Supplements in Review

  • Protein
  • Nootropic
  • Testosterone
  • Fat Loss
  • Pre-Workout
  • Vision
  • Sleep
  • More Categories…
    • Greens
    • Energy
    • Immune
    • Stress
    • Joints
    • Post-Workout
    • Growth Hormone
    • Multi
    • Brands
  • Blog
You are here: Home / Protein / Casein Protein

Casein Protein

September 17, 2016 By Leave a Comment Last Updated: August 31, 2018

Casein offers some specialized advantages over other protein sources.

casein
Casein solidifying into curds. Image by Brian Boucheron licensed under CC by 2.0

Casein is is the predominant type of protein found in milk. Alongside whey, casein is a popular dietary supplement with a number of health benefits:

  • Maximizing muscle growth. Casein is typically considered the best protein source alongside whey for maximizing muscle hypertrophy from resistance training.
  • Blood pressure support. Casein proteins called casokinins appear to suppress an enzyme that promotes blood vessel constriction.

Table of Contents

Toggle
  • Overview
    • Types of Casein Protein
  • Casein Protein’s Beneficial Bio-Activities
    • Inhibit the ACE enzyme
  • Casein Protein’s Reputation & Proposed Benefits
  • Research
    • Human Research
  • Casein Protein Dosage
  • Supplements in Review Recommendation

Overview

Casein is the term for the predominant family of proteins found in cow’s milk, accounting for 80% of its total protein content. When milk is coagulated during the cheese-making process, casein solidifies into curds, while the liquid whey is left behind.

Casein contains a variety of proteins, with the most prominent being alpha-s1, alpha-s2,  b-casein, and k-casein. While these proteins do not have any specific effects, when ingested they break down into several peptides — molecules composed of linked amino acids — that may possess biologically-active properties.

Like other animal proteins, casein provides the body with adequate amounts of all nine essential amino acids. However, it is unique for its slow digestion and absorption, allowing casein to release amino acids at a steady rate for a prolonged period of time. This stands in contrast to “fast” protein sources such as whey that result in a rapid spike in amino acid availability.

Casein is mainly used a dietary supplement for individuals seeking to improve their protein intake for the purpose of building muscle and losing or gaining weight.

When present in milk and other liquids, casein is suspended in tiny particles known as micelles, which are made of an outer hydrophilic (attracted to water) layer and an inner hydrophobic casein layer. This unique structure is one of the main reasons why casein takes longer to digest than other proteins.
micelle-structure
Standard micelle structure. By SuperManu [GFDL], via Wikimedia Commons

Types of Casein Protein

Casein protein comes in three major powdered forms:

  • Micellar Casein. The main form of casein used in dietary/sports supplements, which maintains the structure of caseine micelles. Micellar casein products typically contain anywhere 70-90% protein.
  • Calcium Caseinate. Casein protein made from skim milk. This form is added to a variety of foods for preservation or nutrition, and is also used as an ingredient in weight gainer products.
  • Casein Hydrolysate. In this form, the casein proteins have been hydrolyzed to break them apart into constituent amino acids, which has the advantage of making it easier to absorb. This form is frequently used by clinical researchers, but is not very popular as a dietary supplement because casein is favored for its slow digestion and absorption.
The term casein derives from caseus – the Latin word for cheese.

Casein Protein’s Beneficial Bio-Activities

Aside from supporting muscle growth and weight loss or gain like all protein sources, casein may also:

Inhibit the ACE enzyme

Similar to whey protein, casein appears to contain compounds called casokinins that are capable of reducing blood pressure by blocking the activity of ACE, an enzyme that promotes the constriction of blood vessels. Studies have identified at least one of these casonikins to be casein peptide C12.1

Numerous studies have found that casein phosphopeptides are capable of protecting teeth against erosion by enhancing enamel remineralization and reducing demineralization. However, it is not clear whether this benefit can be derived from whole casein, since the active peptides may only be released during digestion.2 3

Casein Protein’s Reputation & Proposed Benefits

Similar to whey, casein is regarded as an effective source of protein for building muscle while undergoing resistance training. Although whey is certainly the more popular option among resistance training practitioners, most studies comparing whey to casein have shown no difference in the amount of muscle and strength gained.4 5

Having said that, one of ways that researchers propose casein may be superior to whey is improving muscle growth during a period of prolonged fasting, such as during sleep. In such situations, casein’s slow and steady release of amino acids could be advantageous for stimulating ongoing muscle protein synthesis and preventing muscle breakdown, since no food is being consumed.6

Indeed, as one highly-cited study reported in 1997, consuming casein resulted in a 34% decrease of whole body protein breakdown for 7 hours, whereas whey protein had no effect.

