Most plant-based milks don't deliver the same amount of nutrients as cow's milk, says new study

Plant-based milks have exploded in popularity in the past few years, giving shoppers plenty of options at the grocery store. But although they have taken over entire sections of many dairy aisles, new research has found that most plant-based milks on the market don't necessarily have the level of nutrients you'd get in cow's milk.

Why might that be the case, and what does this mean for your plant-based milk habit? Here's the deal.

What the study says

The study, which was conducted by researchers at the University of Minnesota and presented at the American Society for Nutrition's Nutrition 2023 annual conference, found that very few plant-based milks have nutritional value equivalent to cow's milk.

What are the key findings?

The study analyzed nutrition information from 237 milk alternative products — including almond, rice, oat, pea and soy milks — and found that only 12% had amounts of calcium, vitamin D and protein comparable to or greater than cow's milk.

Nearly two-thirds of the plant-based milks in the study were made from almonds, oats or soy, and 170 of them were fortified with both calcium and vitamin D, giving them levels comparable to cow's milk. But only 38 (16%) of the plant-based milks had protein levels that were greater than or equal to the 8 grams of protein per 240 milliliter in cow's milk, with soy and pea milks being the most likely to have higher levels of protein.

"Plant-based milks are not a one-to-one substitution for cow's milk," lead study author and registered dietitian Abigail Johnson, an assistant professor and associate director of the University of Minnesota School of Public Health Nutrition Coordinating Center, tells Yahoo Life.

What experts think

Nutritionists say they're not surprised. "It's hard to outdo nature, and plant-based milks will struggle to be as nutritious as animal milk," Gina Keatley, a nutritionist and co-owner of Keatley Medical Nutrition Therapy, tells Yahoo Life. "That's not to say there isn't a place for these products — it's just that they should be used with an understanding of their limitations."

Jessica Cording, a registered dietitian and author of The Little Book of Game-Changers, tells Yahoo Life that plant-based milks "have a health halo around them," but adds: "These milks don't have the same nutrient profile that someone may be looking to get from dairy milk — those have to be added."

Plant-based milks also usually have added ingredients to try to help turn the product into something that has a taste and texture similar to cow's milk, Cording says. "That's why you really need to look at the label to decide if it's the right fit," she says.

There's also flexibility in terms of levels of nutrients in each brand of plant-based milk, while "Cow's milk is tightly regulated and must be delivered hitting specific numbers," Keatley explains. As a result, you can end up having very different nutritional results from product to product with plant-based milks.

However, plant-based milks are a good option for people with a lactose intolerance or sensitivity.

Why it matters

Johnson says the big takeaway from her work is that people shouldn't assume that all plant-based milks are as nutritious as cow's milk. "Calcium and vitamin D are the main nutrients people look for in dairy," she says. "If people aren't getting calcium and vitamin D from other parts of their diet — say, tofu or sardines — we recommend that they look at labels and see if they can find a product that has vitamin D and calcium as ingredients." Most people can get protein from other sources in their diet, she adds.

But Cording says a lot depends on what you're hoping to get out of your plant-based milk. "If you're just looking for something to put in your coffee and aren't looking for satiety or nutritional value, that gives you more flexibility," she says. "But if you want something that you can use interchangeably with milk, you'll want to look for calcium, vitamin D and protein on the label."

If you need to use plant-based milk as a milk substitute, it's a good idea to be aware of what's in it, registered dietitian Deborah Cohen, an associate professor in the department of clinical and preventive nutrition sciences at Rutgers University School of Health Professions, tells Yahoo Life. "People, especially vegetarians and vegans, women, and older folks who are at risk for lower intakes of calcium and vitamin D, need to be aware," she says. "Intake of both calcium and vitamin D in the U.S. is lower than recommended and both are important for bone health, as well as many other important functions in the body."

But, as Cohen points out, "Folks can take supplements of these nutrients if needed."

Unsure where to start? Cording suggests looking at pea milk. "These milks have a very palatable taste and texture, and the amount of protein is comparable to what you'll get in a dairy milk," she says.

If you want a plant-based milk with nutritional value similar to cow's milk, Keatley suggests looking for something with about 300 milligrams of calcium per 8-ounce serving, 100 IU of vitamin D and 8 grams of protein. "You should have no more than 14 grams of sugar, natural and added combined," she says.

Johnson stresses that her findings don't mean that people shouldn't use plant-based milks, just that you should be mindful of what's in your go-to milk. "These can fit in a dietary pattern as long as you're taking steps to consider your overall diet," she says.

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