Diet and Nutrition

Supplement Staples for 2009 – Protein is Prime

Now that the Holiday Season is over and the New Year is upon us, it is a perfect time to re-examine your supplement plan for 2009. With thousands of different dietary supplements available, it quickly becomes an overwhelming task to make sense of product claims and separate fact from fiction.

The first order of business is to make sure you have the basics covered. There is a sizeable amount of scientific literature supporting the anabolic effects of creatine and the general health benefits of fish oil.

While I’m a major advocate for including these as staples for any serious athlete, I think the number one supplement you need in your arsenal is protein. Regardless of your specific goals or whether you are a novice or veteran in the gym, a high quality protein supplement is essential for maximizing training adaptations. 
 
The Most Important Reason You Need Protein

If you don’t consume protein around your workout, protein balance is negative. In the fasted state, it is true that resistance exercise alone has an anabolic effect by increasing protein synthesis proportionally more than breakdown, but the end result is still a negative protein balance. That simple fact is the main reason you need to consider a protein supplement as part of your nutritional supplement program.  Simply put, the amino acids provided by protein serve as the building blocks for building muscle proteins. If you do not provide the amino acids in your diet, the body breaks down its own muscle proteins to provide the amino acids needed.

Three Key Questions

When it comes to protein supplements, there are a large number of products to choose from. From a practical standpoint, there are 3 main questions to address with protein supplementation:

  1. What source of protein should be used?
  2. How much protein should be ingested?
  3. When should protein be consumed?

Be skeptical if anyone claims to have unequivocal answers to these questions because the science is far from absolute.  We have some very good knowledge about protein supplementation, but there are still many gaps that need to be addressed. The results from studies can, however, begin to point us in a direction that makes the most sense.  When looking at the preponderance of evidence a sensible case can be made for providing recommendations on protein supplementation.
 
1. What source of Protein should be used?

Two of the most popular protein sources are whey and casein, the two major milk proteins.  Both are excellent sources of all the essential amino acids, but they have some key differences.

Whey is renowned for its high quality rating and is definitively the most popular supplemental protein. Scientific studies have revealed that whey has several unique qualities that make it an attractive protein source for athletes:

  • A distinguishing feature of whey protein is its high prevalence of essential amino acids.
  • Whey contains about 10% leucine which directly activates a critical compound in muscle cells called the mammalian target of rapamycin (mTOR).  mTOR activates protein synthesis. 
  • Whey protein is digested and absorbed quickly resulting in a rapid increase in plasma amino acids.  This results in a large and rapid increase in protein synthesis.
  • Chronic ingestion of whey results in improved body composition including both increased lean body mass and decreased fat mass.
  • Whey is helpful in weight management due to increased satiety and increased energy expenditure.
  • Whey protein consumed after resistance exercise provides a greater overall anabolic effect on skeletal muscle.
  • Whey protein improves blood glucose control.
  • Whey protein has antioxidant effects due to the fact it is a unique and rich source of cysteine and thiol groups (3-4 times higher than soy).  These groups are rate-limiting for synthesis of glutathione (GSH), one of the most important non-enzymatic antioxidant defense systems.
  • Whey fractions such as lactoferrin, glutamine, immunoglobulins, and other peptides (eg, lysozome, -b-lactoglobulin, and b-lactalbumin) may have positive effects on immune function.
    • Several peptides from whey protein have been shown to possess hypotensive properties, and some studies show lowering of  blood pressure on par with some drugs.

Casein also has several unique characteristics worth noting. Casein is the most abundant protein in milk. It has all the essential amino acids and scores high on all methods of protein quality. Whereas whey protein is more soluble in an acid environment, casein is relatively insoluble. Because casein is insoluble it tends to form structures called micelles. Micelles are suspensions of spherical structures that increase solubility in water.  Casein’s insolubility slows its digestion rate. In contrast to the rapid digestion and release of amino acids into the blood after ingestion of whey, the slow digestion of casein in the stomach results in a prolonged and steady release of amino acids. The effects of this pattern of slow release have been investigated in a number of studies.  For strength trainees, one very important effect is the promotion of an anti-catabolic environment.

An early (considered classic) study documenting the effects of casein on protein metabolism was done by French researchers and published in the prestigious Proceedings of the National Academy of Sciences(1). Healthy subjects ingested 30 g of either whey or casein and anabolic and catabolic effects were measured for 7 hours after consumption. Whey protein resulted in a rapid increase in blood amino acids and protein synthesis, but it was short-lived. Casein, on the other hand, resulted in a prolonged increase in blood amino acids and a 34% reduction in protein breakdown. The net protein balance remained more positive for casein over a 7 hour period. The authors attributed this to casein’s delayed gastric emptying and slower absorption rate from the gastrointestinal tract. These findings were quite revolutionary.  In fact, a commentary was written in the top science journal in the world, Nature(2).

