It can be a big part of a vegetarian diet. Most of the nutrients that vegetarians have to be aware of, such as iron, protein, vitamin B12, and omega 3 fatty acids, are contained in soy and soy products (Eating). For many meat dishes, tofu is a great substitute. Soymilk is a delicious alternative to dairy milk. Soy and soy byproduct are also “used as an additive in various processed foods, including baked goods, cheese, and pasta” (Soy). Soy is found in many places, but could this be a problem?
In the blogosphere, there’s some harsh debate.
Zenhabits, named one of the top 25 blogs on the internet in 2010 by Time Magazine and with over 260,000 subscribers, is a blog about minimalism with the occasional post on vegetarianism and veganism. The author, Leo Babauta, describes himself:
I have no formal qualifications. I am not an expert, or a doctor, or a coach. I haven’t made millions of dollars and I’m not the world’s greatest athlete. All I am is a regular guy, a father of six kids, a husband, a writer from Guam (now living in San Francisco). But I have accomplished a lot over the last couple of years (and failed a lot) and along the way, I have learned a lot.
This discredits him as an expert in nutrition, but his blog post on soy represents the one side of the debate on soy’s effects. People who drink and eat soy products will often get this type of response: “I mention (to otherwise smart and informed people) that I drink soymilk sometimes, and a look of pity comes over their faces. ‘This guy doesn’t know the dangers of soy, and might get cancer, or worse … man boobs,’ they’re thinking” (Finally). This type of talk develops from news stories that link soy to breast cancer and from the fact that soy contains phytoestrogens. With the word estrogen, people automatically think female. It is true that men can grow boobs with increased levels of the hormone estrogen, but not soy’s phytoestrogens. Babauta defends soy by stating,
Soy has been eaten in moderation for centuries, and as I said above, has not been shown to be unhealthy. It can be included in a healthy diet — tofu, some soy milk, whole soy beans, tempeh can all be good for you if you mix them in with the other real foods I mentioned above. I would be cautious about overly processed soy foods — processed soy protein — just as I would any other processed foods. Meaning, don’t be afraid of them, but don’t make them a major part of your diet. Eat real foods instead. And organic is healthier.
Basically, eating natural and unprocessed foods is always better, but the occasional processed soy food is nothing to be worried about. He does cite some sources for his reasoning, but for many people, that’s not good enough. He received much backlash, partly because of his lack in expertise.
Melissa McEwen runs a blog called HuntGatherLove. She states that she was “studying agriculture at the time I started this blog and I intensified my study in ecology, nutrition, and anthropology. I finished my Bachelor’s of Science in 2009 and have since done some grad work in evolutionary biology and anthropology.” She seems to have more authority on nutrition and represents another side on the debate about soy. Her blog post directly confronts Babauta’s post, citing many more peer-reviewed scholarly sources and analyzing Babauta’s sources. Her stance on soy:
I eat soy sauce and I confess I sometimes indulge in Korean tofu stew (simmered in stock), I just don’t use soy as a staple food because I’ve seen the science and the science says “caution.” And more caution about getting dietary advice from a blog about “zen habits.” A hint for future writers from that blog: You can’t find studies about why soy might be bad by searching “soy bad.” You have to know something about biology and what to look for.
Minus the remark about Babauta’s blog, her statement seems to be a summary of what the other side thinks about soy; right now research is pointing toward some negatives for soy consumption.
The official fact sheet from the National Center for Complementary and Alternative Medicine (NCCAM) under the National Institutes of Health (NIH), states that:
- Soy is considered safe for most people when used as a food or when taken for short periods as a dietary supplement.
- Minor stomach and bowel problems such as nausea, bloating, and constipation are possible.
- Allergic reactions such as breathing problems and rash can occur in rare cases.
- The safety of long-term use of soy isoflavones has not been established. Evidence is mixed on whether using isoflavone supplements over time can increase the risk of endometrial hyperplasia (a thickening of the lining of the uterus that can lead to cancer). Studies show no effect of dietary soy on risk for endometrial hyperplasia.
- Soy’s possible role in breast cancer risk is uncertain. Until more is known about soy’s effect on estrogen levels, women who have or who are at increased risk of developing breast cancer or other hormone-sensitive conditions (such as ovarian or uterine cancer) should be particularly careful about using soy and should discuss it with their health care providers.
From this statement it is clear that women should be careful about their intake of soy, otherwise, nothing is certain about the effects of soy.
From all this I can deduce that too much of one food is never a good thing. Mix meals up and avoid too many processed foods in general. We just need to remember to stop worrying so much and focus on more of the good things in life.
Eating Guidelines for Vegans. Dietitians of Canada. http://www.dietitians.ca/Nutrition-Resources-A-Z/Factsheets/Vegetarian/Eating-Guidelines-for-Vegans.aspx. Sep 1, 2010. Accessed July 5, 2013.
Soy. Nation Center for Complementary and Alternative Medicine. http://nccam.nih.gov/health/soy/ataglance.htm. April 2012. Accessed July 5, 2013.
Babauta L. Finally, the Truth About Soy. Zenhabits. http://zenhabits.net/soy/. May 30, 2011. Accessed July 5, 2013.
McEwen M. Zen Habits: stupid about soy. Huntgatherlove. http://huntgatherlove.com/content/zen-habits-stupid-about-soy. May 30, 2011. Accessed July 5, 2013.