Buzz
Among the wide variety of plant-based milk options available, soy milk is a constant presence on supermarket shelves. But is it actually a healthy choice when compared to cow's milk, or does it fall short? How does its nutritional profile measure up? Are there potential health risks linked to soy consumption? Let's explore the essentials of soy milk, its health benefits, and more.
What Exactly Is Soy Milk?
Soy milk was one of the earliest plant-based milk alternatives to make its way into the mainstream, starting in 1996. Though plant-based milks took some time to gain popularity, they've now become incredibly mainstream. Today, there are countless non-dairy milk options, including oat, almond, cashew, rice, and soy, along with niche varieties like pistachio, walnut, hazelnut, and even sesame seed milk.
Soy milk is created by blending water with soaked soybeans, followed by straining the mixture to remove any solids. This milk alternative can be fortified with nutrients such as calcium and vitamin D to closely mimic the nutritional profile of cow's milk. It can also be sweetened, usually with cane sugar, or flavored with varieties like chocolate, vanilla, strawberry, and more.
Some brands may include additives like stabilizers and thickeners to enhance the texture and consistency of soy milk, making it resemble the cow's milk many of us grew up drinking. Hint: You'll often find the word 'gum' in the names of these ingredients on food labels.
Towfiqu Ahamed/Getty ImagesSoy Milk Nutritional Value
People choose dairy alternatives like soy milk for a variety of reasons, whether due to lactose intolerance, following a plant-based lifestyle, or simply preferring to stock up on shelf-stable milk options.
Soy milk provides a wealth of essential vitamins and minerals, even without fortification. Here's a breakdown of what one cup of soy milk contains.
- Water - 220 grams
- Calories - 105 kcal
- Protein - 6.34 grams (12.68% of the recommended daily value or DV)
- Fat - 9 grams
- Carbohydrates - 12 grams
- Fiber - 0.488 grams (1.74% DV)
- Sugars - 8.91 grams
- Calcium - 300 milligrams (23.08% DV)
- Iron - 1.02 milligrams (5.67% DV)
- Magnesium - 36.6 milligrams (8.71% DV)
- Potassium - 298 milligrams (6.34% DV)
- Sodium - 115 milligrams
- Zinc - 0.634 milligrams (5.76% DV)
Health Benefits of Soy Milk
In general, soy milk is a healthy choice and is the most nutritionally comparable to cow's milk (though there are a few important nutritional differences between them, which we will discuss). Here are some of the key health benefits of soy milk.
Boosts Immunity
Soybeans, and by extension soy milk, are rich in plant compounds, particularly isoflavones and saponins. One notable isoflavone in soy milk is genistein, which has been shown to fight cancer cells in the body by interfering with their growth and reproduction through various therapeutic mechanisms.
The plant compounds in soy, including genistein, also serve as powerful antioxidants with anti-inflammatory effects. This enhances the immune system, helping the body defend against both short-term and chronic illnesses. Additionally, soy milk contains significant amounts of vitamin A and zinc, which provide similar benefits.
Increases Energy
Soy, and consequently soy milk, is among the few plant-based proteins that include all nine essential amino acids, making it a complete protein. This protein not only supports the maintenance and growth of healthy tissues but also promotes sustained energy levels throughout the day.
Depending on how the soy milk is fortified, it may also include B vitamins like riboflavin, B6, B12, and folate, which further support healthy growth, development, metabolism, and energy. Notably, a randomized controlled trial found that older men who combined resistance training with drinking soy milk saw improved performance, body composition, and muscle growth and maintenance.
Supports Heart Health
This drink contributes to heart health from several perspectives. It has a low level of saturated fat, unlike whole dairy, which can elevate cholesterol levels. In contrast, it contains unsaturated fats like omega-3 fatty acids, which help maintain healthy cholesterol. Additionally, soy milk is rich in potassium, which aids in regulating heart rhythm and blood pressure, while vitamin K supports proper blood clotting.
Studies confirm these benefits, with one review showing that the isoflavones in soy milk may reduce heart disease risk. Another found that soy milk acts as a cardioprotective agent by tackling various cardiovascular risk factors. A 2021 meta-analysis revealed that soy consumption was associated with lower blood pressure in adults, while a cohort study that year linked soy consumption four times a week or more with a reduced risk of death from heart attacks.
Protects Gut Health
For those who are lactose intolerant or sensitive to dairy, soy milk offers a perfect alternative since it is naturally free of lactose. A study from 2020 found that soy milk helps reduce systemic and gut inflammation while improving the gut microbiome's health thanks to its fiber content. The gut microbiome is vital not only for digestive health but for overall body well-being as well.
