What is the truth about soy? You’ve probably heard a range of things that has varied over time. Have you also been hoping that someone can finally answer: Is soy good or bad for me?
Why Soy Is a Smart Protein Choice
- It is a complete, clean, plant-based powerhouse.
- Complete plant protein – All 9 essential amino acids
- Highly Digestible: 90–95%, on par with animal protein
- Gut-friendly: Prebiotic carbs
- Healthy Fats: Contains both omega-6 and omega-3
- Sustainably sourced – Non-GMO Soy
If any of those make you go hmm… fair. Honestly, same – been there, done that. There is such a variety of information out there on soy. I’m excited to dig in and share what I’ve found that’s changed my perspective.
Mythbusting: Let’s find the truth
When I was a new mom, I leaned hard into soy milk for our first born because he was lactose intolerant. And then shortly after, I read a lot of (mis)information about how soy was bad for boys. For years I blamed myself for the fact that he was short because I’d given him soy milk.
Later, I remember crying because after being on a super strict autoimmune paleo Whole 30 protocol, I’d drank tea without realizing it had soy lecithin and thought I needed to start the clock completely over again.
Then, like all diet culture myths, the shame bubble burst with a flood of science that proved soy as a health food and nothing to fear. Turns out, the earlier studies in animals couldn’t be proven in humans. (2) And that it, in fact, helped human health.
While animal studies have raised valid concerns about [soy’s] endocrine activity, robust human data consistently refute their classification as endocrine disruptors or harmful to health.
I’m sure you, like me, are still struggling to make sense of it all, so let’s look at the science.
Myth: “Soy messes with your hormones.”
Truth: Soy helps health, including hormones.
If you look at older science, in 2019 the NIH published that the estrogenic affect of soy may have endocrine disruption. And then in 2025 rebuked themselves, publishing the “debunking the myth on soy isoflavones” (2)
This all centers around the fact that humans aren’t rats. When experiments were done on humans it debunked what was once only previously shown in limited animal studies.
Those scientific studies now debunked, we have rigorous studies that prove eating or drinking soy has no negative effect on hormone levels in neither men nor women. And in fact, it can help regulate hormones in a positive way – especially for women over 35!
It has been seen as having potential health benefits, such as reducing menopausal symptoms, improving bone health, and preventing hormone-related cancers. And now we know that “soy isoflavone supplementation is beneficial in both perimenopausal and postmenopausal women, more so in perimenopausal women” (3)
Fun fact: Japanese American women have less hot flashes than European American women (5)
Myth: Soy is bad for men.
Truth: Meta-analyses show that soy is not bad for men and may even offer health benefits.
Details: A lot of misinformation exists about soy and men’s health, particularly around concerns of it potentially lowering testosterone or affecting fertility. While soy contains isoflavones, which are sometimes called phytoestrogens, they do not act in the same way as human estrogen. They do not feminize men or reduce testosterone levels.
Multiple studies and a meta-analyses of 41 studies (1, 2020) show that soy consumption does not negatively impact testosterone levels or fertility in men.
Regardless of the statistical model, no significant effects of soy protein or isoflavone intake on any of the outcomes measured were found. Sub-analysis of the data according to isoflavone dose and study duration also showed no effect. This updated and expanded meta-analysis indicates that regardless of dose and study duration, neither soy protein nor isoflavone exposure affects TT, FT, E2 or E1 levels in men. (1)
Over 50 studies found no adverse effects of soy on testosterone in men. And, in some cases, even lead to improved testosterone levels.
Additionally, studies suggest soy can help actually reduce the risk of prostate cancer, lower cholesterol, and protect the heart. In fact, the 2020-2025 Dietary Guidelines for Americans recommend (4) including soy products as part of a balanced diet.
Myth: “Soy isn’t a complete protein.”
Truth: Soy is one of the few plant-based proteins that IS complete, meaning it has all 9 essential amino acids needed for muscle growth, repair, and energy.
Myth: “Soy causes bloating or digestive issues.”
Truth: High-quality soy has most of the fermentable carbs removed, making it easier to digest. I would also add that science has come to show how important microbiome diversity is. If you have a hard time digesting something, it might be related to a lack of stomach acid or a lack of gut flora to properly process it.
