Can Plant Milks Really Take the Place of Cow’s Milk?

Have you ever thought about the differences between the milk that comes from cows and the other “milks”, the ones derived from plants?  When you think about it, their disparities are many.  For a start, cow’s milk is produced by an animal for the purpose of providing the energy and nutrients needed for a calf to grow up healthy and strong.  But plants have no need for milk to nurture their young offspring.  Let’s face it, plants and animals have very few similarities.

Plant milks have been around long enough now for us to know that they can substitute for cow’s milk in many areas of our lives.  They perform the same role as cow’s milk in dishes like soups, stews and sauces. They make great chocolate milk.  They can be used in place of cow’s milk when baking, providing a needed liquid ingredient that looks and acts like cow’s milk.  Plant-sourced milks even brown up nicely to create enticing baked desserts.

(Side Note; Among all the plant milks, soy milk is especially good for baking. It is the one most similar to cow’s milk in its fat and protein content making its structure very comparable to that of cow’s milk.  In addition, soy milk doesn’t have much flavour of its own so it doesn’t appreciably alter the taste of the cakes, cookies or breads that it becomes a part of.)

 But what about our personal health?  The dairy industry has extolled the nutritional wonders of cow’s milk for decades.  Are plant-sourced milks up to taking over this much-revered role?

In 2023 the International Journal of Disease Reversal and Prevention published the results of a new study examining the ability of milks sourced from plants to perform a similar role in our health as does milk sourced from cows.  In this research, cow’s milk was compared to almond, soy, oat, coconut, rice, pea, cashew, and other plant-based milks as data were available.  (1)

 

The conclusion of this study was that

 there is no health rationale

for recommending the consumption of cow’s milk

over plant-based milk

 

Let’s take a close look into the similarities and differences amongst some of the most popular plant-sourced milks and cow’s milk and discover why plant milks should indeed take the place of milk from a cow. (1)

 

Nutrition Facts for Soy milk, Oat milk and Cow’s Milk

 

SOY MILK (2)

SERVING SIZE 1 CUP (240 GM)

CALORIES – 80

Total Fat                              4 gm

Saturated Fat      0.5 gm

Trans Fat              0 gm

Cholesterol         0 mg

Sodium                                90 mg

Total Carbohydrate           4.25 gm

Dietary Fiber       1.2 gm

Total Sugars        1 gm

Protein                                7 gm

Vitamin D                           3 mcg  (added)

Calcium                               302 mg  (added)

Potassium                           292 mg

Phosphorus                        78 mg

Iron                                      1.1 mg

 

 

 

OAT MILK (2)

SERVING SIZE 1 CUP (240 GM)

CALORIES  – 116

Total Fat                              4.8 gm

Saturated Fat      0.5 gm

Trans Fat              0 gm

Cholesterol          0 gm

Sodium                                111 mg

Total Carbohydrate           6 gm

Dietary Fiber       1 gm

Total Sugars        5 gm

Protein                                2.1 gm

Vitamin D                           3 mcg  (added)

Calcium                               300 mg  (added)

Potassium                           435 mg

Phosphorus                        250 mg

Iron                                      2 mg

 

 

 

COW’S MILK- WHOLE MILK (2)

SERVING SIZE 1 CUP (240 GM)

CALORIES – 75

Total Fat                              8 gm

Saturated Fat      5 gm

Trans Fat              Variable

Cholesterol          24 mg

Sodium                                105.6 mg

Total carbohydrate           12 gm

Dietary Fiber       0 gm

Total sugars         12 gm

Protein                                8 gm

Vitamin D                           2.5 mcg  (added)

Calcium                              300 mg  (added)

Potassium                           297 mg

Phosphorus                        232 mg

Iron                                      <1 mg

 

 

Comparisons Between Milks

 Fat and Cholesterol (1,2,3): 

 Plant milks contain lower amounts of fat than cow’s whole milk and are especially low in saturated fat.

Cow’s milk contains cholesterol and trans-fats; plant milks do not.

