I’m “soy” confused

FEELING CONFUSED ABOUT EATING SOY? READ ON TO BE INFORMED

There is definitely a lot of confusion around eating “soy” because of its phytoestrogenic properties. But what if I told you the primary dietary source of phytoestrogens in the U.S. diet is actually from lignan’s found in legumes, whole grains, seeds, fruits, vegetables, tea and coffee. Would you stop eating those foods as well. Probably not, because you would have little left to eat. So lets really get into the science behind soy and where people have gotten confused along the way.

Soybeans are composed of phytic acid, alpha linolenic acid (ALA), lignan’s and isoflavones. So which one of these components raises controversy. It’s the isoflavones in soy, which are the primary phytoestrogens, also known as genistein and daidzein. These compounds contribute to soys health benefits, but also possible uncertainty.

How many soy products are you aware off and whats the difference? To be an informed consumer lets take a look at the spectrum of soy products.

Whole Soy Products:

Edamame: These are whole, immature green soybeans. You may recognize them as an appetizer in Japanese restaurants.
Soy nuts: These are whole soybeans that have been soaked in water, then either baked or roasted, to get crisp and brown. Taste a little bit like peanuts, but have more protein and less fat.
Tempeh: This product is made by softening soybeans and then adding a fermentation starter. It is often found in block form and and has a nutty flavor.

Minimally Processed Soy Products:

Soy milk: This plant-based milk is made from soybeans and filtered water. Just as a reminder, when choosing non-dairy milks, always read the labels. Best products are the ones that contain the main ingredient and water. Avoid sugars and carrageenan (a food additive used to preserve and thicken foods, including nut milks, meat products, and yogurt).
Miso: This a fermented paste made from soybeans with koji (Aspergillus oryzae - cultivated from rice, barley, or soybeans). I am sure you have had a bowl of Miso soup, so now you have already had soy.
Tofu: This is probably the most familiar for you. It is made from condensed soy milk and formed into a block, similar to cheesemaking.

Moderately Process Soy Products:

Soy yogurt: Just like any other yogurt, soy yogurt is made by using a milk (soy in this case) and adding yogurt bacteria, and possibly sweeteners.
Soy cheese: Similar to how other cheese are made, but something to note is, soy cheese may contain casein which is an animal based product, read your labels, and if you are vegan, this may come into consideration.
Soy isolate protein powders: This product is ultra processed from soybean flakes that are washed in acid/water (acid washing) to remove sugars and fiber.

ARTICLE CONTINUES BELOW

Numerous studies have been performed to assess the safety of soy consumption. They found that normal consumption of food-based phytoestrogens, like those found in soy, did not elicit a harmful physiologic response in humans. Controversy arose due to results from clinical trials using dietary soy, soy protein isolate and isoflavone supplementation.

I don’t know if you recall, quite a few years back, there was an article run in the NY times and then all over FB, that caused quite a bit of stress, and numerous phone calls my way. Well, if you actually look at the science behind that study, they used soy protein isolate in excessive amounts that would not normally be eaten. Personally, I do not consider soy protein isolate a real food. It is ultra-processed and just like other processed foods can contain contaminants that we do not want in our bodies. Some of those may include phytates, hexane and aluminum. They can build up in our systems and also prevent proper nutrients from being absorbed.

WHERE SCIENCE MEETS WELL-BEING

Let us take a look at what the research really tells us:

The Shanghai Breast Cancer Survival Study looked at this question in a population-based cohort study of 5042 female breast cancer survivors in China who were followed for an average of 3.9 years. Among women with breast cancer, soy food consumption was significantly associated with decreased risk of death and recurrence.
Another cohort of 1,954 female breast cancer survivors who were prospectively followed for 6.31 years found that soy isoflavones consumed at levels comparable to those in Asian populations may reduce the risk of cancer recurrence in women receiving tamoxifen therapy and appeared not to interfere with tamoxifen efficacy.
In women who did not have a previous history of cancer, a 2011 meta-analysis of prospective studies concluded that "soy isoflavones intake is associated with a significantly reduced risk of breast cancer incidence in Asian populations, but not in Western populations"
A large meta-analysis looking at studies from 2000-2013 found a statistically significant inverse association between soy intake and breast cancer, although this inverse association was stronger for Asian women than Western women.
Soy isoflavones from soy protein, i.e. genistein and daidzein, inhibit prostate cancer growth in vivo and in vitro by blocking hormone receptor activity to inhibits cell proliferation.
Soy may lower rates of heart disease by improving heart protective factors.
Soy isoflavones may reduce the frequency of hot flashes in post menopausal women.
Individuals who eat soy, reduce their risk of breast cancer by 30% overall. Women who eat soy products once a week have 48-56% lower risk.