To gain further insight into these phenomena, researchers performed additional experiments to document the effects of protein digestion rate on protein turnover. In one study(3), healthy young men were provided one of four meals: 1) a single meal composed of 30 g of casein, 2) a single meal containing 30 g of individual amino acids equal to the casein meal, 3) a single meal composed of 30 g of whey, and 4) 30 g of whey provided in a sequence of 13 small meals given each 20 min.  In this case, Meal 1 and Meal 2 were essentially both casein, but varied in digestion rate. Meal 3 was whey which is a fast-digesting protein. Meal 4 was whey, but the repeated ingestion mimicked the characteristics of a slow digestion protein like casein. The results supported the importance of digestion rate on protein turnover. Meal 2 (free amino acids) and Meal 3 (whey), both fast-digesting meals, resulted in a larger increase in protein synthesis, but it was transient. They also resulted in a large transient increase in protein oxidation. Meal 1 (casein) and Meal 4 (repeated small whey feedings), both effectively slow-digesting meals, resulted in a smaller effect on protein synthesis, but prevented protein oxidation and strongly inhibited protein breakdown. Protein balance over the 7 hour period of measurements was significantly higher with the slow-digesting meals. Thus, casein, or small whey “meals” consumed repeatedly resulted in the most favorable protein balance over a sustained period.

These studies show unequivocally that digestion rate is an independent regulator of protein retention. Therefore, casein makes an ideal protein supplement to sustain long periods of an anabolic environment for muscle growth.

Since whey rapidly increases protein synthesis, and casein blocks protein breakdown, a combination of both proteins makes intuitive sense. A recent study (4) compared the effects of supplementing with either a combination of whey and casein, or carbohydrate on several markers of muscle anabolism during strength training. Untrained men participated in a 10 wk resistance training program and either supplemented with 40 g of carbohydrate or 40 g of protein (containing a mixture of whey and casein). Half of the respective supplements were consumed one hour before and immediately after exercise on workout days. The results were overwhelmingly positive for the combination protein group. Despite similar background diets and identical training programs, supplementation with protein resulted in greater increases in several measures of muscle anabolism including greater increases in lean body mass, thigh muscle mass, muscle strength, anabolic hormones, and muscle specific proteins.

In a similar study(5) that lasted 14 weeks, untrained men performed resistance training and received either 25 g of carbohydrate, or 25 g of a combination protein (whey and casein) 1 hr before and immediately after exercise. The combination protein group resulted in significantly greater increases in muscle fiber size compared to the carbohydrate group. These studies provide strong evidence that a combination protein consumed before and after workouts augments muscle anabolism.

These studies support the general concept that combining whey and casein has an anabolic effect, but the control groups consumed carbohydrate, so it is unclear if the combined effects would be better than the individual protein sources. Few studies have directly compared whey versus casein, or a combination of whey and casein versus each alone on the adaptations to resistance training. One study does, however, provide evidence supporting the theory that a combined whey and casein supplement is superior. This study showed that a group of men who received a protein supplement consisting of both whey and casein had greater increases in lean body mass after 10 weeks of training compared to a group that received only whey protein(6).

2. How much protein should be ingested?

Many of the early studies showing that protein supplementation after resistance exercise augmented protein synthesis used only 6 grams of essential amino acids, thus you get a pretty good bang for your buck.  However, few studies have addressed whether providing more is better. Prominent protein researchers addressed this void in the literature by conducting a dose response study in healthy active men(7). The protocol involved subjects performing a resistance exercise session on five separate occasions. After exercise, they randomly consumed a drink containing different doses of protein: 0, 5, 10, 20, or 40 grams. The source of protein was egg. Compared to consuming no protein, muscle protein synthesis was increased by 37% after the 5 g dose and 56% after the 10 g dose of protein. The 20 g dose condition increased protein synthesis even further by 97%. When 40 g of egg protein was ingested, there was no further increase in protein synthesis.

These results indicate an efficacious dose response relationship between the amount of protein ingested and stimulation of protein synthesis after resistance exercise up to 20 grams of dietary protein. At the higher dose, there was a marked increase in protein oxidation suggesting that the extra protein was being used as fuel. This is a milestone study that shows 20 grams of high quality protein providing about 9 grams of essential amino acids is a sound dose to consume after resistance exercise.

