A few things about cow’s milk:
- Out of the 1.5 billion cattle worldwide, around 270 million are dairy cows.
- It takes about 628 liters of water to produce one liter of milk.
- Cows produce methane, which contributes significantly to global warming.
- Science magazine estimates that dairy produces three times more greenhouse gas emissions than plant-based milks. (Source: https://www.livekindly.co)
What about non-dairy milks?
There are countless non-dairy alternatives on the shelves these days. Plant milks have actually been around for centuries. If you have dietary restrictions, allergies, or intolerances to dairy, gluten, soy, or nuts, or you shun cow’s milk because you are vegan or want to avoid pesticides, hormones, or antibiotics, there is an alternative milk product for you!
Which milks are the most sustainable?
Assessing the environmental impact of plant-based milks is a bit more complicated. There are variables like greenhouse gas, emissions, water use, land use, chemical runoff, and soil degradation. Each stage of production -- growing the ingredients, processing them, and transporting them around the world -- varies from brand to brand. LCA studies* can be biased depending on who funds them, especially if it benefits the dairy industry. And then we must take into consideration the nutritional value of each in proportion to the environmental burden.
According to www.ediblebrooklyn.com, one researcher says, “Plant milk substitutes have a lower impact on the climate and require less land to produce, but the issue is more complex as cow’s milk contains several key nutrients that are challenging to replace.” Any item in your grocery store that takes up water and resources to process, truck, and distribute will make your carbon footprint worse no matter what.
Let’s explore some non-dairy substitutes and their nutritional benefits and environmental impacts below.
Soy milk is made from soybeans, and it’s taste, texture, and nutritional profile make it a great substitute for cow’s milk in cooking, coffee, and cereal. One cup provides 7 grams of "complete protein" (meaning it provides all essential amino acids), which is comparable to cow’s milk at 8 grams per cup. Soy consumption can be beneficial to health, especially for women, but because the isoflavones in soy affect estrogen receptors in the body there is controversy over consuming large amounts. Soybeans use less than a tenth of the water almonds do but require a lot of land compared to almonds or rice, including cleared Amazonian rainforests. Brands like Silk source only from the U.S. or Canada. Be sure to look for GMO-free and organic labels too because soybeans have been genetically engineered to withstand the herbicide glyphosate (e.g. Roundup).
A significant issue with almond milk is that almonds have a large water footprint (3.2 gallons of water per one almond). California produces about 80% of the world’s almond supply, and our state is in extreme drought right now. See THIS.
It is worth noting that there is some “truth or myth” controversy on almonds. THIS ARTICLE (see links at bottom of article as well) provides statistics that water usage is all relative: “It may seem outrageous that a single almond requires about 1 gallon of water to produce (a serving is 23 almonds) – but not when you consider that a single egg requires 53 gallons, a hamburger 660, and a gallon of dairy milk 880 gallons of water to produce.” It also asserts that almonds are consumed sparingly by comparison. The majority of almond milk brands contain mostly water and only 2% almonds. Either way, there are more sustainable options. Nutritionally speaking, almond milk is the lowest calorie non-dairy option, and it contains healthy, unsaturated fats, and Vitamin E. But it contains only 1 gram of protein per cup, and almonds also contain phyctic acid, which binds to calcium, iron, and zinc, so it decreases your body’s absorption of these. In 2020, an article in The Guardian linked almond production directly to the deaths of billions of bees.
The rising superstar of plant-milks is oat milk, which is naturally mild and sweet and often preferred over other alt milks, especially in coffee, smoothies, and cereal. Grown in temperate regions such as North America and the UK, it is not associated with deforestation in developing countries. A University of Oxford study says it uses minimal water and land and is more environmentally friendly than rice, soy, or dairy, although it produces slightly more emissions than almond milk. It is high in protein and fiber but contains a comparable number of calories to cow’s milk, and it may have higher gluten contamination.
Studies have shown that oat milk contains a soluble fiber called beta-glucans that can help lower cholesterol and blood sugar levels. One downside is that oats are often sprayed with Roundup right before harvest, although the Swedish oat milk company Oatly says their suppliers don’t allow their growers to use glyphosate. Their published sustainability report (SEE HERE) says their oat milk uses 60% less energy compared to cow’s milk, 80% less land, and the least amount of water of all the plants turned into milk. If you’re interested in celebrating some version of National Ice Cream Day on July 18 (or any other day), you can find Oatley oatmilks and frozen desserts at Safeway. If you want to bypass the carbon footprint issue, here's an oat milk recipe you can make from home!
Rice milk is high in water requirement, only third after dairy and almond milk. It needs less land than dairy, oat, soy, or almond milks but emissions from the global rice industry give it a large carbon footprint. Nutritionally, rice milk is the least allergenic of plant milks and has about the same amount of Vitamin D, calcium, and calories as cow’s milk, but it lacks protein, with only about 1 gram per cup, so it’s not the best option for growing children, pregnant women, athletes, or the elderly. Its flavor is mild and neutral and its texture is more watery. Rice naturally contains low levels of arsenic.
Coconut is a common ingredient in Southeast Asia and India and coconut milk is popular for being creamy and sweet. The industry operates exclusively in tropical countries and has a history of rainforest destruction and worker exploitation, so choose Fair Trade certified products. Young, growing coconut trees use minimal water and absorb carbon dioxide. Coconut milk has about the same amount of saturated fat as whole cow’s milk but only 1 gram of protein per cup and little calcium. It does, however, provide 30% of your daily value of Vitamin D and 50% of Vitamin B-12 when fortified.
Hemp milk is an up-and-coming plant-based milk made from shelled hemp seeds of the hemp plant (the same species used to make marijuana but without the mind-altering effects of THC). It’s thin, watery texture works well as a substitute for skim milk, although some people do not like it’s nutty flavor. It contains calcium, Vitamin D, and 3 grams of protein per cup, so it’s a good option for vegans and vegetarians. It is also a good source of healthy omega-3 and omega-6 fatty acids, which your body cannot make on its own. Hemp is hardy and versatile, good for soil health, and requires few pesticides. It requires more water than oats or soybeans but far less than almond or cow’s milk.
Which milk is best?
It would be wonderful to determine which alt milk is the best one to choose, but there are so many variables in the mix with regard to carbon footprint, nutrition, personal requirements, and preference. Even within the same category of milk, production processes can vary greatly between companies so it's hard to give a clear-cut "winner," cup for cup. GO HERE to see graphs that compare the environmental impact of one glass of different types of milk, calculate how your food choices impact the environment, and see climate impact by location.
*LCA (Life Cycle Assessment): a “cradle to grave” inventory that assesses the environmental impact associated with all stages of a commercial product, process, or service)
Photo by Austin Wilcox on Unsplash