Dairy vs Plant Protein
Article by Stefan Burns - Updated January 2022. Join the Wild Free Organic email newsletter!
There are many different types of protein found in nature, but for protein supplements the divide begins at whether the protein is animal or plant based. A protein molecule is made from a long chain of amino acids, and each type of protein has a unique sequence of amino acids. Therefore, the protein chains found in broccoli differ from those found in eggs. As science had discovered the different types of protein, we have started to learn the chemical differences between different types of plant and animal proteins and how they affect the body differently. Proteins differ in their effects on muscle protein synthesis, level of satiety, and immune system response.
For both athletes looking to improve their performance or regular folks trying to look better and live healthier, protein is an important macronutrient to understand and to know how to utilize. The general recommendation for protein intake is 2 grams/kg body-weight, or 1 gram/lb. For a 70 kg (155 lb) individual, that means they should aim to consume 140-155 grams of protein daily for optimal body composition and maximum wellness benefits.
It can be difficult to achieve that target consistently solely from whole and unprocessed foods, especially if you follow a lower protein vegetarian or vegan diet, and protein supplements like shakes and bars can help you meet your daily protein goals. For decades the only protein supplements were dairy based, specifically casein and whey protein, but now plant proteins are more and more popular. Uncommonly used supplemental protein sources like beef and egg proteins will not be discussed. Below we examine the pros and cons of dairy and plant-based proteins so you can understand how to best use either protein source when appropriate.
Dairy Proteins
Dairy-based proteins, typically derived from cows milk, can be separated into casein and whey proteins. Before whey and casein are separated, they are known as "milk protein", and that's the type of protein Orgain uses in their Grass-Fed Clean Protein Shake (as pictured).
PROS:
Milk proteins are extremely bioavailable (1), easily absorbed from food sources and then efficiently incorporated into the proteins of an organism's body.
Milk proteins contain abundant Branched-Chain Amino Acids (BCAA's) (2), the main amino acids responsible for stimulating an increase in muscle protein synthesis (MPS). With all other factors equal, more MPS, more muscle!
Milk proteins are widely available! Due to the size of the dairy industry, milk, casein, and whey protein can all be had at a relatively inexpensive cost, with different levels of quality from concentrates to hydrolysates all having different price points.
CONS:
Any food can be allergenic, but dairy-based foods are the most common food allergy (3), and should be strictly avoided if you have a dairy allergy. Likewise, those with a lactose intolerance should steer clear, even from products from like whey isolate which contain virtually zero lactose.
Dairy protein products are derived from animals and for vegans and vegetarians looking to reduce their animal product consumption, plant proteins are a lower impact alternatives.
Plant Proteins
Plant-based proteins, once a niche product, have dramatically increased in popularity recently. Soy protein, once the plant protein of choice, has recently taken the backseat to newer options such as pea, pumpkin seed, and hemp proteins. The Vega protein drink pictured contains those three plant-based proteins.
PROS:
Plant proteins are not commonly allergic, with soy protein being the exception (4), and in my experience, it's harder to develop an intolerance to plant-based proteins. For those with sensitive guts and damaged intestinal tight junctions, plant proteins are a better choice until gut health is restored.
While plant proteins typically contain less protein per gram of product, they also contain more fiber! As it has been shown, fiber is one of the most important variables which determines the satiation value of a food (5), and a plant-based protein drink will stave off hunger longer than a dairy alternative.
Vegan friendly!
CONS:
Plant proteins, due to their structural makeup, don't have as pleasing of a texture or taste as dairy derived proteins, and often protein manufacturers add extra sugar, emulsifiers, and stabilizers to plant protein products to make them more palatable.
Plant proteins aren't as efficiently absorbed as dairy protein, having lower biological values. This means that you'll need to consume more plant protein than dairy protein to ensure you receive an adequate amount of protein for your desired goals.
Protein Recommendations
To simplify, there are two reasons you would consider buying a protein powder or drink.
Your goal is to build muscle and improve body composition as quickly and efficiently as possible.
Your want to improve protein intake for overall health and wellness inspirations.
If your goal is #1, and you are not lactose intolerant, then a hydrolyzed whey protein will be the best protein supplement for your goals. Whey hydrolysate empties out of the stomach faster, is absorbed faster, increases muscle protein synthesis the most, and creates the biggest insulin response. Hydrolyzed whey protein is the most anabolic form for protein known. Whey hydrolysate should not be used by those with blood sugar problems.
If your goal is #2, then a plant-based protein is recommended. Soy protein is not recommended because it is allergenic, contains high levels of phytoestrogens, and doesn’t stimulate muscle protein synthesis well. Pea, pumpkin, and hemp seed proteins are recommended instead. These proteins, used individually or together act as a complete protein source, digest easily, stimulate muscle protein synthesis, and come paired with plant fiber.
The best protein source though is from whole unprocessed foods. Protein supplements are a means to an end, not the end destination. Protein drinks should not be your main source of protein. Having a protein drink occasionally is OKAY, but consistent protein drink use is overall more less healthy than eating whole nutritious foods.
References:
Hoffman JR, Falvo MJ. Protein - Which is Best?. J Sports Sci Med. 2004;3(3):118-30.
Rafiq S, Huma N, Pasha I, Sameen A, Mukhtar O, Khan MI. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species. Asian-australas J Anim Sci. 2016;29(7):1022-8.
Milk Allergy Vs. Lactose Intolerance. Food Allergy and Research Education.
Soy Allergy. Food Allergy and Research Education.
J. Slavin, and H. Green. Dietary fibre and satiety. British Nutrition Foundation.