Soy. There has never been a food item with such debate as there is with soy. Soy has been toted to be incredibly beneficial for heart health, hot flashes, preventing breast and prostate cancer, helping with weight loss and preventing osteoporosis. While at the same time, there have also been claims of increased risk of breast cancer and minimal help in heart health.

So, where does the truth lie?

If you do a quick Google search on this topic, you’ll see that most are divided on their opinion, as is the research.

That makes it sound pretty grim, but there is some light when you break down where we are on soy research. Let’s start at the beginning: why is soy thought to be beneficial?

There are phytochemicals within soy called phytoestrogens, specifically isoflavones. These isoflavones, along with fiber, are what aid in the beneficial affects. Once you have eaten any soy item, your body metabolizes it a few different ways. There are two different types of receptors that your body uses to do this. Looking specifically at breast cancer, studies have shown that when women were introduced to a high soy diet before  puberty, there have been beneficial effects at decreasing the risk of breast cancer. This happens due to how the estrogen is metabolized and increases a certain type of estrogen receptor. The introduction of soy post puberty/menopause showed less to no beneficial effect at decreasing the risk of breast cancer. There were some studies that showed when a different estrogen receptor was activated there was a possible increase in free radical production. This free radical production could affect many different cells, but has been postulated to affect breast tissue, thus increasing risk of breast cancer. The claims of these studies have not been supported by other researchers’ findings. This is where much of the fear of soy resides.

Confused yet? Soy is one of the world’s biggest enigmas of science. There is no definitive answer within the research to say that it is evil – or a godsend. So, what to do with this conflicting information? If you are a hypochondriac, like me, you avoid most processed soy (I don’t know what kind of receptors I have and I am a vegetarian that was completely dependent on soy for a few years). With that said, that’s just me. We are all different, and need to remember that when discussing food items to include or exclude from our diets.

If you decide to keep soy in your diet, here are a few recommendations on what types to eat and what types to avoid:

Soy to Include

You always want to choose whole food options at every opportunity you can. The food choices to make here are non-GMO organic soy options, as well as those that have been fermented. These include edamame, miso, kimchi and tofu.

Soy to Avoid

The soy options that should be avoided, for multiple reasons, are those that have been heavily processed. These food items include soy-isolate proteins, meatless soy foods (burger patties, chicken nuggets, etc.), soy cheese, soy ice cream and genetically modified soy.

If you are still having concerns about whether you should or shouldn’t eat soy, talk more with your doctor. If you ensure you are doing what is right for you and not listening to what others say, you will be making the right choices.

What is your opinion on soy?

Image via Hart & Honey



  1. This is a bit case-specific, but you may not be aware that phytoestrogens can be bad news for those suffering with an underactive thyroid gland (hypothyroidism). Estrogen has the effect of increasing the binding of thyroid hormones, whether endogenous (produced by the body) or exogenous (taken as a prescribed supplement), meaning that less of the hormone is actively available in the body. At the very least, hypothyroid patients should be very careful about the amount of soy they consume; at most, they should consider avoiding it altogether.

  2. Hi, there–medical student/MPH here–I agree with 99.9% of what this article says, the gist of which is similar to all good dietary advice: avoid processed foods, eats more wholesome foods. The only line I have an issue with is where the article mentions to avoid genetically modified soy. If there is any debate that is even more contentious than the one on soy, it is this. Most research backs the safety of genetically modified foods–and, indeed, most of the fresh vegetables and fruits even at a farmers market would fall into this category. To avoid genetically modified foods is a decision based on attitudes toward environmentalism and health that are more personal than scientific.

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