Alleviates Menopause and PMS Symptoms
Soy milk contains plant compounds, such as isoflavones and genistein, which are known as phytoestrogens. These compounds imitate estrogen in the body and can provide relief from common menopause symptoms. A meta-analysis of 15 studies found that phytoestrogens could reduce the occurrence of hot flashes.
Research indicates that soy can help alleviate premenstrual syndrome (PMS) symptoms due to its impact on estrogen levels in the body. A seven-cycle, double-blind, placebo-controlled study of 23 women aged 18-35 showed that isolated soy protein (ISP) reduced the intensity of PMS symptoms. While further research is needed to conclusively establish soy protein, including soy milk rich in protein, as a PMS treatment, the results suggest it’s beneficial.
Supports Bone Health
Fortified soy milk often includes added vitamin D and calcium, both of which, along with vitamin K, are vital for the development and preservation of strong bones. Additionally, the isoflavones in soy milk have been shown to combat bone loss, with a 2022 study in the Journal of Clinical Medicine linking soy isoflavones to a reduction in bone loss in postmenopausal women.
Helps Lower Cholesterol
Soy consists of polyunsaturated fatty acids, lecithin, and stigmasterol, which have all been proven to lower total cholesterol levels. These compounds are also associated with reduced low-density lipoprotein (LDL) cholesterol, which may aid in managing or preventing diabetes. The fermentation process further enhances the nutritional quality of soy, improving its digestibility and the absorption of soy protein.
Promotes Brain Health
In addition to its core nutrients, soy milk provides magnesium and iron. Magnesium supports better sleep and the functioning of the nervous system, while iron is crucial for the formation of healthy red blood cells—both important for optimal brain function. Additionally, daidzein, another isoflavone present in soy milk, has been shown to offer neuroprotective benefits, contributing to overall brain health.
The isoflavones in soy milk mimic estrogen, influencing neurotransmitter production, including serotonin and dopamine. This means they play a role in regulating mood. Their antioxidant and anti-inflammatory effects also help combat oxidative stress, which is often linked to mental health conditions.
Soy Milk vs. Whole Milk
Both soy milk and whole milk are popular choices for beverages, whether you’re adding them to coffee or pouring them over cereal. Despite their common use, they differ significantly in taste and nutrition (though soy milk provides many of the same health benefits as cow's milk).
Soy milk, derived from soybeans and free from lactose, is commonly enriched with nutrients like calcium and vitamin D, which are naturally present in cow's milk. It still retains many of the same essential amino acids while being lower in saturated fats compared to the richer whole milk.
Whole milk, especially cow’s milk, contains more fat, giving it a thicker, creamier texture that some prefer, particularly in coffee and tea. However, it also has higher cholesterol content, which may be a concern for those managing cholesterol levels or focusing on heart health.
For those who are lactose-intolerant or seeking a milk alternative with less saturated fat, soy milk is often the go-to choice. On the other hand, cow’s milk, particularly whole milk, is packed with more nutrients that support bone health. However, its higher fat content means it should be consumed in moderation.
Is Soy Safe for Everyone?
You may have come across concerns about soy and its potential impact on thyroid health or its association with certain types of cancer. Fortunately, extensive research on soy safety has debunked these fears, with current evidence refuting such claims.
A systematic review from 2019, published in Scientific Reports, found no connection between soy consumption and thyroid function, although a slight correlation between high soy intake and marginally increased thyroid-stimulating hormone (TSH) was noted. The study concluded that these lab findings were likely to have minimal, if any, clinical importance.
Regarding cancer, numerous studies have shown no link between soy, its isoflavones, and cancers commonly associated with it, such as breast and prostate cancer. In fact, two meta-analyses discovered that higher intake of soy isoflavones was correlated with a lower risk of breast cancer in women.
An additional study published in Cancer found that soy isoflavones, when consumed by women undergoing breast cancer treatment, were associated with a reduced risk of mortality. Concerning prostate cancer, a systematic review in Nutrients showed that soy consumption lowered prostate cancer risk. Furthermore, another review concluded that neither soy nor soy isoflavone intake had any impact on male reproductive hormones, debunking another common myth.
How to Pick a Healthy Soy Milk Product
Before offering soy milk to your family, it’s important to keep a few considerations in mind. Firstly, avoid serving it to anyone with a soy allergy, as soy is a common allergen. Secondly, try to choose unsweetened varieties to limit your intake of added sugars. Lastly, opt for a brand that fortifies its soy milk with essential nutrients like vitamins and minerals, ensuring maximum nutritional value in every serving.
Another option is making soy milk at home using a blender and cheesecloth, or a nut milk maker such as Almond Cow. This method gives you full control over any unwanted additives or mysterious ingredients, resulting in a nutritious, unfortified product.
Although soy milk might cost more than cow's milk, the incredible health benefits it offers make it well worth the price. Consuming one to two servings a few times a week is a great way to enjoy the full benefits of soy milk.
