Interviewees:
Brent Kim, researcher at the Johns Hopkins Center for a Livable Future
Abby Johnson, associate director of the Nutrition Coordinating Center at the University of Minnesota in the School of Public Health
Becky Ramsing, public health nutritional professional, registered dietitian, and senior program officer at Johns Hopkins Center for a Livable Future
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Transcript
[Neil and Sarah meeting at the DW coffee machine in the hallway, Neil buying a coffee, while Sarah is drinking a hazelnut shake.]
Sarah: Hey, Neil.
Neil: Hey Sarah.
Sarah: How's it going?
Neil: I'm just getting the coffee, you know, first coffee of the day. I'm not coffeed up yet. Before I start working.
Sarah: Oh my God. I know that's way too much coffee for me. I have a shake.
Neil; that's that's plant based, is it? What is it?
Sarah: Yeah, it's it's made from pea protein.
Neil: That tastes good?
Sarah: Yeah, actually really good.
Neil: OK, so that’s like a milk substitute?
Sarah: Yeah, yeah, yeah. It's not, it's not dairy.
Neil: Because my wife, she also she's got like an oat milk substitute, which she uses every morning for her for her Muesli. She always used to use dairy milk. But then she switched for environmental reasons. I tried it as well, I must admit. But I didn’t like it.
Sarah: I mean, there's so many choices, you know, soy milk, old milk rice milk, almond milk.
Neil: I’ve seen all of those but I haven't seen pea yet, but which one would be the best to go for from an environmental perspective? Because I've often wondered that - I've seen all these products and my wife also asked me, you know, with me working in the environment section, which one is the best environmentally speaking and I was like: I’m actually I'm not sure.
Sarah: I'm actually not too sure either. I mean, obviously, plant based milks are better in terms of like greenhouse gas emissions, but which one is the best? So I think it's really hard to say. And also you have to look at the nutritional values, right, calcium and stuff like that.
Neil: Exactly, you don't want any calcium deficiency.
Sarah: I mean this one here is fortified. So it has calcium and like a bunch of vitamin B2, B6, B12, like all the essential ones. But I don't know if all have that. I mean, that would actually be a really interesting story to look at, right?
Neil: For our what's better segment, right? You should go for that.
MUSIC
Sarah: So we already know cutting back on meat and dairy would be a huge help in reducing our impact on the climate. Meat and dairy have a very high carbon footprint. It accounts for almost 15 percent of all greenhouse gas emissions, says the United Nations Food and Agriculture Organization. So that plays a big role in heating up our planet.
Brent Kim: "Globally, livestock occupy three quarters of the world's agricultural land, and most of that three quarters is for grazing land. And that presents a challenge for us, because, globally, the population is still growing and there are estimates that suggest we need to increase agricultural output by 50 to 60%. The challenge that we are facing is that all of the agricultural land that we could grow food on is already being used for agriculture."
That's Brent Kim, a researcher at the Johns Hopkins Center for a Livable Future and one of the authors of Dairy and Plant-Based Milks: Implications for Nutrition and Planetary Health.
Brent Kim: "We can't expand agricultural production without clearing forests, and that becomes a climate disaster, right. Because all of those trees are essentially sequestering or holding on to carbon. So if we burn or clear those forests for more agriculture, we're releasing all that carbon into the atmosphere. So part of the challenge for us is that not that grazing animals are bad. There are certainly times and places where it makes good sense to have grazing animals, right.
They can graze on land that's too hilly or too rocky for growing crops and grazing animals can also convert something that humans can't eat, which is grass, into something we can, which is meat and milk. So I have to defend grazing animals a little bit, but at the same time knowing that they occupy 3/4 of the world's agricultural land, we have to rethink that a little bit and find ways to use at least some of that land more efficiently. Which means using that land to grow food directly for humans, whether that's growing plants that we eat or growing plants that become plant milk, or plants that become plant-based meats, right, we have to use some of that land more efficiently if we're going to both feed the population and avoid the worst-case climate change scenarios."
Sarah: On the other hand, cow’s milk comes with a lot of nutritious benefits. It provides protein, Calcium and Vitamin D, just to name a few. Can plant-based milks really substitute all that? A recent study done by the University of Minnesota's Nutrition Coordinating Center says most of them can't. The scientists looked at 219 different plant-based milks from 21 brands available in the US … and found that most could not compare to milk when it comes to nutritional values.
Abby Johnson: "In countries like the United States, where our food based guidelines incorporate, say, 3 servings of dairy as part of the overall recommendation, and we are built to these guidelines around expecting that people are getting calcium and vitamin D for example, from the milks here in the US which are fortified with vitamin D and naturally provide calcium, if a person substituted out cow's milk for plant based milk, they might not be getting the same amount of calcium or vitamin D as they were thinking that they would be getting."
