutrient targets are met for the preschool age group.
Traditionally soy foods have been used in many cultures as a reliable protein source for thousands of years. When eating a plant-based diet, minimally processed soy products, such as tofu, soy milk and edamame, pack a serious punch when it comes to nutritional ‘bang for your buck’. ‘Buck’ translating to ‘tummy space’ when working with little ones. Soy products are an excellent source of protein, iron, zinc, omega 3 fatty acids. They are low in saturated fat, cholesterol free, and are rich in fibre, potassium and magnesium. Soy can act as a wonderful alternative to meat and dairy products and a valuable addition to any diet with the extra benefit of health promoting and disease preventing effects (1).
Our menu includes a variety of whole foods, one of which is soy. We rotate foods to encourage eating a rainbow.
Isn’t the phytoestrogen in soy the same as estrogen? Doesn’t that mean it disrupts hormones?
Soybeans contain a natural plant compound called an isoflavone, which is classified as a ‘phytoestrogen’ (14). ‘Phyto’, Greek in origin, means ‘of a plant’, so although phytoestrogen and estrogen are similar in structure and name, these “plant estrogens” are not processed by the human metabolism in the same way as estrogen (2).
“In plants, phytoestrogens do not function as hormones, but as compounds. These defense compounds have fungistatic, antibacterial, antiviral, and antioxidant properties. They also prevent angiogenesis, thereby being important in the fight against malignant tumors.” (14)
Chickpeas, peas, beans, clover, lentils, alfalfa and other plants under the botanical “legume” umbrella, Fabaceae plant family, also contain isoflavones (14). Along with oats, flaxseed, barley, hops, yams, wheat germ, pomergranates, carrots, apples, coffee, licorice root, beer, bourbourn, clary sage, sesame seed, and jasmine oil as seen in the graphic below.
The most pervasive myth surrounding soy is that these isoflavones act as ‘hormone disrupters’ within the human body. If that is true, then we’d have to reject hummus, sprouts, falafel, pappadams, vegetables curries, coffee, beer, many Mexican, Asian and Indian dishes, and more.
Thus far, up to date research conclusions allow us to keep dipping into the hummus tub. As more research is conducted and shared, less negative associations remain around soy.
“There used to be concern around eating isoflavones due to its ‘estrogen-like’ activity in the body. However, isoflavones bind to estrogen receptors differently and function differently than estrogen.” (3)
A recent article in Critical Reviews of Science and Nutrition conducted a meta-analysis of 417 studies on human soy intake and hormone function. The evidence from human studies suggests that soy intake has no adverse effect on child health, child onset of puberty, estrogen levels, ovulation, sperm count or thyroid function. Not only do these results suggest soy foods cannot be classified as “hormone disruptors”, but they also found soy intake linked with a reduced lifetime risk of breast and prostate cancer. (4)
In the past women who were diagnosed with breast cancer or had a family history of breast cancer were told to avoid soy. However, current research suggests that women who consume soy have a 30% risk reduction in developing breast cancer (7). When soy is consumed in youth and early teen years its antioxidant properties have been found to prevent cancer in later years (7). Research has found other health benefits associated with soy intake, including a reduced risk of heart-disease (6), reduced risk of breast (7) and prostate cancers (8) and an alleviation of menopause symptoms (9). These proposed benefits are attributed to the isoflavones in soy, the phytoestrogens that investigations have thus far deemed helpful, not harmful in appropriate dosage (10).
How much is ‘too much’ soy?
1 serving of soy food contains approximately 7g of protein and 25mg of isoflavones. A safe amount to consume each day is around 3 – 4 serves. Examples of 1 serve: 120g tofu, 1 cup soymilk, 100g tempeh, 200g soy yoghurt and ½ cup of edamame (1). Our menu remains well below the safe amount of soy consumption, so your child would not reach an unhealthy level of soy intake while at school. We have so many other colourful, whole foods to enjoy that soy is only included as a part of our plant-based dishes.
In regards to overconsumption of soy,
“Data suggest that consuming soy protein in excess (greater than 100mg soy isoflavones per day) can lead to reduced ovarian function.” (16) 100mg of soy isoflavones would be equivalent to 16 cups (3.8 litres) of soy milk per day.
Consuming 100mg of soy isoflavones would be equivalent to 16 cups of soy milk (3.8 litres). The same study reports that “even up to 50 mg per day of soy isoflavones has little impact on serum circulating levels of hormones involved in reproduction.” (16)
It’s safe and healthy for you and your preschool age child to consume soy in moderation, our menu does just that, including soy in small amounts for its vitamin, antioxidant and protein content, well-balanced alongside many other beautiful whole foods.
What about soy allergies?
