Where soy got its bad name from and why it’s safe to eat it

Soy has been the centre of discussion for years now. Some argue it contains female hormones and we should not consume it as it can affect our own hormones. Others will counter that this claim is not true and that soy is safe for consumption. What is true? To answer this question we have to go back a couple of years to find out where soy got its bad image from in the first place. 


Early research on soy

In the early stages when soy was just being tested and experimented with, researchers found a substance that made them pause. Soy seemed to contain the female hormone estrogen! The findings the researchers published soon caused a lot of sensation. When soy contained human estrogen, did this mean it could potentially be harmful? Soy was a hot topic and talked about a lot. The media, food experts, supposed sufferers and other researches all had their say about it. And by that time there wasn’t a single soul without radio, newspaper or television who had not heard about the findings in soy. 

In the research world in the meantime, the original study was repeated and expanded like it is always done with research findings to make sure findings are indeed valid. Valid means that findings are true and other studies can replicate the original study and will get the same outcomes. Surprisingly the newer studies did not get these same outcomes. Instead they looked at the supposed estrogen closely and concluded it wasn’t estrogen what they were looking at, it just looked a lot like it. A series of more and more research started and throughout the years they were able to solve the puzzle. Unfortunately the newer findings did not manage to create as much sensation as the original study which is why soy is still suffering under the image of its very first findings today. 


What research knows today

The substance originally found in soy are isoflavones. Something that is now called “plant-estrogen”. They look like our human estrogen but are thousands of times weaker than human estrogen. It is also found in flax seeds and grain products though soy still has the highest quantities. Researchers have declared products that contain isoflavones safe for consumption. For soy it is advised to not consume over 4 servings per day. One serving being 100 grams of a soy product or 1 cup of soy yoghurt or milk. Normal soy also has less isoflavones than manufactured products like soy protein. Also miso, tempeh and other fermented soy products contain higher concentrations and are best not to be eaten daily. The general advise, as usual, is to just not overdo it. Although isoflavones aren’t strong, with a high intake they can still affect the fragile hormone regulation in our body. 


What happens when you overdo it on the soy products 

Overconsumption of soy is possible, as it is with any food, and has its consequences. Very rarely a case study pops up where men developed symptoms after eating soy products. Let’s look at two of them: A while ago a 60 year old man developed a condition where his breast tissue grew as a result of consuming soy products. It was later found that he drank almost 3 liters of soy milk a day, accounting to over 11 servings. Another case was reported of a 19 year old vegan man who suffered from hormonal dysfunction, loss of libido and erectile dysfunction after he had been consuming over 14 servings of soy products a day for a long period of time.

As you may be able to tell, overdoing it on the soy is probably not a good idea. 


Why you should eat soy

We are soy fans! Not only is it very affordable and easily accessible. It is also fairly tasteless on its own, much like plain chicken breast and it can be used in exactly the same way. Marinate it and bake, wok or fry it and it will taste exactly like you want it to. It is absolutely foolproof! Even if you are not a star in the kitchen. 

If you are working out you might be interested to hear that soy is one of the only plant products that contains a full set of amino acids and is thereby very easily absorbed by the body and supports muscle growth and recovery. And it does more for your insides too: research suggests that in countries where soy is regularly on the menu (like in Asia), much less causes of breast and prostate cancer, heart disease and bone fractures are reported and linked to their diet. 



Although it had kind of a rough start, soy is completely safe to consume in moderate quantities. With everything in life, it’s best not to overdo it. But does that mean soy deserves its bad status forever? We don’t think so. Carrots are awesome for your eyesight but when you eat a bag of carrots a day your skin will turn orange from all the beta-carotene. Ginger is a huge immunity booster, but if you drink more than 4 ginger shots a day, you might experience nausea. Mushrooms are found to help prevent breast cancer in women. But if you eat a lot of them every day they can be toxic. You get the most of every product you consume if you eat it within a healthy diet full of variety and other products. 


Written by Maritza Kolenbrander, Food Psychologist at Plantifulplan


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