That's Abby Johnson, associate director of the Nutrition Coordinating Center at the University of Minnesota in the School of Public Health. She's the lead author of that study I just mentioned. As plant-based milks exploded in the marketplace, Abby and her team wanted to update their nutrition database and see how these milk alternatives compare.
Abby Johnson: "I think that the tension between plant-based and ultra processed or processed foods right now in the consumer space and in the research space is quite interesting. There is a lot of benefit from choosing potentially planetary health, kind of making those choices that might be good for the planet by moving towards a more plant-based diet. But then we've got this other piece of the puzzle with a lot of focus and interest on reducing processed foods. And so how do we find kind of a happy point in the middle somewhere, perhaps where you're minimizing both intake of highly processed foods and increasing the intake of plant-based products to be sort of conscious of the environmental impact of the choices that you're making?"
Sarah: So let's look at these choices in this What’s better segment here on Living Planet. We’ll check out different kinds of milks and their impact on the environment AND our bodies.
First things first: It's been well-established that raising cattle takes up a lot of resources. We need water and land to sustain them, and even more land to grow crops that we then use as animal feed. Cows also burp and fart and emit a lot of methane, a potent greenhouse gas. Methane is about 28 times as potent as carbon dioxide or CO2. That’s according to the United States Environmental Protection Agency. So methane is 28 times as good at trapping heat in the atmosphere. That means fewer cows would definitely be better for our climate.
But is there even a clear winner on the side of plant-based milks?
Let's ask Brent Kim, who worked on that meta study. So which one is better? Is there a choice that's best?
Brent Kim: "I think the question that you asked comes up a lot, right? People are at the coffee shop and they want to add a milk to their coffee. What kind of milk is best, and it's a little bit difficult and nuanced to answer the question of which one is best, because you have to consider when we say best, what do we mean? Do we mean the smallest climate change impact? Do we mean the most nutritious milk, the most affordable milk or maybe more concerned about how much fresh water was used to produce that milk? Or maybe how much agricultural land had to be occupied to produce that milk.
Sarah: The scientists compared median per liter greenhouse gas emissions associated with soy, oat, almond, spelt, pea and coconut milks and found they were 62 percent to 78 percent lower than those associated with cow's milk. The only outlier among plant-based milks was rice milk – however, that was only based on one study.
Plant-based foods have by far the lowest carbon footprint – but we should also clarify that doesn't just mean CO2. And Kim says the vast majority of those greenhouse gas emissions that come from food and agriculture are actually produced BEFORE the product leaves the farm. The packaging the milk comes in or the miles it's traveled to get to the grocery store aren't as important as what happens ON the farm. I'm surprised that transportation doesn't play a bigger role…
Brent Kim: "A lot of people will assume that, and I think that's partly because a lot of the focus on climate change is on carbon dioxide. When we think of a climate change, we use the term carbon footprint, so there's a lot of focus on carbon in our vocabulary, and that's appropriate because carbon dioxide is hugely concerning and globally it is the number one greenhouse gas in terms of its contributions. However, within the context of Food and Agriculture, most of the greenhouse gases are in the form of methane and nitrous oxide."
These two other what we call short lived but extremely potent gases that per unit of mass, contribute to much more warming than carbon dioxide for the for the same amount of mass. So within, you know, we're talking about talking about methane. That's from cattle burps or enteric fermentation is just a fancy name for a process that's unique to rumen animals like cows, sheep and goats, right. by the way, they break down fibers in their digestive system, that process that process releases methane, this potent greenhouse gas, and they burp it out.
Manure is another major source of methane and also nitrous oxide, two very powerful greenhouse gases. So we have all these different processes associated with raising animals that release these very potent greenhouse gases that contribute much more to greenhouse gas emissions from Food and Agriculture as compared to maybe the truck that's driving the food that's causing the food miles. Not that food miles don't matter, but when you're looking at the total, the food miles and the packaging are a much smaller fraction of the total greenhouse gas emissions for Food and Agriculture. If we're talking cars, that's a very different story."
Sarah: There are different environmental trade-offs when it comes to plant-based milks, too. While almond milk compares favorably to cow's milk when it comes to greenhouse gas emissions… it doesn't look so good if you factor in its water footprint. And almond milk is the most sold plant-based milk in the US at the moment… Isn't there a better option?
Brent Kim: "One of the better ones I feel is milk made from peas. That might sound a little bit strange. Pea milk sounds kind of funny, but it was one of the least greenhouse gas intensive milks to produce, and it was also one of the more protein dense plant milks. And if we're concerned about freshwater use, which we certainly should be, it had one of the smallest what we call water footprints of all the different milks.”