3. When should protein be consumed?

When it comes to protein supplementation, the what and how much are critical, but new research indicates so is the when. The majority of protein supplementation studies have focused on the post-exercise time period and this work unequivocally shows it is an important time. However, there is accumulating evidence that the pre-exercise time period is important as well. The main evidence for this comes from a study where researchers gave subjects 6 grams of essential amino acids after exercise and showed it stimulated protein synthesis(8). This was a well characterized response at the time. The surprising finding from the study was that when the same dose of protein was given immediately before exercise, there was a significantly greater increase in protein synthesis after exercise. The greater effect associated with pre-exercise supplementation was attributed to elevated blood levels of amino acids before exercise and greater delivery of those amino acids to the active muscles as a result of muscle contraction. It has been shown that delivery of amino acids to muscle is one of the rate limiting steps in protein synthesis. This landmark study makes a strong case for consuming protein during the pre-exercise time period.

A follow up study by this group examined whether the timing of whey protein supplementation was important in terms of promoting anabolism(9). Healthy subjects were placed into a group that received 20 g of whey immediately before, or a group that received the same dose immediately after a bout of resistance exercise. The anabolic response (muscle protein balance) was increased in both groups, but was similar, indicating that timing (relative to before or after training) of whey protein supplementation was not a factor. The reason for the lack of a greater response with pre-exercise consumption like the previous work is unclear, but could be due to the difference in protein sources (intact whey versus free amino acids). The researchers did not have a group who consumed protein at both time points (both pre and post-exercise). The important point to gleam from the research is that consuming protein either immediately before, or immediately after resistance training increased protein synthesis, so a reasonable inference is that consuming protein at both times would be of equal or potentially greater benefit than either or. 

Summary

The science clearly shows that protein supplementation around a workout is crucial in order to switch from a negative to a positive protein balance.  While there are many high quality protein sources available, whey and casein are two of the most popular and each have unique features with favorable qualities.  Whey is quickly digested with rapid and transient anabolic effects, whereas casein is slowly digested with prolonged anti-catabolic effects and superior net retention. Combining whey and casein thus makes intuitive sense and there is evidence such an approach may be better than using either alone for augmenting adaptations to training. The ideal amount of protein that increases protein synthesis without sharply increasing protein oxidation appears to be somewhere around 20 grams per serving. Finally, there is evidence that both the pre-exercise and post-exercise time periods are important for increasing protein balance.  If you are seeking a high quality blend of both whey and casein proteins, AtLarge Nutrition’s Nitrean provides a nearly ideal blend with the added benefit of egg protein. 

Written by Jeff Volek, PhD, RD

Wannabebig’s Protein Powder Supplement recommendation Nitrean is one of the premier protein products on the market today. It is superior to any whey-only powder with its blend of whey (isolates, concentrate, and hydrolyzed), casein, and egg proteins.

In addition, it is one of the best mixing and tasting products available.Men’s Health have recommended Nitrean Protein numerous times and most recently as their top choice for the protein supplement category in their 2008 awards.

Discuss, comment or ask a question

If you have a comment, question or would like to discuss anything raised in this article, please do so in the following discussion thread on the Wannabebig Forums – Supplement Staples for 2009 – Protein is Prime discussion thread.

References

1. Boirie, Y., Dangin, M., Gachon, P., Vasson, M. P., Maubois, J. L. & Beaufrere, B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A. (1997); 94:14930-14935.

2. Fruhbeck, G. Protein metabolism. Slow and fast dietary proteins. Nature. (1998); 391:843, 845.

3. Dangin, M., Boirie, Y., Garcia-Rodenas, C., Gachon, P., Fauquant, J., Callier, P., Ballevre, O. & Beaufrere, B. The digestion rate of protein is an independent regulating factor of postprandial protein retention. Am J Physiol Endocrinol Metab. (2001); 280:E340-348.

4. Willoughby, D. S., Stout, J. R. & Wilborn, C. D. Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength. Amino Acids. (2006).

5. Andersen, L. L., Tufekovic, G., Zebis, M. K., Crameri, R. M., Verlaan, G., Kjaer, M., Suetta, C., Magnusson, P. & Aagaard, P. The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength. Metabolism. (2005); 54:151-156.

6. Kerksick, C. M., Rasmussen, C. J., Lancaster, S. L., Magu, B., Smith, P., Melton, C., Greenwood, M., Almada, A. L., Earnest, C. P. & Kreider, R. B. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. (2006); 20:643-653.

7. Moore, D. R., Robinson, M. J., Fry, J. L., Tang, J. E., Glover, E. I., Wilkinson, S. B., Prior, T., Tarnopolsky, M. A. & Phillips, S. M. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr. (2008).

8. Tipton, K. D., Rasmussen, B. B., Miller, S. L., Wolf, S. E., Owens-Stovall, S. K., Petrini, B. E. & Wolfe, R. R. Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am J Physiol Endocrinol Metab. (2001); 281:E197-206.

9. Tipton, K. D., Elliott, T. A., Cree, M. G., Aarsland, A. A., Sanford, A. P. & Wolfe, R. R. Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise. Am J Physiol Endocrinol Metab. (2007); 292:E71-76.