Protein synthesis for bodybuilder and muscles

By Dwayne Jackson, PhD, and Jim Stoppani, PhD

Many people consider whey to be the hands-down, gram-for-gram winner in the world of protein powders. Quick digestion, high branched-chain amino acid content, great effects on protein synthesis – it’s hard to debate the billing. But unlike boxing managers who duck some fighters for fear of an upset, we’re not afraid of a little competition. As such, we’re tossing all four of the top proteins into the ring for a no-holds-barred, fact-by-fact fight for the ages.

You, the huddled masses yearning to be ripped, crave an authoritative protein champ. Like fight fans, you probably have your loyalties. Some of the old troops who long for the days of Ali and Frazier might still be clinging to egg white protein for their fix. Others might be fond of the new-school science that favors casein, whose steady Oscar de la Hoya-like reliability has been enough to fortify their physiques. And then there are those of you who are starting to root for the underdog. Despite its less-than-impressive ring record, soy – like a surging contender – is a protein on the rise and has scored some impressive victories of late. But like the great Marciano, whey’s dominance in this division of sports nutrition has been unrivaled…until now.

This fight will be decided in 10 rounds, or categories, each with a separate but distinct focus that goes to the heart of protein effectiveness. Unlike boxing’s 10-point must system, however, we’re going for golf scoring – low score wins. The winner of each round is awarded one point, second place gets two, third gets three and, if you’re still following, fourth gets four. Well’s tally the points from each category, and the protein with the fewest points will be crowned the 2007 M&F Protein Powder Champion. If all the challengers are ready, it’s time to touch gloves and fight it out. You wanna ring the bell?

ROUND 1

AMINO ACID CONTENT
A complete protein is composed of 20 different amino acids, and some of those are more critical than others. At the top of that list are the branched-chain amino acids (BCAAs) that include leucine, isoleucine and valine, which are musts for protein synthesis, the process by which muscle fibers grow. Arginine is crucial for stimulating production of nitric oxide (NO), which has numerous vital properties for muscle growth, such as increasing blood flow to muscles to deliver more nutrients, anabolic hormones and oxygen for better recovery and greater muscle protein synthesis. Glutamine is also high on the list because, along with a multitude of other benefits, it keeps muscle protein synthesis high an muscle protein breakdown low. In a hard-fought opening round for amino acid content supremacy, check out the tally at right:

SCORECARD

NO. 1	WHEY:	Due to its higher content of BCAAs – particularly leucine, the most critical amino for stimulating protein synthesis – whey is the clear winner in this opening round.
NO. 2	SOY:	The highest of the four in arginine content, and second to whey and casein in leucine and glutamine contents, respectively, soy comes in second.
NO. 3	CASEIN:	The highest in glutamine, casein comes in third. It’ll have to put up a stronger fight moving forward if it expects to stay in the hunt.
NO. 4	EGG WHITE:	Although egg white has a great overall amino acid mix, it’s highest in none of the most critical amino acids but is second to soy in arginine.

ROUND 2

BIOAVAILABILITY
The true test of a protein is bioavailability – how much of its critical aminos actually make it to the muscles. To measure this, scientists use the protein digestibility corrected amino acid score (PDCAAS). It takes into consideration the amino acid content of the protein and its digestibility, which ensures the aminos get to muscles. Proteins that meet the amino acid and digestibility requirements for humans get a PDCAAS of 100% All four proteins featured here meet the requirements for humans. In other words, they’re high-quality protein sources unlike, say, black beans, which get an 84%. Here’s how the battle of bioavailability shakes out:

SCORECARD

NO. 1

(TIE) Whey, Casein, Soy and Egg White:

The PDCAAS of each protein is 100%.

ROUND 3

HEALTH BENEFITS
For builders, the No. 1 reason to use protein powders is to boost muscle growth. But you may be surprised to find that some of the proteins have multiple health benefits. Time for the underdog to flash its health assets:

SCORECARD

NO. 1	SOY:	Soy reigns in the top spot here in the third. Not only does it protect against cardiovascular disease, but the FDA-approved health claim for 25 grams of soy protein daily reduces the risk. Soy is also beneficial in protecting against numerous cancers such as colorectal, breast and prostate.
NO. 2	WHEY:	Although the extra health benefits of soy may not get some bodybuilders to use it more often, many guys will be happy to know that the whey protein they love for mass-gaining also does a body good. For starters, because it comes from milk, it’s a good source of calcium, which enhances bone and dental health as well as aids fat loss. Whey was also recently found to reduce the risk of cardiovascular disease via its ability to lower blood pressure and increase blood vessel dilation, which has muscle-building effects. In addition, whey enhances the body’s levels of a critical antioxidant known as glutathione and may even help ward off certain cancers. Whey protein also lowers LDL (bad cholesterol) levels.
NO. 3	CASEIN:	Similar to whey, casein contains beneficial peptides that help lower blood pressure; it’s also a good source of calcium. Not bad, but not enough to climb ahead on the scorecards.
NO. 4	EGG WHITE:	There’s little research on the specific health benefits of egg white protein, putting it in last here.