Casein can also be used to support weight loss through promoting satiety, but research in this area suggests that its cousin whey may be more effective.7 8 9

In addition, it appears that casein can be helpful for maintaining healthy blood pressure similar to whey.

A significant number of studies have shown that peptides derived from casein may have potential benefits for immunity, stress, anxiety, calcium absorption, antioxidant activity, and more. However, these results should be interpreted with caution, because as one recent review paper summarizes:

There are plenty of reports on the bioactivity of [milk] proteins and peptides in vitro. Such data, however, are insufficient in claiming an effect on human health since the active compound may be degraded during digestion, may not be absorbed or not attain the appropriate concentrations in blood and target tissues that are required for acting significantly.10

Research

Human Research

Research focusing specifically on casein is scarce; most studies compare casein to other protein sources such as whey and soy.

Casein protein may prevent muscle protein breakdown

This frequently-cited study compared the digestion of casein and whey protein. Sixteen young adults were given 30-43 g of whey or casein protein. Casein was found to result in a lower but prolonged, steady release of amino acids and similarly steady increase in muscle protein synthesis compared to whey. However the main finding was that casein resulted in a 34% inhibition of protein breakdown in the body for 7 hours after consumption, whereas whey  had no effect.

  • The researchers concluded that “the speed of amino acid absorption after protein ingestion has a major impact on the postprandial metabolic response to a single protein meal. The slowly absorbed CAS promotes postprandial protein deposition by an inhibition of protein breakdown“11

Casein may be superior to whey protein at building muscle and promoting fat loss in overweight, resistance-trained individuals

This randomized study compared the effects of a low-calorie diet plus resistance training with casein or whey protein hydrolysate. Thirty-four overweight police officers were divided into three groups for 12 weeks: diet only, diet plus resistance training plus high-protein diet using casein protein hydrolysate, or whey hydrolysate instead of casein (70-75 g protein each). The casein group had larger fat loss (8% vs 4%), lean mass gains (4% vs 2%) and strength increase of chest, shoulder, and leg muscles (59% vs 29%) than whey.

  • The researchers concluded that “hypocaloric diet, increased protein intake and resistance training resulted in a significant loss of fat mass and gain of lean mass in all  participants  compared to a hypocaloric diet alone. We also demonstrated the significant impact of a casein hydrolysate on the rate of decrease in  fat and increase in lean mass“12

Casein and whey protein may improve blood pressure and cardiovascular function in obese people

In this randomized study, 33 obese women with elevated blood pressure were supplemented daily with cabohydrate placebo, whey, or casein protein (both containing 54 g protein), or placebo for 4 weeks. They also followed an exercise regimen 3 days a week (CET).

Only the whey and casein groups saw a significant decrease of systolic blood pressure, and improvement of aortic augmentation index and arterial stiffness — two measures of cardiovascular health. This suggests that the improvements were caused by casein and whey protein alone, regardless of exercise.

  • The researchers concluded that “whey and casein supplementation combined with CET resulted  in  favorable  effects on aSBP,  wave reflection, and arterial stiffness  in young obese women with prehypertension and hypertension. Although short-term, high-intensity CET  increased muscle strength, it did not have additional beneficial effects on BP and arterial function“13

Casein Protein Dosage

  • Successful studies of casein have used doses containing 30-75 g protein
  • Casein supplements typically provide 20 – 30 g protein per scoop depending on the brand, taken daily to reach your specific protein intake goals
  • For sedentary individuals, 0.8 g/kg protein body weight is recommended
  • For resistance training practitioners, it’s best to take 20 g or more of casein before sleep or between meals, with an overall target of 1.2- 1.5 g/kg protein intake

Supplements in Review Recommendation

  • Micellar casein containing 20 g protein daily.

