Is Soy Good For You?
By Nutritional Weight & Wellness Staff
April 29, 2024
Have you ever wondered...is soy healthy?
Once a client declared, as she raised her ubiquitous white and green paper cup, "This is decaf coffee with soy milk. I just wanted you to know." She was assuming we thought that was a good way to drink coffee.
And yes, it was great that she left behind the flavored syrups with high fructose corn syrup and the fake creamers with bad fats, but what about that soy milk and other soy foods?
Origins Of Soy
Originally, soy was used in Asia as a cover crop to enrich soil. It was much later that Asians used it to season and enrich their meals. In the West, soy was used first by industries to make paper coatings, glues and even as fire-fighting foam.
Around the 1950s, food companies started producing soy isolate and soy lecithin. Currently, you can find soy in many foods including soups, imitation meats, non-dairy creamers, infant formulas, cereals and protein powders. If you are allergic to soy, you know just how difficult it is to find foods that do not contain soy. It is everywhere.
Health Claims About Soy Foods
To answer the question "is soy healthy?", we've scoured the science to see if research suggests there are health benefits to safely consume soy or if there's a risk of developing health conditions like breast cancer, prostate cancer, cardiovascular disease, or other risk factors.
Some sources have suggested that soy protein and soy isoflavones can reduce cholesterol levels, and diminish hot flashes, one of the most common menopausal symptoms. Let's examine these claims more closely:
Soy Protein vs Animal Protein
Soy has been advertised as an inexpensive protein alternative, especially for vegetarians, in the form of soy protein isolate because it is high in protein and it contains all the essential amino acids, making it appear to be a complete protein.
However, the body cannot use soy proteins to make muscles, bones or hair as well as it can utilize animal proteins for those functions.
Soy & Heart Health Benefits
In 1999, the FDA approved soy as a food to reduce cholesterol levels and risk of heart disease; however, to get these health benefits the FDA recommends eating a pound of tofu daily (a serving size is 3 ounces)!
In 2005, the American Heart Association officially disagreed with their previous claim after reviewing many studies claiming soy's benefits. This panel also found that soy was not effective at reducing hot flashes or reducing breast cancer, uterine cancer or prostate cancer.
Soy & Hot Flashes
It has been believed that soy could reduce hot flashes, but in NIH's National Library of Medicine a systematic review of 62 studies published in 2016 said there may be modest reductions, but further rigorous studies were needed to determine whether plant-based therapies, including soy isoflavones, were helpful for menopausal health and menopausal symptoms.
An article published in 2022 by Frontiers In Nutrition in the National Institute of Health library titled "The Health Effects of Soy: A Reference Guide for Health Professionals" looked at the various studies on soy and hot flash alleviation over the last 30 years. The authors concluded, "Clinical trials evaluating the efficacy of soy isoflavones to alleviate hot flashes, which date back nearly 30 years, have produced conflicting results, which are reflected in the reviews and analyses of the data published over this time." They suspect that the variability in the type of soy ingredients tested has created mixed results and more specific, controlled testing is needed.
Soy, Infant Formulas & Puberty
Soy is also used in formulas for infants who are sensitive to cow's milk and are not being breastfed. There are concerns that soy infant formula may be contributing to the early puberty in girls and the late puberty in some boys.
Two recent studies in 2021 showed conflicting results: one team in Columbia DID NOT find a significant impact on puberty onset, while another team in Brazil DID find an association between soy consumption and early puberty, with those being breastfed to have a possible protective factor.
Studies also show that using soy formula may stress the immune system later in life. Interestingly, in 2005, Israel joined France, New Zealand, and Australia in recommending limited use of soy consumption in young children and if possible, avoiding it all together.
Is Soy Healthy?
As you can see, the consensus on the health benefits of soy is mixed. Which brings us to consider how the quality of soy food matters:
An important question: Is it highly processed?
One very important distinction we want to make in this discussion on whether or not soy is healthy is the spectrum of processing when it comes to soy products. Much like other foods, we have options for unprocessed whole foods or minimally processed foods on one side of the spectrum and we have ultra-processed foods that go through a whole chemical and mechanical processes in order to be edible.