ROUND 4

PUSHING PROTEIN SYNTHESIS
Protein builds muscle by increasing the process of protein synthesis. Therefore, bodybuilders should be taking protein powders that maximize protein synthesis. During a protein synthesis-heavy fourth round, here’s how the challengers stack up:

SCORECARD

NO. 1	WHEY:	The landmark 1997 French study from the Universite Clermont Auvergne reported that due to whey’s rapid digestion, it leads to proteins weren’t directly compared, it can be assumed that since they aren’t as rapidly digested AS WHEY, THEY DON’T STIMULATE PROTEIN SYNTHESIS AS SIGNIFICANTLY.
NO. 2	SOY:	There’s some controversy over soy’s effectiveness in stimulating protein synthesis and therefore muscle growth, but in this round soy played to is strengths. Research on both bodybuilders and rats has shown soy is about as effective as whey at stimulating muscle growth. Yet research also shows that due to the slightly lower BCAA content of soy compared to whey, soy doesn’t activate critical factors involved in protein synthesis as well as whey does.
NO. 3	CASEIN:	although casein was shown to be less effective at stimulating protein synthesis at rest in the 1997 French study, more recent research from the University of Texas Medical Branch (Galveston) reports that casein may be just as effective at stimulating protein synthesis postworkout as whey.
NO. 4	EGG WHITE:	Research shows that egg white protein has similar effects on stimulating protein synthesis as milk protein in certain populations. Although it has a decent amount of BCAA content, its ability to drive protein synthesis isn’t as effective as that of whey.

ROUND 5

STOPPING MUSCLE BREAKDOWN
A protein’s ability to stifle muscle protein breakdown is very important. That’s because muscle growth is the result of the delicate balance between protein synthesis and protein breakdown. The more synthesis and less breakdown you have, the more muscle growth you’ll experience. Here’s how the four proteins stack up for limiting muscle protein breakdown:

SCORECARD

NO. 1	CASEIN:	The French study mentioned in Round 4 also discovered that casein was superior at blunting muscle protein breakdown. This is due to its slow and steady rate of digestion, which means it delivers a continuous supply of aminos to muscle cells. Because of this, casein comes in at No 1 here.
NO. 2	EGG WHITE:	The digestion rate of egg white protein isn’t quite as slow as casein’s, but it’s also not nearly as fast as those of whey or soy. This likely leads to egg white’s ability to effectively prevent muscle protein breakdown almost as well as casein as shown in clinical trials.
NO. 3	SOY:	Soy protein digests almost as rapidly as whey, which means its ability to halt muscle protein breakdown is limited.
NO. 4	WHEY:	As effective as it is at boosting protein synthesis, shey has little effect on halting muscle protein breakdown, bringing it in at No. 4.

ROUND 6

PREWORKOUT PERFECTION
Research shows that the most critical times to take protein powders are immediately before and after workouts. The which one at which time? Here’s how they compare as preworkout supplements:

SCORECARD

NO. 1	WHEY:	Whey protein contains components that enhance dilation of blood vessels, which promotes the delivery of nutrients (such as the amino acids it supplies), hormones and oxygen to muscles during exercise. Due to its rapid digestion rate and impact on blood flow, its aminos are quickly available to enhance muscle protein synthesis. Research from the University of Texas Medical Branch (Galveston) shows that rapid delivery of amino acids to muscles immediately before workouts maximizes muscle protein synthesis. This brings whey in at No.1.
NO. 2	SOY:	Soy is beginning to show signs of improvement here in the sixth. Because it has a high amount of arginine (almost 2 grams per 20 grams of soy), it makes a great NO levels and enhancing dilation of blood vessels. Plus it’s digested almost as rapidly as whey protein.
NO. 3	EGG WHITE:	Egg protein is second to soy in arginine content, meaning that it can also help enhance blood flow to muscles via greater dilation.
NO. 4	CASEIN:	Last, but certainly not least, casein is slowly digested, which means it won’t get a boatload of aminos to your muscles fast. It will, however, supply a steady flow that can help stave off muscle breakdown during a workout. It comes in at No. 4 here, but it’s still a valuable protein for a preworkout mix.

Source:MUSCLE & FITNESS