Casein seems to be the best source of protein alongside whey for building muscle. Casein appears to be just as effective as whey at promoting muscle hypertrophy, and may have a slight specialized advantage for muscle protein synthesis during prolonged fasting (such as when you’re sleeping).

Most casein supplements provide around 20 g protein per scoop. While the ideal dosage will vary person to person, one scoop of a casein supplement taken daily to support your protein intake for general health or resistance training is a good starting point.

References

Show 13 footnotes

  1. Townsend RR et al. A randomized, double-blind, placebo-controlled trial of casein protein hydrolysate (C12 peptide) in human essential hypertension. Am J Hypertens. 2004 Nov;17(11 Pt 1):1056-8. ↩
  2. White AJ et al. Inhibition of dental erosion by casein and casein-derived proteins. Caries Res. 2011;45(1):13-20. ↩
  3. Vashisht R et al. Remineralization of early enamel lesions using casein phosphopeptide amorphous calcium Phosphate: An ex-vivo study. Contemp Clin Dent. 2010 Oct-Dec; 1(4): 210–213. ↩
  4. Wilborn CD et al. The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes. J Sports Sci Med. 2013 Mar; 12(1): 74–79. ↩
  5. Tipton KD et al. Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise. Med Sci Sports Exerc. 2004 Dec;36(12):2073-81. ↩
  6. Hulmi JJ et al. Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein. Nutr Metab (Lond). 2010 Jun 17;7:51 ↩
  7. Hall WL et al. Casein and whey exert different effects on plasma amino acid profiles, gastrointestinal hormone secretion and appetite. Br J Nutr. 2003 Feb;89(2):239-48. ↩
  8. Veldhorst MA et al. Dose-dependent satiating effect of whey relative to casein or soy. Physiol Behav. 2009 Mar 23;96(4-5):675-82. ↩
  9. Bendtsen LQ et al. Effects of hydrolysed casein, intact casein and intact whey protein on energy expenditure and appetite regulation: a randomised, controlled, cross-over study. Br J Nutr. 2014 Oct 28;112(8):1412-22. ↩
  10. Möller NP et al. Bioactive peptides and proteins from foods: indication for health effects. Eur J Nutr. 2008 Jun;47(4):171-82. ↩
  11. Boirie Y et al.  Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A. 1997 Dec 23; 94(26): 14930–14935. ↩
  12. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab. 2000;44(1):21-9. ↩
  13. Figueroa A et al. Effects of milk proteins and combined exercise training on aortic hemodynamics and arterial stiffness in young obese women with high blood pressure. Am J Hypertens. 2014 Mar;27(3):338-44. ↩

Filed Under: Protein

Leave a Reply

Your email address will not be published. Required fields are marked *

Protein Resources

pearl-harbor-80388_1280

Protein Supplements Guide

the whey protein

Protein Supplements List

Find us on Facebook

Supplements in Review

Recently Added in “Protein”

pisum sativum protein

Soy Protein vs. Pea Protein

Soy Protein vs. Whey Protein

1024px-Harvested_seeds_of_homegrown_Chenopodium_quinoa

Quinoa Protein

1024px-1bkv_collagen_03

Collagen Protein

Seed_of_chia_(Salvia_hispanica)Salvia_hispanica_group

Chia Protein

More Posts from this Category

  • Amazon
  • Facebook
  • Instagram
  • LinkedIn
  • Twitter

Press contact information

valentino@supplementsinreview.com

info@supplementsinreview.com

Disclaimer

* These statements have not been evaluated by the Food and Drug Administration. The products mentioned anywhere on Supplements in Review are not intended to diagnose, treat, cure or prevent any disease. All information presented here is not meant as a substitute for or alternative to information from health care practitioners. Please consult your health care professional about potential interactions or other possible complications before using any product.

Copyright © 2025 · Supplements in Review · Contact Us · Disclaimer

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.Ok