• Did you know that dairy is now the primary source of saturated fat in our diet? Saturated fat raises cholesterol including LDL-C (Low Density Lipoprotein Cholesterol, aka “bad cholesterol”) which causes atherosclerosis (dangerous building up of plaques within blood vessels) and is significantly linked with increased risk of developing heart disease (heart attacks and strokes). (4,5)
• Cow’s milk has double the total fat content of soy milk, oat milk, rice milk and almond milk. Coconut milks are generally higher in total fat than cow’s milk.
• Cow’s milk has about five times the saturated fat of soy milk and oat milk. Almond and rice milk are also lower in saturated fat than cow’s milk, though not as low as soy milk and oat milk.  Some coconut milks are extremely high in saturated fat with levels up to six times higher than those found in cow’s milk.
• Higher consumption of cow’s milk is linked to greater risk of death from heart disease. Results from a 2024 study show that replacing cow’s milk with soy milk (including sweetened soy milk) has health advantages over cow’s milk, namely lower blood pressure, less inflammation and healthier lipid profiles (reductions in LDL-C).  No adverse health effects were observed from replacing cow’s milk with plant milks.  (6)
• In addition, replacing dairy fat with either high-quality carbohydrates (such as whole grains) or with fats derived from vegetables is associated with a significant reduction in the risk of heart disease. (7)

 

Carbohydrates – Sugars and Fiber (1,3): 

 Soy milk contains the least amounts of sugars among milks, with soy milk at 1 mg, oat milk at 5 mg and cow’s milk the highest at 12 mg.

• The dominant sugar in cow’s milk is lactose. Lactose requires an enzyme called lactase to break it down.  Lactase is present in babies and young children to ensure that the lactose in their milk is properly metabolized so that early growth is successful.  However, as a person ages, lactase is no longer needed and about 75% of the world’s population loses the ability to produce lactase by the time they are in their late teens.  This means that the majority of people on our planet have lactose intolerance, a condition in which ingesting milk causes upset stomach, diarrhea and gas.  Europeans and their descendants are the exception in that they often retain their ability to produce lactase (28).
• The sugars found in plant milks do not contribute to digestive symptoms.

 

Soy and oat milk both contain dietary fiber while cow’s milk does not.

• Fiber is a nutrient which is very low in the diets of many people. Fiber has multiple benefits.  Ensuring the formation of a soft stool that easily makes its way through the digestive system and prevents constipation is one.  Prevention of some cancers is another.  But perhaps its most important role is to support a healthy microbiome in the gut which we now know is critical for our own health.
• Fiber feeds the “good” bacteria in the large intestine so that it flourishes, preventing overgrowth of “bad” bacteria. When these “good” bacteria consume fiber in the large intestine, they produce short-chain fatty acids that have far-reaching health effects including the reduction of inflammation and the prevention of several cancers including colon, breast, esophageal, lung and liver cancer.  (8)
• A recent epidemiological study shows a clear association between the consumption of fiber and a reduction in early death from all causes. Those eating between 20 and 30 grams of fiber daily have a 10 to 20% reduction in death from any cause.  (9)
• A study of young women revealed that eating a diet high in fiber resulted in a 25% lower risk of developing cancer later in life. (10)
• The American Institute for Cancer Research (AICR) recommends eating at least 30 gm of fiber daily to reduce the risk of cancer. Specifically, for every 10-gram serving of fiber a day there is a 7% decrease in the risk of colorectal cancer.  (11)

 

 Protein (1): 

Cow’s milk, soy milk and pea milk are similar in protein content with higher levels than almond, oat, rice, or coconut milk.

