Culinary Medicine
by Lori A Smolin, PhD and
The popularity of plant-based milk is on the rise. Currently, 40% of U.S. households have purchased plant-based milk products despite the fact that they cost more than dairy milk.[1,2] Some consumers choose these plant-based, or non-dairy, milks to avoid symptoms from lactose intolerance or a milk allergy. Others choose them because they want to reduce their reliance on animal products for ethical reasons, they believe these products to be a healthier alternative to dairy, or they want a more sustainable product. How do plant-based milks stack up against dairy?
There are a growing number of plant-based milks to choose from including almond, soy, hemp, rice, coconut, pea, oat, macadamia, and cashew milks. They are all designed to mimic the appearance, texture, and taste of dairy milk but none are actually milk, which, by definition, is secreted from the mammary glands of mammals. Non-dairy milks are typically made by soaking the legume, nut, grain, or other main ingredient in water, blending the mixture to form a puree, heating it, and then pressing and straining out the liquid to form the “milk” base. Sugars, flavors, thickeners, and other substances are added to improve taste and texture. All these products are a safe choice for those with lactose intolerance or milk allergies because they don’t contain lactose or milk proteins. However, if you are using a plant-based milk with the expectation that it is nutritionally equivalent or has less environmental impact than cow’s milk you need to choose carefully.
How do the Nutrients in Plant-Based Milks Compare with Dairy?
Dairy milk is an important source of protein, calcium, riboflavin and vitamins D and B12. Most of these nutrients occur naturally in milk and a few, such as vitamins A and D, are added to dairy milk products. Non-dairy milks do not necessarily provide a similar nutrient profile. The nutrients in plant-based milks depend on the nutrients in the plants from which they are made, and any nutrients lost or added during processing.[3] For example, rice is naturally low in protein, so rice milk is also low in protein whereas peas and soybeans are high in protein, making pea and soy milks good protein sources. Almond milk is a good example of nutrient loss in processing. Almonds are high in protein and a good source of healthy fats, calcium, fiber, and iron. But not all of these end up in almond milk because the process of making it leaves much of the protein, healthy fats, fiber, calcium, and iron behind and dilutes what remains with a lot of water. None of the non-dairy milks are naturally good sources of calcium, vitamin D, vitamin A, or vitamin B12 and the addition of nutrients to these products is not regulated, so which nutrients are added is at the discretion of the manufacturer. As a result, you can buy a plant-based milk that provides over 100% of the Daily Value for vitamin B12 or one that has no vitamin B12 (see Table).
*%DV or % Daily Value is the amount of a nutrient in a food as a percentage of the amount recommended for a 2000-Calorie diet.
Are Plant-Based Milks Better for the Environment than Dairy?
Dairy products make a significant contribution to greenhouse gas emissions because cows belch methane gas and decomposing cow manure releases additional methane into the atmosphere. Methane is almost thirty times as potent as carbon dioxide in terms of warming the atmosphere.[4] In addition, raising dairy cows uses significant land and water resources and runoff from farms can pollute waterways.[3,4] Plant-based milks generally have less of an environmental impact than cow’s milk, but the impact each product has varies depending on the metric examined. For example, almond milk has one of the lowest greenhouse gas contributions of any non-dairy milk, but growing almonds is costly in terms of water use. Soy milk produces similar greenhouse gas emissions to almond milk but uses very little water. However, current soy farming practices require large amounts of land, reduce biological diversity, and contribute to soil depletion.[4] Oat milk is one of the least impactful, in terms of land use and greenhouse gases requiring 80% less land and producing 80% fewer greenhouse gases than cow’s milk. But like soy most oats are grown in ways that are costly in terms of land use and soil depletion. Determining which is the most sustainable choice is complicated, but whether you choose dairy or non-dairy milk, you can minimize your environmental impact by purchasing only what you will use; food waste is an important contributor to greenhouse gas emissions.
Which Plant-Based Milk Will Meet Your Needs
The plant-based milk that is best for you depends on how it fits into your overall dietary pattern. Most Americans get plenty of protein, but if you rely on milk to meet your protein needs, choose a soy or pea-based product rather than rice, almond, or coconut milk (see table). If you are switching to a plant-based milk over concern for your heart health, you may want to avoid coconut milk; it has more heart-unhealthy saturated fat than low-fat cow’s milk. If you are trying to limit your intake of added sugars, check the label before you choose a plant-based milk; some have little or no added sugars, but others can be quite high. If you avoid all animal products, look for a non-dairy milk that is fortified with calcium and vitamins D and B12; these are nutrients at risk of deficiency in a vegan diet. Check the the Nutrition Facts panel of the product’s food label to find the amounts of protein, saturated fat, added sugars, calcium, and vitamin D. Vitamin B12 is not required on the Nutrition Facts panel, so you may need to check the Ingredient list to see if your choice has vitamin B12, also called cobalamin. The Ingredients list also includes any added preservatives, colors, sweeteners, and flavorings.
The bottom line as to which is best for you depends on what you are looking for in a plant-based milk. If you are trying to reduce your consumption of animal products, all meet this goal. If you want a more sustainable option, consider not only how it is produced but whether it is packaged in a recyclable container. If you expect it to help meet your protein needs or to supply vitamin B12 or calcium, use the food label to sleuth out the nutrients it provides. And, make sure you choose a product that provides the appearance, taste, texture that suits you. It won’t provide any nutrients if you don’t drink it.
References
[1] Plant Based Foods Association. 2022 U.S. retail sales data for the plant-based foods industry.
https://www.plantbasedfoods.org/2022-u-s-retail-sales-data-for-the-plant-based-foods-industry/#:~:text=In%202022%2C%20the%20plant%2Dbased,based%20milk%20impacted%20overall%20purchasing. Accessed November 6, 2023.
[2] The Guardian. Oat milk is everywhere. Why is it still so expensive?
[3] Ramsing R, Santo R, Kim BF, et al. Dairy and Plant-Based Milks: Implications for Nutrition and Planetary Health [published online ahead of print, 2023 Jun 10]. Curr Environ Health Rep. 2023;10.1007/s40572-023-00400-z. doi:10.1007/s40572-023-00400-z.
[4] Mulvaney, K. National Geographic. Is your favourite plant-based milk good for the planet? Here's how they compare. Dec2, 2022.