According to Australian Society of Clinical Immunology and Allergy (ASCIA), food allergies occur in 5-10% of children and 2-4% in adults in Australia and New Zealand. The most common allergies are dairy, egg, fish, shellfish, peanut, sesame, tree nut, soy and wheat. Around 2-3% of young children will test positive as having an allergy to soy, however less than 10% of that group will develop actual symptoms with soy exposure (11).
An ASCIA Action Plan is required for food allergies to ensure risk is avoided in the case of severe allergies. When a child with a soy allergy is enrolled, we will create an action plan to keep that preschooler safe and use alternatives to replace soy whenever it appears on the menu.
What about a non-allergy intolerance to soy?
Awareness of food intolerances is growing amongst Australians, as more people become conscious of their diet and the impact foods have on their individual digestive system. A person can develop food intolerance to anything they eat regularly. It is important to work with your healthcare practitioner to address any pattern of discomfort from eating certain foods.
We will work with families to avoid any food intolerances in the child’s diet while they eat at our preschool.
Isn’t soy farming bad for the environment?
Soy has been criticised for being responsible for mass deforestation and habitat loss, particularly the Amazon rainforest. Production of soy has doubled in the last decade. However, only 6% of global soy consumption is eaten directly by humans. Close to 80% is grown as animal feed to produce beef, chicken, dairy and eggs (12).
Considering the extreme cost of growing soy to satisfy global meat and dairy consumption, switching to a plant-based diet would significantly reduce international deforestation and habitat loss (13).
How do we use soy in our menu?
The soy milk we use in our menus is fortified with calcium, vitamin D, B2 and B12. Our menus are approved by a registered, practising dietitian to ensure daily nutrient targets are met for preschool age children. Naturally, there will be allergies, intolerances and preferences to consider and our in-house cook will take the time with each family to develop an individual meal plan specific to each child’s needs.
We are happy to work with families to accommodate soy allergies and intolerances. Please feel free to reach out to us with any questions or concerns about our menu.
- Messina, M. (2016). Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature. Nutrients, 8(12), 754. doi:10.3390/nu8120754
- Nutrition Facts.org Are plant-based protein are pea and soy protein harmful
- The Tracey Birnhak Nutritional Counseling Services (2019) Soy and Breast Cancer: Should breast cancer survivors eat soy foods?
- Messina M, Mejia SB, Cassidy A, et al. Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data. Crit Rev Food Sci Nutr. 2021;1-57. doi: 10.1080/10408398.2021.1895054
- Barnard, Neal, MD (2021) video: is soy dangerous?
- Setchell KD, Brown NM, Zhao X, et al. Soy isoflavone phase II metabolism differs between rodents and humans: implications for the effect on breast cancer risk. Am J Clin Nutr. 2011;94(5):1284-1294. doi:10.3945/ajcn.111.019638
- Wu AH, Yu MC, Tseng CC, Pike MC. Epidemiology of soy exposures and breast cancer risk. Br J Cancer. 2008 Jan 15;98(1):9-14. doi: 10.1038/sj.bjc.6604145. Epub 2008 Jan 8. PMID: 18182974; PMCID: PMC2359677./
- Yan L, Spitznagel EL. Soy consumption and prostate cancer risk in men: a revisit of a meta-analysis. Am J Clin Nutr. 2009 Apr;89(4):1155-63. doi: 10.3945/ajcn.2008.27029. Epub 2009 Feb 11. PMID: 19211820.
- Bolaños R, Del Castillo A, Francia J. Soy isoflavones versus placebo in the treatment of climacteric vasomotor symptoms: systematic review and meta-analysis. Menopause. 2010 May-Jun;17(3):660-6. PMID: 20464785.
- Setchell KD, Borriello SP, Hulme P, Kirk DN, Axelson M. Nonsteroidal estrogens of dietary origin: possible roles in hormone-dependent disease. Am J Clin Nutr. 1984 Sep;40(3):569-78. doi: 10.1093/ajcn/40.3.569. PMID: 6383008.
- Allergyfacts.org.au re: soy
- Soy and Sustainability – World Wildlife Foundation (WWF)
- Křížová, L., Dadáková, K., Kašparovská, J., & Kašparovský, T. (2021). Isoflavones. Retrieved 24 May 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6470817/#:~:text=Isoflavone%20Role%20in%20Plants,and%20antioxidant%20properties%20%5B26%5D.
- Setchell, K. D., & Clerici, C. (2010). Equol: history, chemistry, and formation. The Journal of nutrition, 140(7), 1355S–62S. https://doi.org/10.3945/jn.109.119776 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884333/
- Jefferson W. N. (2010). Adult ovarian function can be affected by high levels of soy. The Journal of nutrition, 140(12), 2322S–2325S. https://doi.org/10.3945/jn.110.123802 ncbi.nlm.nih.gov/pmc/articles/PMC3139237/