• It’s not just the amount of protein in a milk that is important. The types of proteins contained in cow’s milk and plant-sourced milks are different from one another and do not have the same effects on the human body.
• Dairy proteins come in the form of whey and casein. Casein has the unfortunate ability to stimulate cancer cells to start and continue to grow.  This seems to play a role in the increase in breast and prostate cancer linked with the ingestion of cow’s milk.  Casein can also be converted into casomorphine, an addictive molecule.  Casomorphine is important for a calf because it encourages the calf to drink lots of its mother’s milk and thus grow quickly.  There is casomorphine present in human milk as well, though at a much lower concentration.
• The plant-based proteins found in plant milks are associated with lower risks of diabetes, cardiovascular disease and some cancers. (12)
• Recent research is showing that eating soy protein can reduce LDL-C (“bad cholesterol”) and lower the risk of heart disease. Research published in 2022 demonstrated that even small amounts of soy in the diet are associated with a 17% decreased risk of early death and a 14% lower risk of having a cardiovascular event such as a heart attack.  These results were obtained after the researchers controlled for confounding factors such as age, sex, physical activity, healthy diet, smoking, drinking alcohol, blood pressure, blood sugar and lipid levels.  (13)

 

Calcium (1,3): 

Cow’s milk, soy milk and oat milk are similar in their levels of calcium. Dairy milk derives some of its calcium from the grass that a cow eats and the rest from fortification.  Plant milks are usually fortified with similar amounts of calcium. 

• It is interesting to look at the effectiveness of our bodies to absorb calcium from milk. Calcium is  not easy to break down in the gut and, just because calcium is present in a food, it is not necessarily completely absorbed by the body.
• It turns out that calcium is much more easily absorbed when it comes from beans, green leafy vegetables and plant-based milks compared to cow’s milk. For example, dairy-sourced foods, calcium-fortified orange juice, and some tofu have a bioavailability for calcium of about 30%. So, a food label might say that milk contains 300 mg of calcium per cup, but only about 100 mg will be absorbed into the body.
• On the other hand, plant-sourced foods have a higher bioavailability for calcium of about 50 to 60%. The leafy green bok choy, for example, contains about 160mg of calcium per cooked cup and 80 to 96 mg of that calcium will be absorbed, almost as much as that from 1 cup of milk with its lower availability.
• This situation is complicated somewhat by the presence of “anti-nutrients” such as oxalates and phytates. They can bind to calcium and decrease its bioavailability.  Spinach, Swiss chard and beet greens are examples of calcium-binding foods due to their higher oxalate content.  This doesn’t mean that you shouldn’t eat these leafy greens; they are all chock full of other valuable healthy nutrients. Our digestive system can also adapt to the presence of oxalates and phytates when they are eaten regularly to overcome most of the anti-nutrient effect.  (27).
• A diet that encompasses a wide variety of plant-sourced foods will cover all your calcium needs as well as that of other nutrients.

 

 Sodium and Potassium (1): 

Cow’s milk, soy milk and oat milk are similar in their levels of sodium.

 Oat milk is higher in potassium at 435 mg while soy and cow’s milk are similar at about 300 mg. Almond milk and rice milk are lower in potassium.

• Potassium is a mineral that helps to keep blood pressure down.
• Sodium is a mineral that tends to increase blood pressure.
• For human health, the levels of potassium and sodium should be balanced.
• The current intake of sodium in humans is much higher than it should be. This is because our foods of today are often very high in sodium.  We are confronted with many sources of sodium, especially from the increasing variety of ultra-processed foods that are now available.
• Many people are not eating enough potassium-containing foods. The best potassium sources are whole plants including tomato products, raw spinach and beet greens, yams and sweet potatoes, Russet potatoes with the skin, Swiss chard, soybeans, avocado and bananas.

 

Phosphorus (1):

 Soy milk is low in phosphorus while the phosphorus in oat and cow’s milk is about 3 times higher.  Phosphorus is available in a wide variety of foods and deficiencies in humans are rare.

  

Iron:

 Iron levels are higher in plant-based milks than in cow’s milk. 

 Plant-sourced iron is in a non-heme form (compared to the heme form found in animal-sourced foods). Our bodies are better at moderating the absorption of non-heme iron, keeping a balance between an adequate iron level and one which is too high.  This makes non-heme iron a safer way to acquire the iron you need. (14)

 

 Iodine (1):

Iodine is present in cow’s milk due to iodine-fortified feed and contamination from the use of iodine-containing disinfectants for the teats of cows during the milking process.  Iodine levels are quite variable in dairy milk. 

