Growing up, I lived off of steak, chicken, turkey, and practically anything that is meat. It wasn’t until high school that my entire diet changed, going from almost everything to a vegetarian lifestyle. Being vegetarian was not difficult because I was able to get my sources of protein from numerous other foods such as yogurt, milk, cheese…etc. However, it wasn’t until recently that I decided to make the switch to veganism, which cut out a tremendous amount of those options except tofu. I have built such a strong reliance on tofu as my main source of protein, but have began to wonder whether or not tofu is actually my best, healthiest option.
First off, when I say healthy, I mean loaded with nutrients, not processed, and not damaging to ones overall well being. Tofu is loaded with protein, in fact one serving offers 9 grams (Times)!… Without a doubt, protein is definitely a must in a healthy, well-balanced diet to ensure a fulfilling and energetic lifestyle. If you don’t believe me, click here and find out more about how much protein your body needs to be healthy! Though I run into problems when I examine where that protein is actually coming from… The main ingredient in tofu is soy, which comes from soybeans (a legume). In a recent interview on the Dr. Oz show, with Christina Patrick, an interested dietician and member of Dr. Oz’s Medical Advisory Board, the soy controversy is laid out. Soy acts as the main resource in which we retrieve our protein when consuming tofu. However, soy contains phytoestrogen, which has isoflavones, (estrogen of a plant) which brings us to the most controversial issue of all: Breast Cancer. Now, some may question Dr. Oz’s findings as he may not deem to be the most reputable source, but there are many studies and articles that closely align to the isoflavones found in soy and how it correlates to cancer development. Specifically, in this article published in the Scientific American, the findings are identical in that with increased consumption of these products containing isoflavones, (like tofu) it may lead to, “…reduce[d] fertility in women, trigger premature puberty and disrupt development of fetuses and children” (Frinka 1). The study then concludes by noting “large amounts”, and that consumption in moderation is okay. This makes me wonder how much “too much” is…
So what are in isoflavones that cause such a damage? In tofu, specifically in soy, there is a type of estrogen called genistein found in isoflavones. In a recent study published in the Scientific American, animals were given doses of genistein, seeing how it affected their bodies. Genistein- right off the bat- has proven to stop reproduction of organisms. Anyways, back to the experiment, female animals were given 25 grams which is the amount of soy that is in a typical high- soy diet. The effects produced delayed reproductive cycles, and even absence of reproduction. When testing males, there were no significant changes except breast growth. After analyzing these results, I have come to my own consensus on the study and tofu as a whole. 1- Because of the fact that tofu contains genistein, I suggest consuming it in moderation. 2- Just because tofu has genistein does not mean that correlation will prove causation; just because you consume tofu does not mean you will develop cancer or increase in breast growth, however risk of such may increase. 3- There could have been a difference in results if the study took place over a longer period of time. The female study was over the course of 4 days, there may still be long term effects that were not proven in this experiment.
Going back to the interview, Christina describes another experiment, in which every women examined had drank 1 cup of soy milk everyday, or 1 serving of tofu, and their risks of developing breast cancer fell by 30%. However, the experiment lacks a control group! The control group of having one group not drink or eat any soy products is a must in order to be able to compare the results and draw conclusions! This is a soft-endpoint that needs further examination, because risk of development is a very hard thing to measure, due to things like chance.
So, now that you know the uncertainty, but positives working in tofu’s favor, now what? Well, it is really important to point out that correlation does not equal causation, meaning just because you eat tofu you will / will not develop cancer, or just because you do not consume tofu, your guaranteed a breast-cancer free life. There are many third variables that could interfere, such as the amount of tofu consumed, the way in which it is cooked (steamed, fried, boiled, etc…), and more variables that could affect the later possibility of developing cancer. The evidence is not conclusive, there could be long term affects that we are unaware of. Also, the claim made about the Asian population is solely observational, so it is impossible to prove if whether or not there lies full certainty in that statement. That being said, I think tofu is a great source of protein and like any other food, when consumed in moderation, it serves as a healthy option and great source of protein.