Why Martial Artists Shouldn’t Have Soy

By Christina Major  |  2 February 2021   

Soy protein drinks are all the rage in the martial art world. Steeped in the mysticism of Asia, soy has a reputation for replacing meat in a vegetarian diet.

But, just because it sounds good doesn't mean it actually is good. If you're consuming soy products in the US, chances are, you're doing your body more harm than good and negating your progress if you are following "The Fighter’s Nutritional Blueprint: Creating a Combat Arts Ready Body."

The History of Soy Around the World

Soy, soybeans, and fermented soy products seem to be a staple throughout Asia. But, that is a mysticism that's far overblown. According to the landmark study, then turned into a book, The China Study, Asians eat comparatively little soy compared to Americans. In fact, a typical vegetarian will consume between 12 and 16 oz of soy products per day—the typical Asian eats less than four ounces.

And there is one other big difference. In Asia, all soy is fermented. This includes tofu, natto, miso, and dozens of other products. Only edamame, raw soybeans remain unfermented; however, raw soybeans are a rare treat.

Without being fermented, soy is incredibly dangerous to the human body. It's easy, cheap, but certain things just cannot be overlooked.

Why Soy Is Horrible for Martial Artists – Especially Female Athletes

When we're talking about soy here, we are talking about unfermented soy products. These are soy isolates, soy protein drinks, soy protein bars, and chemically produced tofu and vegetarian products. They are marketed to a health-conscious person but will have the opposite effect.

Biologically, soy disproportionately affects females more than males. Some of the chemicals within soy mimic estrogen, throwing off the natural hormones in the body. In women, throwing off this balance has greater effect than it does in men.

In particular, this affects breast tissue. For women, it dramatically increases the risk of breast cancer. In men, it can cause fatty deposits over the pectoral muscles, creating a breast. Although there are several causes of the 'man boob,' soy is one of the top causes.

And then there's the cancer aspect. Although for a long time soy was touted as a food that can help replace meat because meat was so bad for the body, now we are discovering soy is much worse.

Soy and the products they come from are directly linked to the onset of multiple different types of cancer, including:

Another aspect of soy that may contribute to the cancer risk is the prevalence of GMO soy. Just about every product you will purchase is genetically modified. Some studies have shown that in nearly every product tested, some residue of pesticides and other agricultural chemicals remained. Many of these chemicals, like RoundUp, are known to be carcinogenic.

Finally, the biggest concern with soy is the goitrogens. These are a specific set of androgen-like hormones that are highly concentrated in the soybean.

During fermentation, these goitrogens are broken down. Fermentation plus a low intake of soy means that Asians do not experience cancer and thyroid problems like Americans do who eat unfermented soy.

What these goitrogens do is interfere with thyroid production and utilization. In some cases, they block the thyroid's ability to produce hormones. This inflames the thyroid and lowers your energy levels. In other cases, it interferes with the working of the thyroid hormones produced. As thyroid hormones have a primary focus on energy and metabolism, it's directly impacting your ability to work out and train properly. check out our article The Seven Foods a Martial Artist Should Never Eat.

So, Why Do They Say Eat Soy to Prevent Cancer?

You probably have noticed that doctors and many big hospitals produced literature that says soy can help prevent cancer. Why is there a difference of opinion?

It stems from the way the studies on soy are conducted. First significant detriment to most of the positive soy studies is that it is conducted on people who self-report their soy consumption but follow few other health markers. Scientists don't know if soy is why there is a lower breast cancer risk or if another factor, like exercise, might play a bigger role.

Although they consume soy more consistently in Asia than in the US, they get more exercise and eat a higher percentage of vegetables than in the United States. Additionally, the soy is fermented. The higher number of vegetables and the use of fermented soy negates the phytoestrogenic components and goitrogens.

Other studies follow a select group of women for a limited time to show breast cancer risk. Opponents of these studies say the studies were not conducted over a diverse population nor for the appropriate length of time.

Follow the Scientific Studies

More longer running studies are now showing breast cancer, heart disease, overall health problems increase the longer a person consumes soy in the US.

Finally, the majority of studies are conducted on isolated soy isoflavonoids given in specific concentrated doses. They do not factor in the other phytonutrients, phytoestrogens, or goitrogens that harm people. These studies don't look at real people eating real soy processed foods.

You don’t need soy, even on a plant-based diet. Special Forces elite trainer James Wilks is a mixed martial artist who follows a nearly pure plant-based diet and restricts soy consumption. His training helps hundreds reach elite levels.

If you're using a soy protein supplement to help you build muscle and have energy, you're actually doing the opposite. Over time, your thyroid will be damaged, and your risk of cancer goes way up. Although, as a martial artist, you do not need protein drinks or supplements at all, if you are using a soy drink, it's best to stop now.