Non-dairy milks contain only very small amounts of iodine. 

• Iodine is an essential component of thyroid hormones. People can acquire iodine from foods like seaweed and some fish.  In Canada and many other countries legislation requires that iodine is added to table salt.  Using iodized salt in the kitchen and on the table will ensure that you’re getting enough iodine.  However, other salts such as sea salt and Himalayan salt are not iodized.  Be sure to check your labels or regularly eat seaweed to ensure that you are getting the iodine your thyroid gland needs. (15)
• Alternatively you can eat seaweed. The recommended daily intake of iodine is around 150 mcg/day for adults.  This can be achieved by eating 2 nori sheets, 1 tablespoon of dulse flakes, one teaspoon of dried arame or 1 tablespoon of seaweed salad. (26)

 

Vitamin D (1):

 Vitamin D levels are similar across the milks. Cow’s milk is usually fortified with vitamin D and most plant milks also have Vitamin D added to them. 

 

Hormones (1):

 Cow’s milk contains hormones such as estrogens (estradiol and estrone) and insulin-like growth factor-1 (IGF-1) while plant milks do not.

• Milk and dairy products now deliver 60 to 80% of the estrogens and other sex steroids consumed by humans.
• These hormones are present in cow’s milk because cows are already pregnant with their next calf while they’re producing milk ostensibly for their present calf. In fact, dairy calves receive very little of their mother’s milk.  Only the colostrum, the very first milk produced, is fed to a new calf.  Colostrum is necessary because it provides antibodies for the protection of the calf from diseases in early life while its immune system is developing.   By the time the calf is three days old it will be ingesting only an artificial “milk replacer”.  (16)
• The milk that the cow gives and that we purchase in our grocery stores contains these hormones.
• Estrogens and IGF-1 are associated with increased risk of certain cancers (breast cancer and prostate cancer), menopause symptoms and reduced fertility.

 

Phytochemicals:

 Dairy milk generally contains very few phytochemicals.

 Plant-sourced milks can contain a wide variety of phytochemicals. 

• Phytochemicals are produced by all plants for protection of the plant’s immune system and against viruses, bacteria, fungi and parasites.
• The antioxidant properties of phytochemicals offer the same protection to the humans that eat them. Plant-based milks contain phenolic compounds and bioactive compounds such as phytosterols and isoflavones that make plant-based milk substitutes an excellent choice. (17)
• Cow’s milk can contain some phytochemicals but it depends on what the cow is eating. Cows that are out on pasture eating grass have been found to have phytochemical levels up to those  of plant-sourced milks.  (18,19)

 

Soy milk is distinctive among plant-sourced milks in that it contains phytoestrogens known as isoflavones (such as genistein, daidzein and glycitein).  Isoflavones are only present in plants and have numerous positive health effects.

 

• Phytoestrogens are similar to estrogen molecules in their structure but have very different health effects. (17)
• Phytoestrogens slow down cancer progression and calm menopause symptoms. They are associated with reductions in the risks of both prostate cancer and breast cancer, lower blood cholesterol, and with decreases in the symptoms of menopause. (17)
• Dairy milk consumption can increase a woman’s risk of breast cancer. Research from 2020 found that drinking as little as ¼ to 1/3 cup of dairy milk every day was associated with an increased risk of breast cancer of 30%; drinking up to 1 cup per day was associated with an increased risk of 50%; and drinking 2 or 3 cups of milk a day increased the risk to 70 to 80%.  (20)
• A 2022 study concluded that consuming soy (and therefore, isoflavones) lowers the incidence and progression of breast cancer. (21)
• A meta-analysis from 2018 demonstrated that soy foods, with their isoflavones (genistein and daidzein) are significantly associated with lower risk of prostate cancer. The authors note that soy consumption may be a powerful dietary approach to reducing prostate cancer.  (22)
• A study from 2015 showed that men who consumed about 430 grams of dairy per day (1 ¾ cups of milk) faced a 25% increased risk of prostate cancer compared to men who consumed only 20.2 grams of dairy per day (1/2 cup of milk per week). Also, men who consumed about 430 grams of dairy per day faced an even greater increase in risk when compared to men with zero dairy intake in their diets. (23)
• Isoflavones also have positive effects on many other diseases including osteoporosis, cardiovascular disease, neurodegenerative disorders and dermatological diseases. (17)

 

 Environmental Impact (1): 

 Plant-based milks are generally associated with lower environmental impacts (e.g., greenhouse gas emissions, water use) than cow’s milk, with the notable exception of the higher water footprint of almond milk.

