Kris Carr

Kris Carr

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Understanding How Soy Foods Impact Your Health

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Hi Sweet Friends,

Oh, boy, we’re talking about soy.

It’s a hotly debated topic these days, especially in the plant-based community. You’ve probably heard mixed reviews on this elusive bean—some good, some bad and some very ugly. I know it can be frustrating, but don’t throw your tempeh piccata in the trash just yet. With a little extra smarts, you can make an educated decision on how, why and if soy should be part of your diet. I certainly include it in mine, but that doesn’t mean I’ll be signing up for a soy-dog-eating contest anytime soon. As you’ll learn in today’s blog, organic, non-GMO soy foods can provide many benefits when eaten in moderation.

What types of soy foods are best, and how much should you eat?

In my fridge, you’ll find a variety of whole and minimally-processed soy foods, such as edamame, tempeh, miso and tofu. These foods land on my plate 2-3 times per week, although I tend to use tofu the least since it’s one of the more processed choices in my soy repertoire. They’re all rich in nutrients, antioxidants, protein, essential omega-3 fatty acids and phytoestrogens. A word to the wise, almost all soy is genetically modified. That’s why I always buy organic and search for the non-GMO label. It’s best to look for both stamps of approval, since organic does not guarantee 100% GMO-free food.

Eating soy as nature intended (or very close to it) can be beneficial to your well-being in a variety of ways. Soy protein and omega-3s are important for heart health. They also keep your arteries clear and cholesterol levels low. And contrary to some unsubstantiated fear-based claims, phytoestrogens may actually help reduce breast cancer risk among premenopausal women (more on soy and cancer in the following section). In addition, whole soy foods are easier to digest and taste better than their processed cousins. Plus, the microflora in fermented soy products, such as miso and tempeh, are your belly’s BFF.

Again, keep processed soy foods (and processed foods in general) to an absolute minimum. You’ll often find soy protein isolate or concentrate — both at the top of my list to avoid—on their ingredient lists. Faux chicken nuggets, soydogs and other fake meats not only contain processed soy, but a laundry list of food additives and preservatives as well. While these foods aren’t the devil, they certainly aren’t real, and therefore should never be a dietary staple. Think of them as an occasional novelty. The one exception I’ll mention is for those transitioning from a meat-heavy to a plant-happy diet. Eating faux meats and cheeses as a crutch can be helpful, but they definitely shouldn’t hold center stage for long.

 

We often cling to processed soy foods because of our culture’s protein paranoia.

News flash sweet friends — protein doesn’t need to be the main event on your plate at every meal. Now I’m not saying that you don’t need protein, you absolutely do. But if you’re consistently eating a varied, plant-based diet, filled with beans, legumes, nuts, seeds, grains and vegetables, you’re in good shape! And with such an abundance of protein-rich choices in the plant family, are you starting to understand why soy is optional?

If you’re still concerned about protein, simply calculate your daily requirement using the following formula: Your body weight (pounds) multiplied by .36 equals the amount of protein (grams) needed for a moderately active adult. For example, a 140 pound person needs about 50 grams of protein per day. Here are just a few of the high-protein plant foods out there: one cup of lentils contains 18 grams of protein, one cup of quinoa contains 8 grams of protein and two tablespoons of almond butter contain 7 grams of protein. See how easy it can be to meet your protein needs?

Soy seems pretty straightforward when you’re talking about quality and quantity, but the conversation gets trickier when you begin to explore the claims flying around about soy and certain health issues. Next up, soy dangers demystified!

Is there really a link between soy and cancer?

You may have heard that eating soy increases your risk of cancers such as prostate and breast cancer, but the opposite may be more likely. Recent research has shown that lung cancer patients with a history of eating soy have a better survival rate than those who have eaten less or no soy in the past. Men who consume soy have actually been found to have a reduced risk of prostate cancer. And then there’s the most frequently misunderstood relationship — soy and boobs.

