The number of people choosing nondairy, plant-based alternatives to cow's milk appears to be growing. So, how do these different milks compare nutritionally? Research from 2018 says that eating and drinking milk that comes from cows has been falling, with interest in alternative milks rising.
One of the main medical reasons why people choose plant-based milk products is to avoid symptoms of lactose intolerance or a cow milk protein allergy. Doctors estimate the incidence of this allergy is 2 to 5% in children under 3 years old. The incidence is lower in adults. Some people may also choose plant-based milk products because they believe they are more sustainable, ethical, or healthful options compared to cow's milk.
Almond milk is one of the most widely consumed plant-based milk variety in North America, the European Union, and Australia. Researchers have suggested that almond milk is an effective alternative for children and adults who suffer with allergies or intolerances to milk. Compared to cow's milk, almond milk has less saturated fat and more unsaturated fats. The healthful fats in almond milk may help people lose weight and keep it off. Almond milk is low in calories and protein, which may not be suitable for all people, especially children.
Some manufacturers add calcium to almond milk to better resemble the nutritional content in cow's milk. People may not be able to absorb as much of this calcium as they would from dairy, so they should be sure to consume plenty of other calcium sources, such as dark green vegetables. Almond milk is available in flavored varieties. Some of these products have added sugar to extend the shelf life and improve the flavor and texture.
Unflavored hemp beverages are also low in calories and protein compared with cow's milk. There is, however, more protein in hemp beverages than in almond milk. Hemp seeds are also high in polyunsaturated fats, similarly to almond milk. Research shows that replacing saturated fats with these more healthful fats can help lower a person's overall cholesterol.
Hemp milk will not separate in hot drinks, so people can add it to their coffee and tea. Some people may not like homemade hemp milk because of its earthy taste and chalky texture. Store-bought varieties have additional ingredients that help to mask the taste and texture.
Oat milk has a mild, creamy flavor that makes it good for cereals, hot beverages, and drinking on its own. Oat milk is not suitable for people with gluten intolerance or with celiac disease. Unflavored oat milk has the highest amount of calories and carbohydrates of plant-based milk varieties. Although the sugar is natural, oat milk is very high in carbohydrates.
Soy milk is the most common substitute for cow's milk and the first plant-based alternative to appear on the market in the United States. The 2015–2020 Dietary Guidelines for Americans suggests that people with lactose intolerance consume fortified soy beverages as an alternative to cow's milk. When people compare soy milk with almond, hemp, and oat milk, this milk alternative has the highest amount of protein per serving. As with many other plant-based milk varieties, soy milk manufacturers often add calcium and vitamin D.
Plant-based milk varieties have high levels of phytate and oxalate, which are compounds that can block the absorption of calcium. According to the 2019 review in the journal Nutrients, experiments on soy milk show that despite the presence of these compounds, calcium absorption was similar to that of cow's milk if the manufacturers fortified it with calcium carbonate.
Although soy milk has more protein than other plant-based milk products, cow's milk has higher amounts of the essential amino acids methionine, valine, leucine, and lysine. People also consume soy milk because it has isoflavones, which researchers suggest have anticancer effects. Doctors may also recommend that children under 3 years old with cow milk protein allergy avoid drinking soy milk, as they may also be allergic to soy. Farmers use a variety of pesticides when growing soybeans, so people who want to avoid pesticides may wish to choose organic brands.
My Take: Soy milk also contains phytoestrogens which can disrupt hormone receptor pathways. I recommend staying away from all but naturally fermented soy. Cow’s milk has all the contamination issues of soy and then some. Avoid it as well.
Bottom Line: If you want dairy in your diet, stick to yogurt and hard cheeses. For milk, I prefer almond, but hemp and oat milk are also good choices as well.