• Among agricultural products, dairy products rank second highest after meat and meat products in greenhouse emissions.
• A 2016 analysis measured the effects on climate, eutrophication, acidification risk and ecotoxicity when oat milk was produced instead of cow’s milk on a traditional Swedish dairy farm. The result was a 10 to 20% decrease in the effect on climate.  The production of oat-sourced milk created 16 to 41% less greenhouse gas emissions than the production of cow’s milk.  (17)

 

IN SUMMARY:

Soy milk is the plant-based milk most closely aligned with the nutrition found in cow’s milk. Its content of isoflavones also gives it an extra edge in the health benefits available within the category of plant milks.  The physical characteristics of soy milk offer advantages when it comes to using “milk” in cooking and baking.  However, most plant-based milks have benefits over the milk sourced from a cow.

In the USA dairy is considered to be a good source for three of five “nutrients of concern” (nutrients that are lacking in the diets of many Americans) identified in the 2020–2025 US Dietary Guidelines. (25)  These three nutrients are calcium, potassium, and vitamin D, all of which are present in similar levels in plant-sourced milks and dairy milk.  (1)

The other two “nutrients of concern” are dietary fiber and iron.  Cow’s milk is very low in iron and contains no fiber.  Plant-sourced milks are slightly higher in iron than cow’s milk and their iron is in the safer non-heme form.  Plant-based milks contain dietary fiber while dairy milk has none.

Health Canada recommends the regular intake of nutritious foods like vegetables, fruit, whole grains, and plant-sourced protein-containing foods because of their beneficial health effects.  Low intake of such food is considered nutritionally risky. (24)

 

LAST THOUGHTS…

Dairy milk is high in saturated fat and lactose and is associated with increased risks of breast and prostate cancer and cardiovascular disease, among other health concerns.  Dairy milks have higher negative impacts on the environment than plant milks.

Plant-sourced milks supply nutrition comparable to dairy milk but without the associated health risks of milk sourced from cows. (1)  Embracing plant-sourced milks is an excellent way to increase the healthiness of your diet and to lower your impact on our planet.

 

SOURCES

1  Cullimore, J. P., Herby, A. R., Paul-Quinn, J. L., Susan Levin, & Saray Stancic. (2023). The Nutritional Content of Animal and Plant Milks and Their Health Implications. International Journal of Disease Reversal and Prevention, 5(1), 13 pp. https://doi.org/10.22230/ijdrp.2023v5n1a363. See full text at:  https://pmc.ncbi.nlm.nih.gov/articles/PMC10504201/

2  https://myfooddata.com/nutrition-facts

3 https://nutritionsource.hsph.harvard.edu/calcium/#:~:text=For%20example%2C%20dairy%20foods%20have%20a%20bioavailablity%20of,overall%20but%20have%20a%20higher%20bioavailability%20than%20dairy.

4  Zhong, V.W., Van Horn, L., Cornelis, M.C., Wilkins, J.T., Ning, H., Carnethon, M.R., Greenland, P., Mentz, R.J., Tucker, K.L., Zhao, L., Norwood, A.F., Lloyd-Jones, D.M., Allen, N.B. Associations of Dietary Cholesterol or Egg Consumption With Incident Cardiovascular Disease and Mortality. JAMA. 2019 Mar 19;321(11):1081-1095. Doi: 10.1001/jama.2019.1572. PMID: 30874756; PMCID: PMC6439941.