When a woman regularly eats protein-rich and phytoestrogen-rich soy foods, studies show that her breast cancer risk drops. Soy’s potentially protective role may be due to its isoflavones which are phytoestrogens (literally meaning “plant estrogens”) and may block some of estrogen’s activity. It could also be the result of various anti-cancer phytochemicals in soybeans. To get the maximum benefit of soy’s protection, some studies show that healthy soy foods should be part of the diet during puberty and adolescence when breast tissue is forming. But that doesn’t mean that you should go soy-crazy. As we’ve discussed, quality and quantity matter. For example, the ladies who participated in the original studies connecting Asian women’s lower breast cancer risk to their regular soy consumption were eating small, moderate amounts of whole or minimally processed soy foods (not buckets of soy jerky!).

So why are people still concerned about soy when it comes to estrogen-sensitive diseases like breast cancer? We’re still not sure how much soy is safe for individuals such as breast cancer patients and survivors, so doctors often recommend that their patients play it safe by avoiding soy completely. This is a very common approach because hormone-sensitive cancer receptors are stimulated by human estrogen and the structure of soy is similar to human estrogen. At the same time, eating soy foods can actually be beneficial to these types of patients and often recommended to patients in moderation during hormone blocking treatment. And it’s also important to mention that soy supplements (not soy foods) are frequently used in the animal studies that point an accusatory finger at soy and cause alarm.

In Life Over Cancer, Keith Block, Oncologist MD, states that based on his review of the current research, “both premenopausal and postmenopausal women with ER+ tumors can safely eat soy foods such as tempeh and tofu about two or three times per week.” Interestingly enough, many of the same doctors who tell patients to avoid soy altogether never mention the abundant amounts of estrogen and other growth hormones found in meat and dairy products! So if you’re avoiding soy as a result of a cancer diagnosis, think twice about animal products as well.

What about soy-loving fellas?

Good news for boys and men! Despite the buzz that “girlie” phytoestrogens may have a negative effect on hormones and fertility for males, there isn’t a single study showing this—nothing linking these issues to soy formula for baby boys or tofu burgers for boy scouts—nada. In fact, a huge study published in 2009 showed that soy food consumption actually reduced prostate cancer risk by 26 percent among soy-strong men. If you’re pregnant and concerned about soy affecting your baby boy, remember that any studies on the subject have involved animals consuming “large” or “high” amounts of soy—not something that fits into our model of eating a moderate amount of unprocessed, whole soy foods.

If you’re concerned about male reproductive issues, it might be time to look more closely at your dairy consumption. A recent study found that consuming high-fat dairy products like cheese and sour cream may lower sperm quality and fertility, perhaps due to the naturally occurring reproductive hormone, pesticides, chlorinated pollutants and/or heavy metals present in dairy foods.

Does soy impact thyroid health?

Another soy misunderstanding: Much like the confusion surrounding cruciferous veggies and thyroid function, soy isoflavones do not cause hypothyroidism or exacerbate hypothyroidism. Research published in the Journal of Clinical Endocrinology and Metabolism studied two groups of women: one group with 2 mg of phytoestrogens (plant estrogens in soy) and one group with 16 mg of phytoestrogens. They found a small percentage of the high-soy intake group had some decrease in thyroid function, but it should also be noted that the high-soy intake group also saw significant health benefits from this increased soy consumption, such as decreased insulin resistance, decreased inflammation markers and lower blood pressure.

You should be aware that soy isoflavones may absorb some of the iodine needed to make thyroid hormones, which could increase the body’s need for iodine. But, as long as iodine intake is sufficient, soy shouldn’t be a problem for the thyroid. Iodine is especially high in sea veggies, which means that miso soup with tofu cubes and wakame seaweed is not only a soothing combo, but also a match made in thyroid health heaven.

Please note that soy foods may affect the absorption of meds used to treat hypothyroidism. If you take medicine to treat hypothyroidism and love soy, check with your doctor so that your dosages can be adjusted accordingly. And still eat seaweed — it’s good for you!

If soy isn’t a great fit for me, what are the best alternatives?

