When I became lactose intolerant earlier this year, I decided to give soy milk a try as a milk replacement. I remember walking over to the dairy section and thinking "how will I ever find the soy milk I want?" The business of milk replacements is definitely booming. There's soy milk, cashew milk, almond milk, coconut milk along with all the various flavors they come in. If you walk into the grocery store not knowing what kind to get, I don't know how you could make a decision with all those options staring you in the face.
So, let's break it down! In my opinion, milk is the best option. It's a great source of calcium and protein and is usually fortified with extra vitamin D (it does occur naturally in milk in small amounts). There are people, though, who can't drink milk; don't like to drink milk; or, for ethical reasons, won't drink milk.
For all of the following, I am comparing unsweetened substitute options to a glass of non-fat milk. All you add with all those various flavor options is sugar (sometimes up to 20g per serving). For all of these comparisons, I'm comparing with milk alternatives fortified with calcium and vitamin D.
On a nutrient basis, soy milk is closest to milk. It provides 7g of protein per serving compared to milk's 8g, and about the same amount of calcium and vitamin D. Soy milk is a healthy alternative to milk, despite what a Google search will tell you. There is a lot of misinformation about soy. While soy does have a component of it that is similar to estrogen called phytoestrogen, it has not been shown to cause an increased risk of breast cancer. Phytoestrogens are not unique to soy; they can also be found in berries, yams, rice, spinach, and wine to name a few. So don't let fear hold you back from drinking soy milk!
I'm going to group almond and cashew milk together as nut milks for our comparison, because nutritionally they are pretty similar. Both are great sources of calcium and vitamin D, providing about the same amount of vitamin D as milk and a bit more calcium. Both are very low in protein, which has always seemed counter intuitive to me as nuts are a great source of protein. Unfortunately, nut milks are mostly water. You're not going to get more than 1g per serving of protein with any of the nut milks, but as long as you're getting protein from other sources it's not something I'd worry about. (However, because it's low in protein chocolate nut milk is not a good substitute for chocolate milk or chocolate soy milk as a training recovery drink.)
Coconut milk is sometimes, but not always, fortified with calcium and vitamin D, and I've found the amount that it's fortified is inconsistent. Sometimes it provides similar amounts of calcium and vitamin D to milk, sometimes it provides less. It is also high in saturated fat, as coconut is a food high in saturated fat. In general, I'd say if you enjoy coconut milk you should enjoy it occasionally, but it is not a good substitute for milk.
For all of these milk alternatives we talked about, I would suggest double checking the nutrition label before buying to make sure the substitute is fortified with calcium and vitamin D, and isn't hiding any added sugar in the ingredient list.
Taryn is a Los Angeles based Registered Dietitian who's passionate about helping you be your healthiest you.