If you're lactose intolerant, concerned about the environment or you just aren't into the taste of cow's milk, you can reach for soy milk as a comparable alternative. Made from soybeans or soy flour, this pick is one of the more popular milk alternatives on the market.
It generally has a longer shelf life than dairy milk and some types of packaged soy milk can be stored at room temperature for months, which helps eliminate waste caused by food spoilage. Soy milk also has a number of nutritional advantages, although some varieties of soy milk come loaded with sugar, which can pose a health risk.
Consider these pros and cons of soy milk before you swap your go-to glass.
The Health Benefits of Soy Milk
1. Soy Milk Packs Protein
Try including soy milk in your diet as a source of protein. Soy protein can help lower levels of LDL, or bad cholesterol, according to the National Center for Complementary and Integrative Health. Each cup of unsweetened, plain soy milk provides 7 grams of protein, according to the USDA. For reference, a glass of two-percent dairy milk contains 8 grams of protein.
Unlike most plant-based proteins — which contain some, but not all, of the amino acids you need in your diet — soy contains all nine essential amino acids. Your body assembles these amino acids into new proteins, including antibodies essential for immune system function, structural proteins that hold your tissues together and enzymes that help your cells produce energy.
Are You Getting Enough Protein?
2. It Doesn’t Increase Risk of Breast Cancer
It was once thought that soy foods — because of their isoflavones, a phytoestrogen — can increase your risk of breast cancer. This belief has since been refuted, according to the American Cancer Society.
A February 2020 study published in the International Journal of Epidemiology adds to this consensus finding that drinking soy milk is not linked to an increased risk of breast cancer and may actually help protect against it.
3. It's Healthy for Men, Too
Soy-based foods like tofu and soy milk contain isoflavones that perform functions in the human body similar to the hormone estrogen. Some men may avoid soy foods out of worry that too many phytoestrogens can have a negative effect on the hormone balance of the male body.
However, isoflavones in soy do not increase estrogen levels in men and eating soy does not seem to affect testosterone levels, according to a May 2010 analysis in Fertility and Sterility.
And a bonus: Eating or drinking soy foods, like soy milk, is associated with a reduced risk of prostate cancer, according to Oregon State University.
4. It Contains Calcium and Iron
Drinking soy milk also helps boost your calcium and iron intake. Your body relies on the calcium from your diet to maintain dense and strong bone tissue. Without it, your body draws on your bones as a source of calcium, which can reduce your bone density over time.
One cup of unsweetened plain soy milk boasts 301 milligrams of calcium. This contributes close to 30 percent toward your recommended daily calcium intake of 1,000 to 1,200 milligrams, according to the National Institutes of Health.
The iron in soy milk helps your red blood vessels function properly, helping ensure that all the tissues throughout your body get the oxygen they need. Each serving of soy milk provides 1.1 milligrams of iron, contributing to the recommended daily intake of 8 milligrams for men and 18 milligrams for women.
5. It Boasts Riboflavin and Vitamin B12
Soy milk also helps you get more B-complex vitamins and serves as an especially rich source of riboflavin (vitamin B2) and vitamin B12. Getting enough vitamin B12 in your diet helps your cells produce DNA, aids in red blood cell function and also keeps your nerves healthy.
One cup of soy milk provides 2.7 micrograms of vitamin B12, which is more than the 2.4 micrograms you need each day. The riboflavin in soy milk helps your cells produce energy and shields your DNA from damage. Drinking one cup of soy milk boosts your riboflavin by 0.5 milligrams — close to 50 percent of the recommended daily intake.
6. Soy Milk Is Vegan
Vegans can eat soy and soy milk is a good alternative for anyone who chooses to avoid dairy products for health or other reasons.
Soy provides protein — a significant benefit to vegans or anyone following a diet low in animal proteins. Soy does not contain cholesterol and is low in fat. Products with soy also provide important nutrients such as calcium, vitamin D and vitamin A.
You can use soy milk in any recipe as a substitute for regular milk, and you can simply drink a glass of it. You will likely notice some flavor differences, but most people adjust to the taste of soy milk easily.
You Can Also Buy Shelf-Stable Soy Milk
Unlike cow’s milk, you can find some soy milks in the non-refrigerated section of your grocery store. Aseptic packaging is used and you’ll find them with other shelf-stable milk alternatives, typically in the “natural foods” section of your supermarket. The aseptic packaging has a 12-month shelf life and once it’s opened, it must be refrigerated and consumed within a week.
The Disadvantages of Soy Milk
1. Soy Allergy
Don't shy away from including soy milk in your diet out of fear of soy — as noted above, soy foods are safe for most people. The exception is those who have soy allergies.
According to Food Allergy Research & Education (FARE), soy is one of the top nine food allergies. It can be a difficult ingredient to avoid because soy is commonly used in many processed foods such as soy lecithin and soybean oil. If you're allergic to soy and looking for another non-dairy milk alternative, consider trying oat milk, coconut milk, almond milk or flax milk.
2. Added Sugars
Some types of soy milk do have a major nutritional disadvantage because of their added sugar content. Added sugars boost your calories without offering nutritional value, and can increase your risk of heart disease and type 2 diabetes.
Select unsweetened soy milk to minimize added sugar — the unsweetened stuff contains just 1 gram of naturally occurring sugars per cup and no added sugar. Chocolate- and vanilla-flavored soy milks, in contrast, contain around 20 and 7 grams of added sugar per serving, respectively.
Does Soy Milk Cause Gout?
Uric acid is a waste product that forms from the degradation of genetic material such as DNA and RNA. Uric acid is benign at normal levels but if excessive levels of uric acid build up and form needle-like crystals in the joints, it can cause a painful inflammatory arthritic condition known as gout. This is most likely to occur in the big toe, knee or ankle joints, per the U.S. National Library of Medicine.
Purines are thought to increase uric acid levels in the blood. But soy milk is classified as a food very low in purines and therefore OK to eat on a gout diet, per a 2014 study in Biological & Pharmaceutical Bulletin.
What's more, dairy milk is good for gout, too — it's associated with a lower risk of the disease, according to a 2004 study in The New England Journal of Medicine.
- USDA National Nutrient Database: SILK Unsweetened, Soymilk
- National Center for Complementary and Integrative Health: Soy
- National Institutes of Health, Office of Dietary Supplements: Calcium
- National Institutes of Health, Office of Dietary Supplements: Iron
- National Institutes of Health, Office of Dietary Supplements: Vitamin B12
- USDA National Nutrient Database: Vitasoy, Soy Drink, Chocolate
- USDA National Nutrient Database: Vitasoy Light Vanilla Soymilk
- American Cancer Society: "Soy and Cancer Risk: Our Expert’s Advice"
- International Journal of Epidemiology: "Dairy, Soy, and Risk of Breast Cancer: Those Confounded Milks"
- Soyfoods Association of North America: "Soymilk"
- Food Allergy Research & Education (FARE): "Food Allergy Essentials, Common Allergies"