These are just a few of the studies, there are plenty more, but I have put the references below if you really want to get into the science.

So let me break it down for you. I do eat soy. I am not afraid to eat soy, but I am careful about what soy I eat. I do not put soy proteins isolates in my shakes. I eat non-GMO soy, even though current scientific evidence does not show that non-GMO foods are healthier than GMO foods. As we do not know the long term affects, I will just stick with avoiding artificial foods which we know have the capacity to cause inflammation, so I choose organic non-GMO soy products. I eat tofu 2-3 times a week, edamame often, and tempeh occasionally. These are some my main sources of protein. Also as someone who has diagnosed over 100,000 breast cancers, I feel the research actually shows us that eating real soy foods is protective for a number of health conditions.

MAKE A DIFFERENCE BY SHARING THIS ARTICLE WITH OTHERS TO ENCOURAGE WELLBEING ⤵

REFERENCES:

Peterson J, Dwyer J, Adlercreutz H, Scalbert A, Jacques P, McCullough ML. Dietary lignans: physiology and potential for cardiovascular disease risk reduction. Nutrition reviews 68(10):571-603 Oct, 2010.
Kyrø C, Zamora-Ros R, Scalbert A, et al. Pre-diagnostic polyphenol intake and breast cancer survival: the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Breast Cancer Res Treat. 2015;154(2):389-401.
Chen MN, Lin CC, Liu CF. Efficacy of phytoestrogens for menopausal symptoms: a meta-analysis and systematic review. Climacteric 18(2):260-9 Apr, 2015
Messina M, McCaskill-Stevens W, Lampe JW. Addressing the soy and breast cancer relationship: review, commentary, and workshop proceedings. Journal of the National Cancer Institute 98(18):1275-84 Sep, 2006.
Shu XO, Zheng Y, Cai H, Gu K, Chen Z, Zheng W, Lu W. Soy food intake and breast cancer survival. JAMA : the journal of the American Medical Association 302(22):2437-43 Dec, 2009.
Dong JY, Qin LQ. Soy isoflavones consumption and risk of breast cancer incidence or recurrence: a meta-analysis of prospective studies. Breast cancer research and treatment 125(2):315-23 Jan, 2011.
Mourouti N, Panagiotakos DB. Soy food consumption and breast cancer. Maturitas 76(2):118-22 Oct, 2013.
Pavese JM, Krishna SN, Bergan RC. Genistein inhibits human prostate cancer cell detachment, invasion, and metastasis. Am. J. Clin. Nutr. 100 Suppl 1:431S-6S Jul, 2014.
Mitchell JH, Cawood E, Kinniburgh D, Provan A, Collins AR, Irvine DS. Effect of a phytoestrogen food supplement on reproductive health in normal males. Clinical science (London, England : 1979) 100(6):613-8 Jun, 2001.
Bouchenak M, Lamri-Senhadji M. Nutritional quality of legumes, and their role in cardiometabolic risk prevention: a review. J Med Food. 2013;16(3):185-198.
Goodman-Gruen D, Kritz-Silverstein D. Usual dietary isoflavone intake is associated with cardiovascular disease risk factors in postmenopausal women. J Nutr. 2001;131(4):1202-1206.
Zhang C, Ho SC, Lin F, Cheng S, Fu J, Chen Y. Soy product and isoflavone intake and breast cancer risk defined by hormone receptor status. Cancer Sci. 2010;101(2):501-507.
Douglas CC, Johnson SA, Arjmandi BH. Soy and its isoflavones: the truth behind the science in breast cancer. Anticancer Agents Med Chem. 2013;13(8):1178-1187.

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