Soybean is the most economically important legume globally; it offers a high-quality, cost-competitive and versatile base-protein ingredient for plant-based meat alternatives. The health benefits of soybean and its constituents have largely been attributed to the actions of phytoestrogens, which are present at high levels. Additionally, consumption of soy-based foods may also modulate gastrointestinal (GI) health, in particular colorectal cancer risk, via effects on the composition and metabolic activity of the GI microbiome… clinical evidence suggests that some soy foods provide favourable changes in measures of GI health (7)
I had digestive issues reintroducing legumes after avoiding them for years. I loved using the Shaklee Soy Life Shake as a means of reintroduction to help with digestion. It includes digestive enzymes and is such a clean source. Start small and work your way up to adding more legumes to build back those little gut friends. I now crave and love eating lots of fiber-rich legumes!
Myth: “All soy is GMO and highly processed.”
Truth: Not all soy is GMO. Shaklee only uses non-GMO soy protein isolate that is carefully sourced and vigorously tested.
My Personal Perimenopause Experience
For nearly two years my menstruation has been getting progressively worse. Perimenopause brought the usual unpredictability, which is it’s own kind of pubescent fun. But it also brought a very heavy cycle, shortening my period to essentially 36 hours with incredibly heavy, painful, clot-filled flow. I had to ask Matt to help me function those days by bringing me a heating pad and allowing me to be horizontal for a day.
And then when I started partnering with Shaklee, I started incorporating the soy Life Shakes and…things changed. I noticed such an improvement that I ensured I included it in rotation a couple times a week and daily the week before my period. And while my menstruation still wasn’t a blissful, lovely experience, it was so much better.
Then, I ran out and didn’t have it for a while.
I honestly forgot how bad it had gotten until last month. Because of travel I’d gotten off routine and out of habit of having my daily smoothie. Listen, no one’s perfect, right? And woah – did that cycle hit me like a TON of bricks.
Last month you were completely debilitated, and practically unable to function. And then suddenly this month *wild hand motion* you’re completely functional. I wouldn’t believe it if I didn’t see it! – Matt, my spouse
It was so bad I got a doctor’s referral for a trans-vaginal ultrasound to check for cysts or fibroids. I was given the all clear – and that’s when I realized, it was the soy. So I got back into routine, now switching to a daily Soy Life Shake since the new formula* has the Methylated Bs that I wanted from the Plant version.
I kid you not, as Matt describes, this period was night and day from the last.
Now, this is my own personal experience – not medical advice. AND I can tell you I’ve talked to a LOT of women who also have similar experiences. I’ve heard testimonials on dry skin improvement, mood stability, and all kinds of menopausal symptom relief that aligns with the study results above.
*Why Life Shake
For me, Life Shake is an easy way to consistently get my needs nutrient needs met, especially now that the soy formula has methylated B vitamins and a whole host of other nutrients that help me start my day.
I’m happy to chat more about why I love Life Shake. But, ultimately the short answer: it’s clinically proven absorption, safety tested for contaminants, and new research that allows Shaklee’s Life Shake™ is clinically shown to:
- Be non-inflammatory
- Naturally boost GLP-1 levels in just 30 minutes, helping to promote satiety and curb cravings
- Help support healthy hormone levels
- Provide highly absorbable protein (and 25 other essential vitamins & minerals)
I also love that they have an empty bottle guarantee. I even give a recipe guide if you grab it thru my referral link (which also gifts you 15% off, here).
Whether it’s Life Shake, edamame beans, or another form – give soy a try! What do you have to lose?!
Want more validation?
My friend and medical bio physicist Dr. Sarah dives deep about soy here (6) and shares more about how it helps our health in these two soy-based educational videos:
@drsarahballantyne Replying to @LC Eating more soy reduces the risk of type 2 diabetes and cardiovascular disease! #nutrivore #soy #tofu
@drsarahballantyne Soy products (bit not soy milk) for menopause symptoms #nutrivore #nutrients #soy #soybeans #menopause #hotflashes #nightsweats
Resources
- Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies, PMID: 33383165
- Debunking the myth: are soy isoflavones truly a public health concern? PMC12303811
- The Impact of Soy Isoflavone Supplementation on the Menopausal Symptoms in Perimenopausal and Postmenopausal Women PMC9583364
- 2020-2025 Dietary Guidelines for Americans
- Do Japanese American Women Really Have Fewer Hot Flashes than European Americans? The Hilo Women’s Health Study PMC2746710
- Nutrivore, Soybean Nutrients
- Soy and Gastrointestinal Health: A Review, PMC10144768
This is my own personal opinion and not medical advice. It’s always good to discuss choices to your body – external and internal – with a licensed professional.
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