5  https://www.health.harvard.edu/heart-health/the-facts-on-fat-and-heart-health

6  Erlich, M.N., Ghidanac, D., Blanco, Mejia. S., et al. A systematic review and meta-analysis of randomized trials of substituting soymilk for cow’s milk and intermediate cardiometabolic outcomes: understanding the impact of dairy alternatives in the transition to plant-based diets on cardiometabolic health. BMC Med. 2024;22(1):336. doi:10.1186/s12916-024-03524-7

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8  https://longevity.stanford.edu/lifestyle/2024/04/08/what-is-fiber-and-why-is-it-important-for-the-microbiome/

9 Xu, X., Zhang, J., Zhang, Y. et al. Associations between dietary fiber intake and mortality from all causes, cardiovascular disease and cancer: a prospective study. J Transl Med 20, 344 (2022). https://doi.org/10.1186/s12967-022-03558-6.

10  Farvid, M.S., Eliassen, A.H., Cho, E., Liao, X., Chen. W.Y., Willett, W.C. Dietary Fiber Intake in Young Adults and Breast Cancer Risk. Pediatrics. 2016 Mar;137(3):e20151226. Doi: 10.1542/peds.2015-1226. Epub 2016 Feb 1. PMID: 26908709; PMCID: PMC4771124.

11  https://www.aicr.org/resources/blog/ask-the-dietitian-get-your-facts-right-on-fiber-and-whole-grains/

12  Ramsing, R., Santo, R., Kim, B.F. et al. Dairy and Plant-Based Milks: Implications for Nutrition and Planetary Health. Curr Envir Health Rpt 10, 291–302 (2023). https://doi.org/10.1007/s40572-023-00400-z.

13  Xue, T., Wen, J., Wan, Q., Qin, G., Yan, L., Wang, G., Qin, Y., Luo, Z., Tang, X., Huo, Y., et al. Association of soy food with cardiovascular outcomes and all-cause mortality in a Chinese population: a nationwide prospective cohort study. Eur J Nutr 2022.

14  Cook, J.D.  Adaptation in iron metabolism. American Journal of Clinical Nutrition; 15(2): 301 – 308.

15  https://web.archive.org/web/20180830115339/http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/salt/eng/1391790253201/1391795959629?chap=0

16  https://www.ontario.ca/page/colostrum-dairy-calf

17  Aydar, E.F., Tutuncu, S., Ozcelik, B.  Plant-based milk substitutes: Bioactive compounds, conventional and novel processes, bioavailability studies, and health effects.  Journal of Functional Foods. 2020. Volume 70. 103975. ISSN 1756-4646. https://doi.org/10.1016/j.jff.2020.103975.

18  Van Vliet, S., Provenza, F. D., Kronberg, S.L.   Health-Promoting Phytonutrients Are Higher in Grass-Fed Meat and Milk.  Frontiers in Sustainable Food Systems. 2021; Volume 4.  URL=https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2020.555426.  DOI:10.3389/fsufs.2020.555426

19  https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2020.555426/full

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21  Boutas, I., Kontogeorgi, A., Dimitrakakis, C., Kalantaridou, S.N. Soy isoflavones and breast cancer risk: a meta-analysis. In Vivo. 2022;36(2):556-562. Doi:10.21873/invivo.12737.

22  Applegate, C.C., Rowles, J.L., Ranard, K.M., Jeon, S., Erdman, J.W. Soy consumption and the risk of prostate cancer: an updated systematic review and meta-analysis. Nutrients. 2018;10(1):40. doi:10.3390/nu10010040

23  Aune, D. et al.  Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. American Journal of Clinical Nutrition. 2015;101(1):87 – 117.

24  https://food-guide.canada.ca/en/guidelines/section-1-foundation-healthy-eating/

25  https://www.dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials/food-sources-select-nutrients

26  Teas, J., Pino, S., Critchley, A., Braverman, L.E. Variability of iodine content in common commercially available edible seaweeds. Thyroid. 2004;14(10):836-41.

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28   Di Costanzo, M., Canani, R.B. Lactose Intolerance: Common Misunderstandings. Ann Nutr Metab. 19 February 2019; 73 (Suppl. 4): 30–37. https://doi.org/10.1159/000493669.