Sarah: That's actually really good to know. I myself have been rotating milks quite a bit – and I found a new favorite in that aforementioned protein shake made from pea protein. I actually chose that because I wasn't really getting enough protein and I wanted to reduce my dairy intake. But just looking at the numbers, I think soy milk also doesn't look too bad. What about soy milk?
Brent Kim: "It's difficult to pick one best one… I think pea milk performs well on low greenhouse gas emissions, low freshwater use and high protein content. But soy milk checks all of those boxes as well. There were some studies where soy milk was not as low in terms of climate impact compared to pea, but there's also been a lot more research on soy milk than there has been on pea milk, so I think we need some more research on these different milk types to say with more confidence really which one is best."
Becky Ramsing: "Soy milk is still a winner and I would say pea protein is a really a winner environmentally because it's a legume, but it's not a milk that you can get very easily, it's not available as much. Ripple brand is pea protein milk and there's some plant-based milks in the United States that have some combination of protein. But I would say, you know, I would love to see more pea protein milk out in, in the in the in the markets."
Sarah: That's Becky Ramsing, a public health nutritional professional, registered dietitian, and senior program officer at Johns Hopkins Center for a Livable Future. She looked at the nutritional side of things in the study.
So why haven't we seen more plant-based milk from pea protein yet?
Becky Ramsing: "Yeah, I don't know, is it the marketing… in English, pea milk that doesn't sound very good. it's the marketing and it hasn't really picked up. You've seen Oatly came in with such a great marketing plan and presentation and they really picked up and so it's gonna take something like that to shift the conversation."
Sarah: I think it's also time for us to shift the conversation towards nutrition. What kind of milk is actually better for our bodies? There are some notable differences, particularly when it comes to protein that we've already delved into a bit, but also zinc and potassium and other vitamins. Some plant-based milks also have added sugar in them which isn't too great.
Can we say straight off the bat which milk is best? Abby Johnson who looked at over 200 different plant-based milks, says that's difficult.
Abby Johnson: "There's a lot of variability. Every plant-based milk, it seems, is formulated differently. There's a lot of differences in terms of their nutritional content and what they provide depending on how the brands have supplemented or fortified the milks with different nutrients and so you can't really say anything concrete about plant-based milks as a category overall and even within categories like if we think about soy milk, if we think about oat milk and almond milk, even within categories, there's a lot of variability in terms of their nutritional content and generally they're not a one to one substitution or replacement for Dairy Milk."
Sarah: Dairy is considered a good source for three of five nutrients of concern identified in the 2020–2025 US Dietary Guidelines: calcium, potassium, and vitamin D. So it looks like cow’s milk is the clear winner here, from a nutritious point of view, right?
Becky Ramsing: "Yes, yes, with caveats. I think especially for growing children, especially in areas where people struggle to have a variety of food to purchase and be able to access a variety of foods. And dairy is really important because it provides a good amount of proteins: the calcium, the vitamin D's just are important for development and the affordability of it. If you look at, you know, the affordability of all those nutrients are much lower compared to these plant based proteins. So definitely in terms of, if you need protein in in you're growing and developing, I would definitely put dairy as a clear winner. But as you get older and you, if someone who has access to a lot of different varieties of plant-based milks and are able to afford them, I think you can do fine."
Sarah: A lot of plant-based milks have been fortified to include vitamins. Is that as good as the real deal?
Becky Ramsing: "The fortified nutrients are just as impactful as the naturally occurring nutrients in that in that item… I mean even the dairy milk we have in the United States is fortified with A&D, vitamin A and vitamin D, I mean vitamin D is not natural in milk. It is fortified. And that's what we've done throughout for public health reasons to meet the needs for vitamin D because they're really not very many foods that have vitamin D in them at all."
Sarah: One thing to certainly pay attention to is added sugar.
Abby Johnson: "Dairy milk, cow's milk, is naturally sweet, but it is sweetened with lactose. (…) So what we looked at was added sugars, which have a specific definition per the FDA in the US and we found that there was again wide variability in the added sugar in these plant-based milks, some of which sort of looks more like a chocolate milk or a strawberry milk level of added sugar for example."
Sarah: And that sugar intake can add up quickly, depending on which brand you choose, says Abby Johnson.
Abby Johnson: "In our sample of milks that we looked at, if we look just at soy for example, some of the soy milks are high in added sugar where they might be providing up to 30% of the daily value for added sugar from a serving of soy milk, while others have a much lower amount and are providing almost no added sugar. It really depends even within a category on the actual makeup of that milk and you have to read the label to figure out if your particular soy milk has added sugar or not."
Sarah: It definitely pays off to read the label. Not just to check out the sugar amount, but also for vitamins and protein. There's a nice, neat chart comparing different plant-based milks…and just to give you an idea of the dimensions: so a glass of cow's milk, that's measured at 240 ml or just over 8 ounces, had about 8 grams of protein. Pea milk had 7.5, soy milk just around 6, oat milk just under 3 and almond milk had just one gram of protein.
