Instead of putting cow’s milk on their oatmeal in the morning, more and more people are switching to nondairy milk alternatives, such as soy, almond, and rice milk.  Is this a bad thing? Americans are drinking far less cow’s milk than we used to, even though most people know that the calcium in milk helps to build strong bones.  Let’s compare the key nutrients in milk to those in popular milk alternatives.  We’ll also look at some key health benefits they have to offer.

Calcium

Milk is best known for being an excellent source of calcium, which helps build strong bones and prevent development of bone diseases like osteoporosis.  Calcium also plays a role in cell signaling, energy metabolism, blood pressure regulation, muscle contraction, and hormonal action.¹ Unfortunately, it turns out that we are unlikely to get enough calcium if we don’t eat or drink dairy.² A small (8 oz) glass of milk provides 20-30% of the recommended dietary allowance (RDA) for calcium for people over age 3. The good news is that milk alternatives like soy, rice, and almond milk are usually fortified with calcium so they provide the same amount as a glass of milk.^3-4 Be sure to look at the ingredient list though, since some types of calcium are more easily absorbed by the body – look for calcium carbonate instead of calcium triphosphate.⁵

Other Vitamins and Minerals

Milk is a naturally good source of all kinds of nutrients besides just calcium, including potassium, phosphorus, riboflavin, and vitamin B12.³ It also contains a fair amount of magnesium, thiamin, and zinc. Most milk and milk alternatives have added vitamin D, which aids in calcium absorption, as well as vitamin A. In fact, milk is a main dietary source of vitamin D for Americans.⁶  Many milk alternatives are also fortified with additional vitamins, such as vitamin B12, so that they more closely resemble the nutrient profile of milk.  If you check out the table below, which compares milk to milk alternatives, you’ll see that they are all pretty good. After fortifying soy milk with calcium, riboflavin, and vitamin B12, it’s a close tie between cow’s milk and soy milk. However, there’s more to the story.

Protein

Just like your mom always said, milk is an excellent source of protein.  One cup of milk contains more protein than a large egg!³  Proteins help your body do important things, like build and move muscles, catalyze chemical reactions, transport molecules, repair damage, and build protection. Not all proteins are created equal, though.  Your body breaks down the protein you eat into building blocks (called amino acids) that it needs to make proteins for specific purposes (like repairing a muscle). Some amino acids can only be obtained from the diet; these are called essential amino acids. The two types of protein in milk (whey and casein) are especially good because they are complete proteins, which means that they contain all of the essential amino acids in appropriate proportions.^7-8 Proteins also vary in how easy they are for your body to absorb and use, which we refer to as their biological value. Milk’s a winner here: whey protein (which makes up about 20% of milk protein) has the highest biological value of any protein source.⁸ Of the common milk alternatives, soy milk is the only one that contains a comparable amount of protein. Soy protein is considered a complete, high quality vegetable protein, but it is lower in several essential amino acids compared to casein.⁹

Sugar and Carbohydrates

Even though it’s not notably sweet, milk contains sugar.  The naturally-occurring sugar in milk is called lactose.  It can cause problems for some people whose bodies don’t make the enzyme to break it down.  Thankfully, lactose-free milk is widely available!  Lactose-free milk, oddly enough, tastes sweeter than regular milk because the lactose has been broken down into its component parts, glucose and galactose, and glucose is sweeter.  Milk alternatives are sometimes available unsweetened; unsweetened soy and almond milks are very low in sugar. However, most commercial brands have added sugar to improve taste. Look at the ingredients list to find out if sugar has been added. Remember that terms like “syrup” and “cane juice” in the ingredients list mean that there are added sugars. Milk alternatives that contain low or no added sugar may still contain carbohydrates if they are made from beans or grains or if they have added starch.  So, there’s no clear winner when it comes to sugar and carbohydrates, but check your labels!

Fat and Cholesterol

Because cow’s milk comes from spoiler alert cows, whole milk contains saturated fat and cholesterol. Low fat or fat free milk are recommended because they contain minimal amounts. Soy, rice, and almond milks are generally low in total and saturated fat and do not contain cholesterol because they are not derived from animals. Coconut milk, another popular milk alternative, generally contains a significant amount of saturated fat, even in light versions.³  

Beyond Bone Health

Milk and the major milk alternatives offer multiple health benefits, although some are better than others. Milk has been linked to decreased blood pressure, partly due to magnesium, potassium, calcium, and peptides derived from whey and casein proteins.⁷ It also contributes to reduced cardiovascular disease risk because of its high calcium content. Calcium intake is believed to promote heart health through effects on fat absorption and metabolism.¹ Soy milk may also be good for your heart, since some studies have shown a small decrease in LDL cholesterol with soy protein intake.¹⁰ Here’s where you’ll really start paying attention, though: low fat and nonfat calcium-rich foods are believed to promote weight control due to effects of calcium on energy metabolism.¹¹ Soy milk and nonfat milk equally promoted weight loss in one study,¹² while milk had the greater effect on weight loss and waist circumference than soy milk in another study.¹³ Because of the different types of protein they contain, milk is probably better than milk alternatives at suppressing appetite and food intake.¹⁴

How Much Milk Should You Drink?

Two to three servings (cups) per day of milk, dairy, or milk alternatives are usually recommended.¹⁵  Don’t go too crazy, though, since there can indeed be too much of a good thing.  Very high intake of calcium could inhibit your body’s ability to absorb other nutrients like iron.Additionally, researchers are investigating whether there is a relationship between very high intakes of calcium, dairy, and soy and certain types of cancer.^1,10 Sticking to 2-3 servings per day will help you maximize the benefits of milk while minimizing any potential risks.

Also, despite being a healthy choice for kids and adults, milk and milk alternatives aren’t recommended for babies (babies need very specialized nutrition, so talk to your pediatrician about options for your infant).

So which milk comes out ahead? Based on our comparison, cow’s milk is still a front-runner for overall health benefits. If you have an allergy to milk, choose not to consume animal products, or simply prefer the taste, soy milk is also a great choice. While rice and almond milks are certainly healthier than many other beverage choices, their lower protein content makes them less ideal for most people.

Now, don’t you want to go drink a glass of milk?