With an array of options showing up on store shelves, more people are turning to plant-based milk than ever before. The alternatives are advertised as nourishing, but little research has been done on the nutrition of non-dairy milk beverages.
Consumers also often think that the alternatives are a nutritionally-sound substitute for cow’s milk—an assumption that research suggests may not be true.
A new study highlights the nutritional differences between plant-based milk and dairy milk and makes the case for why we need nutritional standards for plant-based beverages.
What Are Plant-Based Beverages?
A 2020 study points out that unlike cow’s milk dairy—which is derived from mammary glands of female cows—plant-based beverages or “milk” are extracts of legumes, oilseeds, cereals, or pseudocereals that resemble cow’s milk in appearance (that is, white and of a similar consistency).
The milk products are produced by reducing the size of the raw material and processing it with liquid. Occasionally, ingredients like sugar, oil, and flavorings are added to make the milk have a pleasing taste that is more acceptable to consumers.
While plant-based beverages can be a healthy part of a balanced diet, some people consider them to be a cow’s milk replacement and think that they have the same nutritional value as dairy milk.
However, the non-dairy substitutes have different sensory characteristics, stability, and nutritional composition from cow’s milk. Plant-based milk alternatives are not simply dairy milk without milk proteins, lactose, and saturated fat.
Laura Buxenbaum, MPH, RD, LDN, a registered dietitian and Director of Food and Nutrition Outreach for The Dairy Alliance, told Verywell that “consumers are choosing non-dairy milks with increasing frequency for a number of reasons, but it is important to understand that these beverages often are not the complete nutritional equivalent of cow’s milk, nor do they have the same long track record of research supporting their health benefits.”
Buxenbaum highlighted that real dairy milk provides a “powerful package of 13 essential nutrients,” including vitamin A, vitamin D, zinc, selenium, and protein."
Milk Options Are Not Created Equal
The traditional definition defines milk as a “whitish fluid, rich in fat and protein, secreted by mammary glands of female mammals for the nourishment of their young, and taken from cows, sheep, etc., as an article of [the] human diet.”
However, the use of the term is not regulated, which means that the word “milk” is often used to describe any liquid that is splashed on cold cereal, poured into a cup of coffee, or used to whip up a fancy latte. Therefore, many consumers are not aware that dairy milk and plant-based beverages that are used as milk alternatives are not one and the same when it comes to nutrition.
“The misconception that plant-based milk alternatives provide exactly the same nutrients as dairy milk can ultimately result in nutrient gaps for certain individuals," Melissa Azzaro, RDN, LD, a registered dietitian and the host of the Hormonally Yours podcast, told Verywell. “[This] highlights the need for this term to be better regulated.”
For example, while dairy milk contains 8 grams of protein per serving, many alternatives that are plant-based have as little as 1 gram. In the United States, only pea and soy milk have a protein content that approximates that of cow’s milk.
Also, unlike plant-based alternatives, natural dairy milk contains many bioactive and specific proteins which support weight management. Plus, the unique carbohydrate found in milk—lactose—has been shown to help support calcium absorption in mammals.
Proposed Nutritional Standards
Many plant-based beverages are positioned as milk alternatives even if they are not supplying equal nutrition.
To address the gap in nutrition and knowledge, nutrition experts have proposed criteria that plant-based beverages need to meet to help consumers make sure that they get the key nutrients that are typically found in cow’s milk from the products they use as alternatives without also getting large amounts of saturated fat or added sugars.
The proposed standards were published in Frontiers in Nutrition in October 2021.
Sodium: Less than 120 milligrams Added sugar: Less than 6. 25 gramsCalories: Less than 100 Saturated fat: Less than 0. 75 gramsCalcium: Greater than 75 milligramsVitamin A: Greater than 200 micrograms (IU)Vitamin B12: Greater than 0. 18 mcgProtein: Greater than 2. 2 gramsVitamin D: Greater than 45 micrograms (IU)Vitamin B2: Greater than 0. 09 milligrams
Does Any Plant-Based Milk Meet the Criteria?
To evaluate how the nutritional components of plant-based beverages compared to the proposed standards (which were derived from evaluating 1% cow’s milk) the researchers analyzed over 600 dairy-free beverage options which included different brands of almond, coconut, soy, cashew, tree nut, flax/hemp, pea, quinoa, and rice milk.
Almost all of the options that the researchers looked at met the criteria for calories and sodium, and over 70% met the criteria for added sugar (meaning they did not provide excessive amounts).
On the other hand, the criteria for riboflavin (vitamin B2), protein, vitamin D, and vitamin B12 were met by fewer than 50% of the evaluated milk types, and the recommended amount of calcium was met in fewer than 60%.
Only 102 (16%) of the plant-based beverages contained riboflavin and none contained the nutrient in the proposed amounts. Additionally, few plant-based beverages met the proposed standards for protein and vitamin D.
The Most Nutritious Option
Cow’s milk is the principal source of dietary calcium and vitamin D in the U.S. and it contains multiple minerals critical to bone health. Milk is also an important source of dietary potassium, iodine, riboflavin, and vitamin A.
For people who avoid cow’s milk—for example, because they are allergic or are making a lifestyle change— having nutritionally-sound non-dairy alternatives is important. However, as research has shown, not all plant-based beverages that are marketed as being milk alternatives come close to providing the nutrients that cow’s milk provides.
Soy milk seems to be your best bet in terms of the non-dairy options that come closes to the proposed standards for nutrition.
In the U.S., soy milk products have a relatively high protein content and are fortified with calcium, vitamin A, and vitamin D at levels comparable to milk. You can be sure that these nutrients are consistent because fortified soy milk is assigned by the U.S. Department of Agriculture to the Dairy Group whereas other plant-based beverages are not.
Nutritionally speaking, soy milk is one option that is consistently fortified with many key nutrients and can be a good option, even if it does not replace cow’s milk.
