Soy, and mainly soy food products such as soy milk, tofu, miso, etc., is probably one of the absolute worst foods (ahem I should say processed foods) you can eat; however edamame- which is the actual untouched soy legume is perfectly fine because it is in its raw state like any bean and legume. When it is processed it's chemical biproducts from the soy isoflavones become extremely estrogenic to the human body and it actually is viewed to be a toxic poison by our systems.
People then will say: "Ok, but what about the Japanese who eat it all the time." Well that's not entirely true. They also eat twice as much, if not more in healthy fats from wild caught seafood. Americans are told to do the opposite and eat "low fat" which then directly interferes with good health. Additionally mainland Japanese are not too far from being in sync with the U.S. health issue epidemics of diabetes, cancer, high cholesterol, high blood pressure, etc. The coastal Japanese are the ones who eat far, far less soy products and far more of wild caught fish (which keep in mind has about 85% more omega 3 than its farm-raised counterparts) and other healthier foods. Researchers at Wake Forest University School of Medicine conducted a few studies and have found that farm-raised tilapia and catfish contain less than one-eighth the amount of omega-3's that are found in farm-raised salmon or trout. Additionally, and this is where a real health concern can come in, is that the tilapia and catfish also had much larger amounts of omega-6 acids than the salmon or trout which throws off the natural ratio. When Omega 6 is consumed in greater amounts it can have negative health potential.
Dr. Gabe Mirkin states that: "A crucial part of a healthful diet is the ratio of omega-6s to omega-3s. Your immunity is supposed to be good for you by killing gems before they can harm you. However, if your immunity stays active, it starts to attack your own body to increase risk for heart attacks, certain cancers and even asthma and some types of arthritis. Omega-3 fatty acids produce prostaglandins that turn down your immunity to help prevent inflammation and the health problems it can cause. Omega-6 fatty acids promote inflammation. A major explanation for the high heart attack rate in North Americans is the high ratio of omega-6s to omega-3s in the diet that contains lots of omega-6s from vegetable oils and low amounts of omega-3's found in fish and seeds."
Let's get back to mainland versus coastal Japanese for a moment. There is a big difference in what these two groups of people eat even though they reside in the same country. Look at the Asian folks who migrate over here to the U.S. It doesn't take long for them to suffer the same adverse health issues as American born citizens.
Food industry feeds us a lot of ongoing propaganda regarding many of their money making foods. Let's look at the 'drinking wine is healthy due to the antioxidants' one. Now what they don't tell you is to get said antioxidants, which by the way you can easily get by eating berries and other fruit, is that you must cut through the wine's sugars, calories, pesticides, herbicides, fungicides, and fertilizers all used when farming the grape crop and all of which contain MSG, and last but not least is the extremely, extremely estrogenic and toxic alcohol within the fermented fruit. They don't tell you that part do they? Nope.
Before you gasp and think that I'm such a radical because I'm saying to never drink alcohol simply consider the exact health benefit or non-benefit the substance actually provides. Everyone can make their own choice in that case, but there are always risks and consequences no matter what you put in your mouth- good or bad.
Stick close to nature as possible. When you stray too far or manipulate it too much you will always experience something negative- small or great. Nature has a balance in it for a reason. I encourage you to educate yourself on the food industry propaganda and overall what and where exactly your food comes from and does to your body. Michael Pollan has great resources and books. Read "In Defense of Food" and "Omnivore's Dilemma" and these will shed some real light on that subject. Let's always continue to enlighten ourselves and our community.
We should never sacrifice anything for convenience when it comes to our health and our body. It takes effort and work. There is no way around that. What you put into something is exactly what you get out. If you work hard on your health both in exercise and nutritionally only then will you truly experience great results.