When it comes to eating most soy products, it's best to stay away from the ultra-processed soy products, like plant-based meat alternatives, soybean oil, sweetened soy milks, soy yogurts, and even soy protein isolate in soy protein supplements (there are better plant-based protein powders you can choose, which we'll get to later).
If our dietitians and nutritionists are working with a vegan or very restricted vegetarian client, we will work some organic tofu, organic tempeh, and edamame into their plan to bump up their protein since these sources are minimally processed soy foods. Soybeans have the nine essential amino acids that make up a protein, so adding cooked soybeans to a soup might be a great protein option for vegans.
When To Be Cautious About Soy
At Nutritional Weight & Wellness, we recommend that our clients are cautious in their soy intake for several reasons:
Soy is difficult to digest, which can cause gas, bloating and general discomfort. Fermented soy products, such as miso, tempeh or soy sauce are more easily digested than non-fermented soy foods. If you already have a touchy gut, it might be best to avoid soy foods while you heal your digestive issues.
Ninety-four percent of the soy in the U.S. has been genetically modified —a process where a crop is altered by a virus or bacteria with a desired trait, such as resistance to a weed killer – according to the FDA. If you are choosing soy products, look for organic and non-GMO when possible.
Soy can interfere with thyroid function, which may affect your metabolism. If you are predisposed to thyroid issues, be cautious with soy intake to not exacerbate challenges with thyroid function.
Soy contains phytoestrogens. These are the chemicals that can mimic estrogen in your body. We mentioned the concerns about soy's effects on puberty and on the immune system that parents of newborns have. However, adults have other reasons to be wary of the soy phytoestrogens: the phytoestrogens in unfermented soy can block the absorption of minerals like calcium, magnesium and zinc. The soy milk, soy protein bars and soy protein powders that you may use to improve your health may in fact be preventing you from building strong bones (calcium), relaxing (magnesium) or preventing the flu (zinc). If you feel like you have estrogen dominance or have signs of mineral deficiencies, notice how many soy foods you are consuming.
Soy decreases sperm counts and testosterone levels. In 2010, Dr. Chavarro, M.D. from Harvard University, reported in the Journal of Human Reproduction that there was a strong association between men's consumption of soy and decreased sperm counts. Others have noted that testosterone levels decrease in men that consume soy. If you or your partner are struggling with infertility, try to avoid eating soy for a time to see if it makes a difference.
Let's Summarize These Findings
Soy may interfere with thyroid function. It is difficult to digest for some people and does not allow you to fully absorb minerals. Soy has an estrogenic effect—reducing fertility in men and it does not conclusively reduce hot flashes or protect you from reproductive cancers, like breast cancer or prostate cancer.
As an infant formula, effects of soy may cause early puberty in girls or late puberty in boys or stress the immune system. It really is not a complete protein that works in your body. So, soy milk in your coffee may not have any health benefits for you and may have some serious unwanted effects.
Use Soy Sparingly
Traditionally soy was used as a condiment in its fermented soy forms—as soy sauce, miso in soups, or small amounts of tempeh with rice and vegetables. Asian cultures use soy sparingly and traditionally. Processed soy like soy milk, soy protein isolate powders or protein bars do not exist in their diet.
Research reveals that health benefits of soy are inconclusive and eating soy foods may in fact prove to be harmful. If you would like to eat soy, do so sparingly, as a condiment or according to the recommendations of your nutritionist.
If you're vegetarian or vegan, consider a balanced approach by avoiding heavily processed soy products and choosing organic, minimally processed soy foods, especially the fermented soy foods we mentioned earlier.
What Can You Use Instead Of Soy Foods?
Protein Options
Look for animal sources like whey, beef, or egg which provide the most usable forms of protein for our bodies and contain all the nine essential amino acids. With our Wellness Whey Protein powder (comes in chocolate, vanilla and natural flavor), one scoop contains 18 grams of protein.
If you're looking for a dairy-free option, our Paleo Protein powder in chocolate or vanilla is a great tasting choice and gives you 21 grams of protein made from beef peptides with a full amino acid profile.
