Is Soy Milk Good for You?

Medically reviewed by Aviv Joshua, MS

Soy, a versatile and nutrition-packed legume, has become a staple in the world of plant-based diets and alternative milk options. Soy milk, in particular, is a well-known plant-based beverage known for its high nutritional profile. Rich in protein and low in calories, soy milk may offer an array of benefits, such as aiding in the reduction of high blood pressure, lowering cholesterol, combating inflammation, preventing hormone-related cancers, and much more.

However, while soy milk is a nourishing choice for many, it may not be suitable for everyone. In this article, we will explore the pros and cons of soy milk to help you make an informed decision that aligns with your dietary needs and preferences.

barleyman / Getty Images
barleyman / Getty Images

How Is Soy Milk Made?

Commercial soy milk is produced by grinding and blending soaked soybeans with water, followed by heat treatment and homogenization, resulting in a commercial-scale production of soy milk.

To make soy milk at home, you begin with either regular or germinated soybeans. The process involves cleaning, soaking, and mixing the soybeans with water (at a 9-to-1 ratio, meaning 9 parts water for 1 part soybeans).

There are two methods for making soy milk: One is similar to using a regular blender, and the other employs a specialized soy milk maker. In both methods, the soaked soybeans and water are processed to create a thick soy slurry.

Here are the steps on how to make soy milk:

  • Clean and soak soybeans.

  • Mix soaked soybeans with water.

  • Blend the mixture using a regular blender or a soy milk maker.

  • Strain the blended mixture to separate solids and obtain liquid soy milk.

Soy Milk Nutrition

Soy milk has a wide range of nutritional benefits, some of which include:

  • Source of high-quality plant-based protein, providing essential amino acids for muscle and tissue health

  • Naturally low in saturated fats and cholesterol, making it heart-healthy

  • Fortified with vitamins and minerals, such as calcium and vitamin D

  • Good source of potassium, which supports heart and muscle function

  • Naturally lactose-free

Additionally, soy milk contains compounds called isoflavones, which are phytoestrogens that may offer potential health benefits, such as reducing the risk of certain cancers.

According to the U.S. Department of Agriculture (USDA), 1 cup of soy milk contains the following nutrients:

  • Calories: 105 kilocalories (kcal)

  • Protein: 6.34 grams (g)

  • Fat: 3.5 g

  • Carbohydrates: 12 g

  • Total dietary fiber: 0.488 g

  • Total sugars: 8.91 g

  • Calcium: 300 milligrams (mg)

  • Iron: 1.02 mg

  • Magnesium 36.6 mg

  • Potassium: 298 mg

  • Sodium: 115 mg

Potential Soy Milk Health Benefits

The array of potential health benefits associated with the consumption of soy milk, from heart health to bone strength, is as follows.

May Improve Cholesterol

Soy milk has been linked to potential improvements in cholesterol levels due to its high content of soy protein, which contains beneficial compounds known as isoflavones. These isoflavones, particularly genistein, have been shown to have a cholesterol-lowering effect by reducing low-density lipoprotein (LDL) cholesterol ("bad" cholesterol) while increasing high-density lipoprotein (HDL) cholesterol ("good" cholesterol).

Additionally, soy milk is naturally low in saturated fats, further contributing to its potential to promote a healthier lipid profile when incorporated into a balanced diet.

May Reduce High Blood Pressure

A 2021 systematic review and meta-analysis looked at how soy can affect blood pressure. Soy, it appears, may reduce blood pressure due to its isoflavones. Isoflavones help enhance the functioning of blood vessels, promoting relaxation and ultimately contributing to lowering blood pressure.

May Lower Inflammation

Isoflavones in soy, such as genistein, also act as antioxidants by scavenging free radicals (molecules that can damage DNA and cause cancer) and reducing inflammation triggers. Isoflavones in soy milk play a vital role in protecting your body from inflammation and its associated health risks.

May Support Weight Maintenance

Soy may support weight maintenance through several mechanisms. First, it's a rich source of protein, which can promote a feeling of fullness and reduce overall calorie intake and aid in weight control. Consuming soy protein can also improve insulin resistance, which is when the body does not respond to insulin as it should.

Additionally, soy foods often replace less healthy options in the diet, reducing the consumption of high-calorie, high-fat foods. The isoflavones in soy may play a role in regulating body weight by influencing hormones related to appetite and fat storage

Improved Heart Health

Research suggests that including soy-rich foods, including tofu and soy milk, in one's diet may offer unexpected benefits for heart health. Isoflavones have been linked to a reduced risk of heart disease, particularly among younger women and postmenopausal women not taking hormones.

One study, which examined data from 200,000 individuals, revealed that consuming at least one serving of tofu a week was associated with an 18% lower risk of heart disease compared to those who rarely ate tofu.

While these findings are promising, experts emphasize that overall diet quality, exercise, family history, and lifestyle habits also play crucial roles in heart health, making isoflavone and soy-rich foods a healthy component of a balanced diet rather than a magic bullet for preventing heart disease.

Reduced Menopause Symptoms

Soy may help alleviate menopausal symptoms due to its rich content of isoflavones, which are natural plant compounds with estrogen-like properties. These isoflavones, particularly genistein and daidzein, can bind to estrogen receptors in the body.

This may help balance hormonal fluctuations during menopause and prevent menopausal symptoms, including:

  • Fatigue

  • Depression and mood symptoms

  • Hot flashes

  • Bone loss

Potential Soy Milk Downsides

With the exception of individuals with soy allergies, soy is generally regarded as a safe dietary choice. In addition, while research has shown the safety of short-term use of soy protein supplements and isoflavone-rich soy extracts, the long-term safety remains uncertain.

Some potential soy milk downsides may include:

  • Digestive side effects like constipation and diarrhea

  • An impact to thyroid function in individuals with iodine deficiency

In addition, current evidence suggests that soy foods are safe for women with a history of breast cancer or those at risk. Still, the safety of soy isoflavone supplements for this group remains uncertain.

Consuming too much soy during pregnancy may pose risks due to potential harm to the fetus from soy's estrogen-like compounds. The safety of higher soy consumption while breastfeeding still needs to be understood. Talk to your healthcare provider to see if soy milk is safe during pregnancy and breastfeeding.

Is Soy Milk Bad for You?

While soy milk is generally considered safe and nutritious, there are some individuals who may want to limit or avoid it, including those with the following health issues:

  • Soy allergy: Soy allergies can cause a range of symptoms, from mild hives to severe anaphylaxis.

  • Thyroid issues: Some studies suggest that excessive consumption of soy products, like soy milk, might affect thyroid function, particularly in individuals with iodine deficiency or preexisting thyroid disorders.

  • Infants: While soy-based infant formulas are available and appropriate for some babies, it's important to consult a pediatrician or other healthcare provider before introducing soy-based products to an infant's diet. They can guide whether soy formula suits your child's specific needs.

If you have any concerns, reach out to your healthcare provider or a registered dietitian to determine the most appropriate dietary choices for your individual needs.

Summary

Soy milk is a versatile and nutritious plant-based option with numerous health benefits, including potential improvements in cholesterol levels, reduced risk of high blood pressure, inflammation control, support for weight management, and even relief from menopausal symptoms. However, while soy milk is generally safe, it might not suit everyone. Individuals with soy allergies should avoid soy products. Those with thyroid issues or parents of infants should exercise caution in soy use.

Anyone with specific health concerns should consult a healthcare provider or registered dietitian for personalized dietary recommendations. Overall, soy milk can be a valuable addition to a balanced diet, but making informed choices based on individual health needs and preferences is essential.

Read the original article on Verywell Health.