Animal milk vs. plant milk?

Author: 

Micaela Karlsen, MSPH

Question: 

I have long had this quesiton about milk and would really appreciate if you could answer this. I was wondering which one is the best milk choice. Some say cow - or animal milks aren't good because too much animal protein is not healthy; others say raw unpasteurised milk is a different thing all together and cannot be compared with pasteurised, homogenised supermarket milk especially if its grass-fed and organic. Some say soya isn't good for health either - so what shall I drink? Could you rank the following choices according to purely nutritional factors, such as nutrient profile and health benefits?

  • organic raw grass-fed cow, goats and sheep milk
  • hempseed milk
  • almond milk
  • oat milk
  • hemp milk
  • rice milk
  • soy milk
  • coconut drinking milk
Which one is best? And why?
 
 

Answer: 

The question about which milk is best rests on the assumption that humans need to drink milk. The choice to drink a milk beverage is entirely a choice; it is possible to obtain all the essential nutrients (with the possible exception of B12) by eating a whole food, plant-based diet. While animal milk (from cows, goats, or sheep) carry health risks associated with all animal sources of protein, it is also not necessary to consume plant-based milk beverages. Strictly speaking, plant milk is a mildly processed food, so a 100% unprocessed diet might not include it. However, where to draw the line with processing is a personal choice - an argument can be made that cooking food is too much processing, and yet many people thrive on a cooked, plant-food diet.

The process of making plant milks varies from variety to variety, and sometimes the manufacturing of soymilk uses a little more processing (in the form of heat and/or pressure) than some of the others because most people prefer soymilk that doesn't taste like soybeans. This is not necessarily required with some of the nut milks.  

However, in general the processing is minimal and if eating a plant-based milk helps you stick with a plant-based diet in the long-term, it may really support an overall healthy diet and lifestyle.

The number one thing to check when purchasing plant milk is that it is unsweetened. Most of the vanilla or chocolate flavored varieties, and even some plain varieties, have added sugar. This might be cane sugar, fructose, sucrose, or other syrup. Be sure to read the labels, because consuming liquid calories that includes added sugar is little better than drinking soda.

To address the question about the actual nutrient content, grassfed milk is not significantly different than milk from conventionally-raised animals in terms of macronutrient composition (total fat, protein, and carbohydrate). There is limited evidence that the types of fat in grass-fed beef is superior to conventionally raised beef, but the health risks most strongly associated with cow's milk comes from the excess of animal protein in the food. This is unchanged in grass-fed animals; there is still much more protein than humans need.

In this table, we can compare the macronutrient profiles for the variety of milks listed in the question. The animal milks listed are for full-fat milks - remember that as fat is removed the protein becomes a greater part of the whole, which further increases the excess of protein. The coconut milk listed is that sold in stores as a substitute for cow's milk - not the coconut milk sold in cans as a cooking ingredient (they are not extremely dissimilar though). Sources for the nutrient composition of the animal milks were the USDA Nutrient Database. Sources for  the plant milks were the manufacturer's published nutrient content. All the plant milks here are unsweetened. Small discrepancies in % kcal may be due to rounding errors. Fat has 9kcal/g, protein and carbohydrate have 4kcal/g.

Per 1 fluid cup

Energy (kcal)

Fat (g)

--%fat

Protein (g)

--%protein

Carbohydrate (g)

--%carbohydrate

Cow's milk
152

8.11
--48

7.86
--21

11.96
--31

Sheep's milk
265

17.15
--58

14.65
--22

13.13
--20

Goat's milk
168

10.10
--54

8.69
--21

10.86
--26

Almond milk (Blue Diamond)
30 (larger rounding errors due to small volume from manufacturer)
 
2.5
--75
1
--13
2
--26
Oat milk (Pacific Foods)
130
2.5
--17
4
--12
24
--74
Hemp milk (Pacific Foods)
140
5
--32
3
--8
20
--57
Soy milk (Edensoy)
140
5
--32

11
--31

14
--40
Rice milk (RiceDream)
70
2.5
--32
0
--0
11
--63
Coconut milk (SoDelicious)
70
4.5
--58
0
--0
8
--46

If these manufacturer data are close to accurate, it appears that the oat milk has the lowest % fat and highest % carbohydrate, which means that it's nutrient profile is more closely aligned with a whole food, plant-based diet. The animal-sourced milks are animal foods, and so carry a host of risks besides the fact that they have too much protein. The other plant-based milks are quite high in fat as a % of total calories - however again, if you eat them sparingly (such as a little bit poured on oatmeal) then it probably makes little difference in the overal nutrient composition of the diet. However, if you end up having a large portion, or eating it several times a day or in several different ways, it may be worthwhile to consider which one you pick and how that may make an impact on the nutrient profile of your overall diet.