While soy can be a convenient and healthy part of your diet, know that if you’re allergic (soy allergies are quite common), feel congested after eating it or need to avoid soy for other reasons, it’s not an essential part of a plant-based diet and can be eliminated without compromising your health. As I mentioned earlier, plant protein and essential fatty acids are found in a variety of beans, lentils, nuts, seeds, quinoa and whole grains. And soy-free milk, cheese and meat alternatives are widely available today. Be a label detective and choose products with a short list of ingredients you can pronounce. I opt for a variety of nut, seed and grain-based alternatives, such as almond milk, hemp milk, flax milk, nut cheese and grain meat.

For more soy schooling, check out these highly researched and credible resources:

Whether or not you decide to include soy in your diet is very personal decision that only you can make, but hopefully you feel much more prepared to make that choice with this knowledge under your belt.

Peace & edamame,

Add a comment
  1. Aditi says:

    It’s a nice and helpful piece of information. I am glad that you shared this useful information with us. Please stay us informed like this. Thanks for sharing.
    Adisoy is the manufacturer and supplier of premium quality soy products that enhance health on one hand and treat your tongue on the other. Go to any nearest outlet and grab a pack of Milsoy, Fitsip, or treat yourself with Tofood or Yobite. All soy products are available @Adisoy.in

  2. Cait Grant says:

    This article is wonderful! I was just talking with a friend about soy and whether it is good for you or not. I mentioned to her how hard it was to find reliable resources, especially on the internet, where every article seems to tell you the opposite! Thank you, again, Kris!! 🙂

  3. Chris says:

    Heya,
    what´s about Soy yogurt? Is that ok?
    Best Wishes…

    PS: I really love your books!

  4. Annie says:

    There are so many benefits that we get from eating soy products 🙂 I guess we just need to consume it in reasonable amount if we want to avoid the negative sides.

  5. Gordon Graham says:

    My doctor who is trained in both Chinese and Western medicine, told me straight out: unfermented soy like tofu is indigestible by humans. It takes a ruminant with multiple stomachs like a cow to digest it. Plus it contains a lot of unhealthy stuff, as you noted in your piece. On the other hand, miso and other forms of fermented soy can be taken up by humans because it’s already “pre-digested.” Looking into this further, most scientific studies don’t distinguish between the two forms and lump them all in together.

    Not being a trained biologist, but suspicious of any huge agribusiness that spends millions on marketing (like the soy industry today, check it out) I’ve completely eliminated soy from my diet and I don’t miss it one bit.

    The paleo people say beans in any form are not digestible, and I tend to agree. I’ve known several people who went into extreme vegan diets dependent on beans and soy, and they gained weight they could not lose.

    So my policy is “moderation in all things.” I’ll eat beans and legumes once in a while, but I have stopped depending on them for protein.

  6. Christina says:

    Where does soymilk fit into this mix? I tend to purchase only organic soymilk Does anyone have a few brand suggestions? The grocery story I go to sells Silk and 8th Continent brands.

  7. ADane says:

    Great article! I’ve been confused about soy and have been leaning towards taking it out of my diet all together. This article helps me to see a vision of balance! 🙂 What’s your take on organic soy milk? I can’t do dairy and not many cafes offer my favorite option which is almond milk…so I opt for some soy milk 1-3x/week but want to be making healthy choices when it comes to soy. I avoid the soy isolates as you mentioned. Where does organic soy milk fall on the continuum of good vs not-so-good soy foods? Thanks!!

  8. Lisa says:

    I’m not so sure I believe soy is good for you. Dr. Mercola http://www.mercola.com has many articles why it should NOT be consumed, unless it is fermented.

  9. Karen Mitchell says:

    Smart, informative information! Thank you, I would like to know more about your organization. Is your information strictly in print or is it also on electronic media.

    Thank you,
    Karen

  10. Thanks for this awesome article, Kris! As the soy debate rages on, it’s great to have a perspective backed by scientific research. I’m particularly intrigued by the thyroid health section and the relationship between soy isoflavones and iodine. Good stuff!

