There’s a lot of conflicting nutritional information out there, but few foods are more controversial than milk. Many people are switching from cow milk to substitutes such as goat, soy or almond milk. But is that really necessary? Here’s what science says about the health benefits of the various forms of milk.
Believe it or not, the research suggests good old-fashioned cow milk is actually very healthy. One assessment, published in the journal Food & Nutrition Research, found that milk consumption was associated with greater muscle mass and bone density, and lower risk of type 2 diabetes, childhood obesity, stroke and cardiovascular disease.
You don’t necessarily need to drink skim milk, either. Fat is an important part of a balanced diet, and meals that contain fat make you feel fuller for longer than fat-free meals. One study suggests that the amino acids in whole milk are more easily absorbed than those in skim milk.
The downside: Many people have trouble digesting cow milk. You can take pills containing lactase — the enzyme that digests lactose — or drink milk fortified with lactase. One-tenth of people are also allergic to the cow milk protein casein. If you’re one of these people, you shouldn’t drink cow milk.
Nutritionally, goat milk is similar to cow milk, but with a higher protein content. While it’s widely seen as less allergenic, the evidence for that is debatable — it contains less casein than cow’s milk, but has similar amounts of lactose, and is highly similar overall.
One experiment, published in the journal Pediatric Allergy and Immunity, found that 25 percent of people who are allergic to cow milk are also allergic to goat milk. Another study found that percentage to be higher but added that “for the 25 percent of patients that tolerate goat’s protein, goat’s milk can be an excellent substitute in children older than 2 years old.”
Studies have found no difference between babies drinking goat milk vs. cow milk, although one study, published in the Journal of Pediatric Gastroenterology and Nutrition, did note that its protein content was more similar to human breast milk than cow milk. Another study said that unmodified goat milk should not be favored over cow milk for feeding babies due to the higher protein and lower folate (vitamin B9) content.
If you’re allergic to cow milk, goat milk is worth a try, although you may need to buy it online in powdered form. Babies under 2 years old who are allergic to cow milk should not be given goat milk products without consulting a doctor.
Almond milk lacks both casein and lactose, and almost everyone can digest it just fine. In lab tests, infants who were allergic to cow milk were shown to have no adverse reaction to almond milk.
While it’s great from an allergy standpoint, almond milk does not have a complete amino acid profile — the protein in it isn’t as healthy as that in animal milk, and it has less protein overall. It also often has added sugar; if you choose to drink it, get a sugar-free brand.
Unlike most plant protein sources, soy has a complete amino acid profile. Unfortunately, it’s not as hypoallergenic as almond milk — in the same study referenced in the previous section, 23 percent of cow milk-allergic infants showed sensitivities to soy milk.
Soy also contains phytoestrogens, which mimic the effect of natural estrogen, causing hormonal disruptions. While this isn’t a cause to completely avoid soy, it should be consumed in moderation, particularly during puberty.
Commonly used as a cooking ingredient, coconut milk is more rarely consumed as a milk substitute. Coconut milk is naturally lower in protein and higher in fat than any other form of milk, although coconut milk meant for drinking is always reduced in fat.
Due to its inferior protein content with a poor mix of amino acids, coconut milk by itself is not an adequate milk substitute. On the plus side, coconut allergies are rare and not associated with nut allergies.
Rice milk is sometimes favored by patients who have severe allergic reactions to milk and other milk substitutes. Unfortunately, it has an unfavorable nutritional profile, and replacing cow milk with rice milk has been found to lead to severe malnutrition in those with food allergies.
So Which Milk Is Best For You?
Looking at the research, cow milk still seems to be the healthiest kind of milk, provided that you can digest it without issue. That’s a big “if” though — for people who have trouble with cow milk, goat milk is worth a try.
For vegans, soy milk is the option that provides the best protein content. For those with milk allergies, almond milk is your best bet. The protein content of both soy and almond milk can be improved by mixing in a little bit of whey protein powder, providing similar protein content to cow milk, without the allergenic side effects.