How Healthy is Soy Milk?

1 comment by Stacy Facko


Soy milk has long been a popular non-dairy alternative, praised by many for its nutritional benefits and its suitability for vegan and lactose-intolerant individuals. But is drinking soy milk every day actually good for you? Opinions have evolved over the years, and like most foods, soy milk comes with both benefits and potential downsides. Here, we break down the effects of consuming soy milk, giving you everything you need to know to decide if it’s the right choice for your lifestyle.

1. It Could Increase Your Risk of Chronic Disease

One of the downsides of soy milk lies in the added sugars often found in conventional options, especially flavored varieties like vanilla soy milk. Some brands can have up to 14 grams of added sugar per serving. Consuming too much added sugar can increase your risk of chronic diseases such as heart disease, kidney disease, and even certain cancers, according to the American Heart Association. Research published in Circulation also highlights that high sugar intake is strongly associated with an increased risk of cardiovascular disease (Johnson et al., 2009).

2. It Can Hinder Nutrient Absorption

Soy milk contains natural components known as "anti-nutrients," including phytic acid, that can interfere with the absorption of certain minerals like iron, calcium, and zinc. While soy milk contains 23% of the daily calcium recommendation in one serving, the bioavailability of this calcium is not as high as in cow’s milk, and excess calcium is linked to many diseases (Martini et al., 2020)

That said, moderate consumption of soy milk won’t likely cause deficiencies, and its nutrient-rich profile may offset these anti-nutrients’ effects.

3. It Could Affect Thyroid Function

Soy isoflavones, compounds found in soy-based foods, have been linked to potential thyroid issues in people with borderline abnormal thyroid levels (Messina & Redmond, 2006). If you have a thyroid condition or are on thyroid medications, consult your doctor before drinking soy milk daily.

4. It May Lower Inflammation

On the upside, soy isoflavones have been shown to reduce inflammation. Chronic inflammation is linked to various diseases, such as heart disease, cancer, and arthritis. Research, including a 2015 study in the Nutrition and Dietetics Journal of Dietitians Australia, shows that drinking soy milk can significantly lower certain inflammation markers. For those looking to manage inflammation, soy milk could be a helpful addition to their diet.

5. It Could Improve Your Heart Health

Soy milk is also heart-healthy. Studies have shown that consuming 25 grams of soy protein daily can help reduce LDL (“bad”) cholesterol and overall cholesterol levels. Soy protein contains specific compounds, like the 7S globulin fraction, which contribute to this effect.

If you’re not a fan of the taste of plain soy milk, you can still reap similar benefits with flavored soy milk, though you should monitor your added sugar intake.

6. It Could Help Improve Muscle Mass

Thanks to its protein content—7 grams per cup—soy milk is a strong contender for those looking to increase their protein intake. Unlike other dairy-free alternatives like almond or coconut milk, soy milk provides a substantial protein boost, making it a fantastic option for athletes or those focusing on strength training.

Adding one to two cups of soy milk a day to your diet can help you meet your protein goals, especially when paired with resistance training.

7. It Could Lower Your Risk of Breast Cancer

In earlier years, there was concern that soy might increase the risk of breast cancer due to its isoflavones, which act as weak estrogen mimics. However, more recent studies have shown the opposite.

One large-scale 2015 study analyzed over 23,000 individuals assigned female at birth (AFAB) and found that those who consumed soy were 69% less likely to develop breast cancer. This has led researchers to conclude that soy may offer protective benefits, particularly for premenopausal individuals.

8. You May Sleep Better

Soy milk may even help improve sleep. Soybeans are a good source of tryptophan, an amino acid that helps produce melatonin, also known as the sleep hormone. Additionally, soy isoflavones mimic estrogen’s effects, which can positively impact sleep duration and quality.

A 2015 study in the Nutrition Journal found that people who consumed two or more servings of soy foods daily experienced significant improvements in both sleep duration and quality.

What About GMOs?

Most soybeans grown in the United States are genetically modified, but the World Health Organization considers GMO foods safe to eat. If you prefer to avoid GMOs, you can look for soy milk labeled with the Non-GMO Project seal, which ensures the use of non-modified soybeans in production.

Should You Add Soy Milk to Your Diet?

Soy milk can be a healthy addition to many diets when consumed in moderation, provided you choose unsweetened options and remain mindful of your specific health needs. Here’s a quick summary of the pros and cons:

Pros of Drinking Soy Milk Daily

  • May reduce cholesterol, compared to ultra-pasteurized, factory-farmed dairy, supporting heart health
  • May be linked to lower inflammation, again compared to industrial cow dairy
  • Can improve sleep quality

Cons of Drinking Soy Milk Daily

  • Added sugars in flavored varieties can increase the risk of chronic diseases
  • Anti-nutrients may reduce mineral absorption
  • Could impact those with thyroid issues
  • Most brands use GMO soybeans (although non-GMO options exist)
  • Pesticides and glyphosate are real concerns

Although, in general it appears that the benefits of soy milk for some people may outweigh the risks, most are better off avoiding it altogether, not only due to the estrogenic nature of isoflavones but also the cross-contamination of which soy is a large recipient. Always consult a good healthcare professional or naturopath if you’re unsure about adding it to your daily routine. 

 

 

References

  1. Messina, M. (2016). Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature. Nutrients, 8(12), 754. https://doi.org/10.3390/nu8120754
  • This study highlights the cholesterol-lowering properties of soy and its impact on heart health.
  1. Rebello, C. J., Greenway, F. L., & Finley, J. W. (2014). A review of the nutritional value of soy foods. Journal of Nutrition, 144(12), 2133S–2143S. https://doi.org/10.3945/jn.114.194605
  • This research discusses the high protein content in soy milk and its effects on muscle development.
  1. Bahreini, A., Noor, M. M., Azizi, M., & Jamil, S. F. (2019). Effects of Soy Milk Consumption on Thyroid Hormonal Activity and Health. Clinical Nutrition Experimental, 24, 72-78. https://doi.org/10.1016/j.yclnex.2019.07.001
  • This article examines the potential impact of soy on thyroid health and related concerns.

1 comment


  • Bruce McMahon

    Obviously one of those veg people. How about the estrogen. How about how it is affected in the process of making it. Sounds like you put in a plug for GMO’S. Really? Fake food. One of the most damaging for the overall health of society. Got to be one of the dumbest articles I have read in a long time. Hope you are a better doctor than an author. Probably just wishful thinking.


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