  11. gina says:

    I have been confused on the talk about the negative effects of soy. i read the book The Okinawa Program and they have the highest number of centurians who are healthy and they also have some of the lowest rates of camcer but they eat soy. So i don”t understand the difference?

  12. Sheri says:

    Hi Kris and all,
    I’ve found conflicting info. on the average amount of protein humans (and even dogs) need.
    I saw somewhere the equation .39 per pd.? I also read 50-70 grams a day. Is there an easy way to understand this and also to explain it, with studies to back it up?
    With gratitude,
    Sheri

  13. Judy says:

    Hi. I have really been enspired by your love for life. It has been a mazing journey for you. I’ve startedy journey eat a plant based diet and I’m a maze how are body function really well. I think I was borned to be a vegetarian but it is hard when your husband wants meat at almost all meals. I was going to start your green juices but was wondering what you think of this juicers for starters. HUROM PREMIUM VERTICAL COLD PRESS JUICER – HU500
    Thanks,
    Judy

  14. Natasha says:

    Thank you for this article Kris! Any thoughts on Bragg’s soy seasoning/liquid aminos?

    Cheers,
    Natasha

  15. Robyn says:

    Thank you for this – I bought soy milk for the first time this week and was unsure on how often was suitable to have soy products! SO thank you! 🙂

  16. Tricia Whelan says:

    As a holistic nutritionist (including Certified Vegetarian Nutritionist) I am a great fan of whole organic soy foods including organic tofu. It has been made for centuries in the kitchens of Japanese and Chinese women so it technically is not highly processed although more processed than tempeh and miso.

    The deadly soy found in protein powders, soy baby formula’s and fake cheese and fake meat needs to be avoided. Any isolated or concentrated protein powder (soy, whey, hemp, rice, pea) is always a source of MSG. Check out http://www.truthinlabeling.org for more information. When these proteins are processed the amino acids often reformulate into a neurotransmitter (MSG.) a virus or a hormone. They are also difficult to digest and cause digestive disorders and eliminative tract disorders including cancer of the digestive tract. There is a Proctologist in our city that says these protein powders keep him in business because they destroy the digestive system. Isolated and concentrated soy is processed in aluminum vats using acid and alcohol washes, infusing the final product with high levels of aluminum (remember the baby formula?) As a vegan, I have more than adequate protein from my whole food plant based diet. Eat real food!

  17. mary soderiou says:

    Thank you for your soy article….as always a very confusing topic though i think you have clarified the confusion: don’t eat processed or GMO soya beans and eat in moderation.
    You have not mentioned soya milk , i drink Bonsoy, (not sure if it is available outside of Australia)which uses whole organic beans, tapioca syrup, job’s tears and calcium carbonate. I try ot moderate it, but it is soooo yummy, especially in chai…is soya milk considered too processed to drink?????

    thanks Maryxxxx

  18. An important large study published last year analyzed the results of three population studies (2 US/ 1 Chinese) on breast cancer patients, each of which showed that soy isoflavone intake was associated with reduced risk of breast cancer recurrence and/or mortality.

    The 2012 analysis found that soy isoflavone intake of more than 10 mg/ day was associated with decreased risk of recurrence.

    Here’s the study:
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3374736/

    And here’s a helpful and short article from MD Anderson discussing it: http://www.mdanderson.org/publications/inside-integrative-medicine/issues/nov-2012.pdf

  19. Melanie says:

    Finally a great article & update about soy! Just like everything, enjoy in moderation. Thank you for reminding us that organic does not mean GMO-free. Soy is a HUGE Monsanto product & GMO’s should be avoided wherever possible!

  20. Alex says:

    Thanks for the article, very interesting. It doesn’t really mention soy milk, is that considered ok or is it highly processed too? My daughter is anaphylactic to dairy, so was put on soy formula at 8 months, and now drinks soy milk (she’s 3). I’ve always worried about it, but the dietician, allergist and paed all said it was fine. I discourage her from drinking much of it, and I buy one that says non-GMO. What do you think?

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