I don’t usually get involved in discussions about eating GMO foods, the rights and wrongs of pesticides vs organic farming or get into fights about the dangers of estrogen in soy products. But while working at the Kathy Smart expo recently a lady told me she couldn’t be vegan because she would have to eat tofu and she couldn’t do that because of – you know – all the problems with estrogen. I looked at her blankly, with no idea where she was going with her comments. “You know….estrogens in tofu. It’s supposed to be really dangerous? It gives you breast cancer?” I asked her for more information, but that’s all she knew. Someone, somewhere, had told her that soy products would give her cancer. Personally I would be more worried about arsenic in chicken, heavy metals in fish and salmonella in eggs if I were her, but hey, what do I know? Not very much apparently.
In all fairness, I knew less about the potential dangers of eating soy products than the lady who was using them as an excuse for not being vegan. So to redress the balance, I’ve now spent some hours investigating the matter, and I’ve come up with some interesting stuff. Please bear in mind that I used to be a medical research scientist, so I find it really annoying when people make sweeping statements without adding citations to back them up. Or quote statistics without quantifying the size of the study or qualifying what the control group was. A study of 5 people is very different to a study with 5,000 subjects, and a study group of 15 white male college students is going to give different results to one involving 100 people of different ethnic backgrounds, ages and gender. It seems that health and nutrition pseudo-science readily ignores the realities of actual science in order to sell more books. I’ve avoided putting links to Dr. Oz shows, popular magazines or anecdotal stories. Let’s try to find some actual facts!
So, is eating tofu as an adult (I’m not getting into the murky waters of breast feeding vs soymilk baby formula today!) likely to give you cancer?
These are some of my findings, based on recent research:
Consumption of soy foods is associated with a reduction in prostate cancer risk in men. This protection may be associated with the type and quantity of soy foods consumed.
Soy isoflavone intake could lower the risk of breast cancer for both pre- and post-menopausal women in Asian countries. However, for women in Western countries, pre- or post-menopausal, there is no evidence to suggest an association between intake of soy isoflavone and breast cancer.
Animal study shows why long-time consumption of soyfoods reduces breast cancer recurrence
The most recent studies support the idea that eating soy is a good thing as far as cancer is concerned. There are some low-key papers commenting on the benefits of eating fermented soy products rather than unfermented ones, but the actual data to support the claims is thin on the ground. However, it seems to make sense that eating tofu or tempeh is a better choice than munching on heavily processed faux-meat soy based products.
The flip side of the coin is that some studies indicate that eating soy may reduce the efficiency of thyroid medications. This abstract (written in 2006 – I can’t locate the full article) suggests that soy foods, by inhibiting absorption, may increase the dose of thyroid hormone required by hypothyroid patients. However, hypothyroid adults need not avoid soy foods. http://www.ncbi.nlm.nih.gov/pubmed/16571087. There doesn’t seem to be a lot of research on this issue, even though it featured in some chatty magazine articles from a few years ago.
Talking of chatty articles: If facts and figure’s aren’t your thing, check out this light-weight article written by some guy called Mark Hyman. I’m not endorsing him or his ideas in any way shape or form, I just thought this article was pretty good. http://drhyman.com/blog/2010/08/06/how-soy-can-kill-you-and-save-your-life/#close
Sorry if this blog reads as if it was produced by the soy marketing board, but I’m just reporting what I found. Of course, as an ex-scientist I know that anyone can find research to support whatever theory they wish to propose. The biggest forms of deceit are lies, damn lies, and statistics lol. I’d love to get feedback from you if you have an opposing view about soy with, of course, current research to back up your claims.
I know that once the Pandora’s box of eating tofu has been opened, topics such as “The dangers of GMOs” will pop out, but they can wait for another day….I don’t think my brain can handle any more scientific research papers today! I’m going to stop writing and cook myself some lunch. Yes, it’s got tofu in it 🙂
If you want to turn this soup into a meal, double the amount of tofu and ladle the soup over two bowls of freshly cooked noodles.
- 1 tbsp sesame oil
- 2 tomatoes, coarsely chopped
- 1 leek, thinly sliced
- 1 large king oyster mushroom, thinly sliced OR 8 fresh shiitake mushrooms, thinly sliced
- 5 cups dashi or stock (Make sure your dashi is vegan! Look for konbu instant dashi with no bonito)
- 1 cup (about 225g / 8oz) silken tofu, cut into small cubes
- 1 tbsp soy sauce
- 3 tbsp red miso
- 2 green onions, finely chopped
Preparation time: 5 minutes. Cooking time: 10 minutes. Serves 4.
Heat the oil in a medium pan and fry the tomatoes, leek and mushrooms for 3 minutes, or until softened. Add the dashi, tofu and soy sauce. Bring to a gentle simmer and cook for 5 minutes. Mix the miso with a small amount of the stock from the pan and add to the soup. Allow to simmer gently for 1 minute – do not let it come to a full boil. Divide the soup between four bowls and top with green onions. Stir gently before drinking because the miso will separate out while the soup is sitting in the bowl.
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