Is Soy Good for Gut Health?Tuesday Feb 28, 2023
Is soy good for gut health and just health in general? Depending on who you ask, you might get a different answer.
The pro-soy crowd will point not only to the many benefits it has on gut health (such as boosting the number of beneficial bacteria) but also the fact that soy contains many vitamins, minerals, and nutrients that are good for your overall health. Also, there's research that indicates soy may:
- Lower blood pressure
- Reduce the risk of coronary heart disease
- Ease menopausal symptoms
- Guard against breast and prostate cancer
But soy doesn't come without its detractors, who claim that consuming soy can negatively impact your health—causing digestive problems, reducing testosterone levels in men, and actually increasing the risk of cancer.
In this post, we'll be taking a look at what the science says when it comes to soy so you can get to the bottom of the positive or negative impacts consuming it might have.
What Is Soy?
Soybeans (which is where soy comes from) possess a full pallet of amino acids. In fact, it has all 9 essential amino acids. These are amino acids you must get through your diet because your body can't produce them on its own.
Having all 9 makes the soybean a complete protein, which is pretty cool, considering the limited amount of plant-based foods that are a complete protein source. Usually, you'll only find complete protein sources in various meats.
Aside from being a complete protein source, here are some of the other main health benefits of soy to be aware of:
- High in fiber—Fiber is a prebiotic that's essential to quality gut health. It also helps to keep you regular and prevent constipation.
- Rich in protein—Protein keeps you feeling fuller for longer, making it ideal for anyone on a weight loss diet. Eating protein can also speed up your metabolism. In fact, one study found that a high-protein diet can help you burn 80+ calories more per day than a conventional diet.
- Contains plenty of omega-3 fatty acids which have been shown to reduce the risk of heart disease, slow cognitive decline, and provide relief from autoimmune disorders like Crohn's and ulcerative colitis.
- It's great for those who have a food sensitivity to lactose, as it does not contain any lactose. So you can have foods like soy milk and soy yogurts.
- Soy contains an abundance of antioxidants that defend your cells against free radicals (which are harmful molecules that have a hand in things like heart disease and cancer). Two antioxidants soy is particularly high in are polyphenols and isoflavones (more commonly known as phytoestrogens).
Myths About Soy
Some people believe the following about soy:
- Myth #1: The isoflavones in soy can have an estrogen-like impact on the body and lower testosterone levels. This claim is especially concerning for men who don't want to become “feminized.” However, research shows this simply just isn't the case.
- Myth #3: It has a negative impact on your thyroid. While some animal studies may lower how well your thyroid functions, human research finds basically no impact on thyroid function, especially in adults with normal functioning thyroids.
- Myth #2: Consuming it increases your cancer risk. However, research shows this claim is unfounded. In fact, observational studies show that eating soy may reduce breast cancer risk by as much as 30%.
- Myth #4: It's harmful to babies. Parents may fear that formula made from soy can hinder child development. But research shows that soy consumption doesn't have this negative impact.
It's worth pointing out that any negative impact relating to soy typically only comes about due to consuming abnormally high amounts.
Also, it's worth noting that, in places like Southeast Asia (China, Japan, etc), soy has been consumed daily for thousands of years without causing these negative impacts that nay-sayers talk about.
What's the Link Between Soy and Gut Health?
Trillions of different microbes (both beneficial and some not-so-beneficial) inhabit your gut. And having a diverse set of “good guy” bacteria isn't just important for gut health but it can have an impact on many other aspects of your health. It can influence your immune health, mood, energy levels, and blood sugar. Gut health can even impact the skin.
It should be no surprise that the foods you consume play a key role in helping populate your gut with beneficial bacteria and research shows that foods with soy have a beneficial effect on gut health. In fact, research shows foods with soy to boost the number of bifidobacteria and lactobacilli bacteria, which are two types of probiotic bacteria that have been proven to be essential for gut and overall health.
But when it comes to soy and gut health, the thing to keep in mind is that not all foods with soy are created equal.
If you want to get the most out of soy and gut health, it's best to stick with foods that are as close to their natural state as possible (i.e. not highly processed). This includes foods like soybeans, tempeh, tofu, soy milk, and soy yogurts.
If a food is ultra processed, it can lose some of the vitamins, minerals, and nutrients it has, which means it may not contain as many health benefits. Also, highly processed foods typically have more things like sugar, fat, additives, and fillers you might not want.
Fermented soy-based foods are also good (so, think foods like soy sauce, miso, and natto). The process of fermentation cuts down on the antinutrients many soy foods have (antinutrients block the absorption of nutrients). A few other ways to decrease antinutrients in soy-based foods are by cooking, sprouting, and soaking them before eating (enhances digestion).
Soy isn't something you should be afraid of, especially now that you know about the positive impact between soy and gut health (and really, just overall health). It can boost the number of beneficial bacteria in your gut, it's high in protein, contains lots of fiber, and plenty of omega-3 fatty acids. So don't shy away from having a little soy in your diet!
About the Author
Chad Richardson is a freelance writer from Cincinnati, OH who also enjoys going to the gym and doing his best Arnold Schwarzenegger impersonation, scrolling through Netflix trying to find a new binge-worthy show, and catching a game to root on his hometown sports teams.