Becky Ramsing: "Oats are not necessarily a high protein food. They're green and so that, even as healthy as oatmeal is or oats are, that is a milk is not going to provide a lot of protein. And almonds, especially interesting enough, it's the almond milk is very cause you think of nuts as being a high higher protein food. But the way that the milks are made, there's a lot of water added to that. So the protein that content actually is very low. So it's definitely not a good if you're not getting the protein if you're relying on that dairy or that plant based dairy for protein, you're not going to get it in those choices."
Sarah: Abby Johnson says they found some plant-based milks that were similar to cow's milk.
Abby Johnson: "Soy milk typically has higher protein levels. We found some higher protein levels in pea-based plant-based milks as well as some of the blends that have different combinations of plant sources of protein."
Sarah: A lack of protein might particularly come into play for children, Becky Ramsing says.
Becky Ramsing: "And you think about children who need on getting a lot of protein and need that protein if they're, if they're getting or 12 grams of from a cup of dairy milk. And instead, three times a day they're going to almond milk. They're losing like 30 or 40 grams of protein that are extremely important for them. If they're doing that throughout the day and every day, so that adds up."
Sarah: For grown-ups, that might be not so much of a problem though.
Brent Kim: "The average American gets at least in the United States far they far exceed the amount of protein that they need for a healthy diet. So in the United States, on average, Americans are overconsuming protein."
So it's not as big of a concern from a nutritional component now on the other hand, obviously, if we're talking about, you know, developing children or people in countries where they may be at risk of protein deficiency, that's a very different story. Whereas some people might say, well, I'm already getting plenty of protein, I just want something tasty to combine with my cereal, in which case oat milk or coconut milk would be perfectly fine for those purposes."
Becky Ramsing: "You can't just pick a plant-based milk off the shelf and assume that's gonna fit one profile. Everyone is so different and I think that's really the message of this is, you know, to help consumers get this, how do I look for added sugar or how do I look for protein? How do I look for what's fortified in that product?"
Sarah: And she says she's experienced that firsthand that it's important to check.
Becky Ramsing: "There was a soy milk I was drinking and because it was hard to get unflavored ones, and soy milk is getting harder to get now in the store because almond milk and oatmilk are so big, and here I am, Oh yeah, I'm getting my calcium. And then I looked. I'm like, oh, wait, this one not calcium fortified. So I yeah, so that you have to look at that label and make sure that it is calcium fortified because calcium is important for bone health."
One advantage of plant-based milks that cow's milk doesn't have is extra fiber. Abby Johnson says there some plant-based milks that provided more than 10 percent of the daily value of fiber – and cow's milk has none.
On the other hand, cow's milk is rich in vitamin B2 or Riboflavin that's important for cell growth and energy production; and phosphorus that's important for our bones and teeth.
Abby Johnson: "For most of the pea products in our data set - there were nine - and most of them met the criteria for calcium and protein, but only three met the criteria for vitamin A and none of the pea-based products meet the criteria for phosphorus or riboflavin, so there are other nutrients that were lower even though the protein is high."
Sarah: But you can still drink that type of plant-based milk if you get your nutrients elsewhere.
Abby Johnson: "Eat a diverse diet with lots of fruits and vegetables and you wouldn't have to worry about being deficient in either vitamin B2 or in phosphorus. So it's not to say that you can't consume plant-based milks because you definitely can, and they can definitely be part of a healthy diet. It's more thinking holistically about everything you're eating and not relying on them as the only source of nutrients.”
MUSIC
Sarah: So what do the experts themselves drink?
Abby Johnson: "So I personally do consume dairy milk. I just don't like the flavor of plant-based milks myself, but I have in the past drink soy milk."
Becky Ramsing: "I do a combination. I like yogurts and I think the yogurts in the cheeses are healthy. I don't see a lot of reason to drink dairy milk. I don't enjoy it as much anymore, so I stick more the yogurts, cheeses, and then I do I like soy milk and so I will drink soy milk or pea protein milk just for that environment. I'll just to really help on the environmental side of things and so trying to keep my dairy minimal and enjoy it."
Brent Kim: "I will admit that I am a personal fan of milk made from peas. There happens to be a store that's close to my home that does the stock those milks, and I acknowledge that not everyone has that privilege of having both physical access as well as economic affordability, access to all of this range of different products. So that's an important consideration too. But in terms of personal preference, I do like that it's richer and creamier. I think coconut milk and almond milk can sometimes seem a little bit watery, and it's not as satisfying, but that's, you know, everyone's gonna have a different personal preference."
Sarah: So there you have it Neil. Check the label, check what you need in terms of nutrition and watch out for hidden sugar.
Outro and credits