For those who are looking for a plant-based protein powder, it's better to go with a Pea Protein, which won't give you the adverse reaction we shared above while giving you an excellent amino acid profile for energy and metabolism.
Soy Sauce Alternatives
Because soy sauce also contains wheat, many of our clients who are gluten sensitive can't tolerate soy sauce. To add a salty, umami flavor to dishes you can use tamari, which is a Japanese sauce made from fermented soybeans with little to no wheat (check the label to make sure the one you are choosing is fully gluten-free). It has a darker, smoother, less salty flavor to soy sauce.
To skip the soy altogether, coconut aminos (also called liquid aminos and coco aminos) is a great option! It's made from the sap of a coconut tree and gives a similar umami flavor to your dish. It's slightly sweeter than sauces made from soybeans. It also has a lower sodium content for those watching their sodium intake.
Milk Substitutes
For drinking milk, if you and your family can handle dairy products, go for whole milk. Low-fat dairy products, such as skim milk, are deficient in vitamins A and D.
Since vitamins A and D are necessary for growth, energy, and learning, food manufactures fortify low-fat dairy products with synthetic vitamin A and D. Synthetic vitamins are never as beneficial as what occurs naturally in food.
When fat is removed from a product, usually carbohydrates or artificial ingredients are added for better flavor and mouth feel. Overall, it's better to choose full fat options. (For more information on choosing quality dairy products, check out this article: Getting Smart about Dairy Products.)
Dairy-Free Substitutes
What should you consider when substituting dairy for something else? Look at the label for added sugar, nutrient content, and any other additives.
Ask yourself why you are using the product. Is it to replace milk in a recipe or add thickness in a smoothie? Once you know why you need it and what you're using it for, then go from there to find the best substitute. You can always ask your nutritionist to help read the label and find a product that fits your needs and doesn't sabotage your health.
For example, for smoothies, filtered water with ¼ cup full fat coconut milk from the can is the best way to get in some healthy fat while getting the smooth, creamy texture of a delicious shake. Full fat coconut milk is also a great replacement for dairy milk in recipes. If you're looking for a dairy-free yogurt option, we prefer a coconut cream or almond milk base.
Rather than a soy latte, a good way to drink coffee would be to have it black, with heavy cream (if you can handle dairy), full-fat coconut milk, or unsweetened nut milk. For a healthy coffee creamer, check out this recipe with options for creaminess, sweetness, or additional flavor… depending on how you take your java.
Learn more: Signs of A Dairy Intolerance (with plenty of ingredient swap options!) and Coffee Creamer Alternatives
Recap On Soy Consumption
Research suggests most soy health benefits and risk factors are mixed. At the end of the day, paying attention to how YOU feel when you eat soy is the most important part.
If you decide your body can tolerate whole soy foods and CAN be part of your healthy nutrition plan, we recommend you stick to the whole food varieties and avoid the processed soy products.
If you struggle with infertility, thyroid function, digestive issues, and hormonal imbalances, we recommend avoiding or using fermented soy foods sparingly. When you eat a whole, real food meal plan in balance, there are still plenty of delicious food options without the risk of developing any health concerns that soy foods might be associated with.
For more information about on soy intake and hormones, check out these resources:
READ: Understanding Estrogen Dominance
READ: Signs of Estrogen Dominance: What It Means & How To Fix It
LISTEN: Estrogeneration – How Estrogenics Are Making You Fat, Sick and Infertile
NutriKey Products Mentioned:
NutriKey Wellness Whey Protein in Vanilla or Chocolate - from grass-fed and rBGH-Free (hormone free) cows, Gluten-Free, GMO-Free and mixes well in just water.
NutriKey Paleo Protein in Vanilla or Chocolate - a great-tasting beef protein powder rich in essential amino acids and contain absolutely no lactose/dairy and minimal fat.
The NutriKey Store also carries quality brands of PurePea Vanila Protein, Pea Protein Isolate Unflavored, PurePaleo Protein Unflavored, and an Egg White Unflavored Protein - you've got options!
