Optimum Nutrition Products Articles & Resources

Casein This is the major protein component of milk (about 80%) and it exists as micelles (globules). There are three major caseins--alpha, beta and kappa--that differ by their size. These caseins are easily digested and are often isolated for cheese production. Casein is a slower-absorbed protein that provides a steady trickle of amino acids to muscle cells for several hours, helping inhibit muscle-protein breakdown.

Whey The other major part of milk protein is whey (about 20%). Unlike casein, whey proteins are soluble in liquid and have many different benefits besides muscle growth. Whey is a fast-digesting protein with a high branched-chain amino acid (BCAA) content that quickly delivers these BCAAs to muscle cells. Due to its fast action and its high BCAA content, whey protein is an excellent choice to take immediately before and after your workouts.

Here's a list of some significant whey proteins and their important properties.

* Beta-lactoglobulin The largest protein fraction of whey, it's rich in BCAAs.

* Alpha-lactalbumin A low-molecular-weight peptide fraction of whey that is easily digested, allowing faster absorption and uptake by muscles.

* Glycomacropeptide Actually a fraction of casein that is often found in whey, it stimulates the release of CCK--a hormone that signals to the brain that you are full--which helps to reduce appetite.

* Immunoglobulins Fractions of whey that strengthen the immune system.

* Bovine serum albumin peptides The fractions of whey that are rich in the precursors for glutathione (one of the body's most important antioxidants).

* Lactoferrin and lactoperoxidase Minor protein fractions that have antimicrobial properties.

UNDERSTAND YOUR PROTEIN PRODUCT One of the biggest challenges for you as a bodybuilder is understanding what you're buying. Here's a glossary to let you know what's in a product. These are the phrases that you'll find on the ingredients label of protein supplements. Remember that ingredients on labels are listed in order of concentration.

* Whole milk protein (WMP) Made by filtration of whole milk to remove much of the carbs and fat. This process leaves the biologically valuable fractions that help promote a healthy immune system and aid the recovery from strenuous exercise.

* Milk protein concentrate (MPC) This has a protein content around 80% and contains both the whey and the casein fractions of milk. Typically, it's very low (around 5%) in lactose content. Ultrafiltration, the preferred method used to produce MPC, employs varying degrees of pressure to force the liquid portion of the milk through a porous membrane that only allows water, minerals and organic molecules to pass through. The bigger protein molecules cannot pass and are collected from the membrane for further processing that results in a powdered protein. Because it provides both fast- (whey) and slow-digesting (casein) protein, MPC is a good choice any time of day, especially between meals and before bed.

* Milk protein isolate (MPI) Made by precipitating whey proteins and casein from skim milk. The MPI is then washed to remove impurities, providing greater than 85% protein and virtually no lactose or fat.

* Whey protein concentrate (WPC) The most basic of the whey proteins, this high-quality complete protein contains some carbohydrates and fats. It can vary from 30-85% protein, although most products today fall within the 70-80% range, depending on the amount of filtering that is performed on the whey. The filtration process typically involves ultrafiltration, diafiltration and, sometimes, microfiltration, which usually leave much of the vital fractions in place.

* Whey protein isolate (WPI) A purer form of whey protein (90% or higher) than concentrate, because it is processed even further via longer filtering or ion exchange (IE). This makes it a good protein to use when dieting because it has a lower carbohydrate and fat content. However, IE WPI will have lower amounts of glycomacropeptide (the CCK trigger that helps stem appetite).

* Whey protein hydrolysate (WPH) WPH is produced when WPI is taken through one more step--hydrolysis. All whey proteins tend to be absorbed rather quickly, but WPH is absorbed the fastest of the whey proteins, making it a good choice for intraworkout or postworkout consumption. Depending on the manufacturing process, WPH can have a range of 3-50% hydrolyzed protein. A main drawback to WPH can be a bitter taste due to the smaller protein fragments.

* Caseinate (as either calcium caseinate, sodium caseinate or potassium caseinate) Caseinate contains greater than 90% protein and is the most soluble form of casein--allowing it to mix easily in fluid, making it a top choice by manufacturers of protein powders. It is formed by the reaction of casein with an alkaline substance such as calcium, sodium or potassium. This raises the mineral content of the product. If you're trying to avoid sodium (such as during a shredding phase), read labels carefully and consider avoiding products with high amounts of sodium caseinate. Alternatively, if you want to boost your calcium intake, products that are high in calcium caseinate will give you extra.

* Micellar casein (MC) MC is made by separating the casein portion of milk from the lactose, fat and whey by microfiltration. This form of casein is not denatured (meaning the protein isn't altered), unlike the other forms, which are often treated with heat or acid. As the name implies, MC can still form micelles upon rehydration with fluid, which makes it much slower digesting than the other casein proteins. The protein drink you take before bed should contain a good deal of MC, to prevent your body from going catabolic during your nighttime fast.

* Hydrolyzed casein protein (HCP) This protein is formed by the hydrolysis of casein. Unlike the other caseins, particularly MC, HCP is rapidly digested--at a rate similar to WPH.

FLEX readers know that protein is the bedrock of bodybuilding nutrition: Without adequate intake, you won't build optimum muscle. Determining what types of protein work best for you and when you should ingest them for maximum impact are critical steps toward realizing your physique goals. Experiment based on the information provided in this article and your unique requirements to put together a program of protein intake and supplementation that meets your daily needs and immediate goals. Once you've found the right mix, you'll reap the reward of enhanced muscle growth. That's jargon for "getting big fast."

RELATED ARTICLE: CHART YOUR PROGRESS

Here's a menu for what you should take and when, based on a few specific needs and assuming you're taking two supplemental protein products per day. We've anticipated four times of day when you might choose to take these supplements. FLEX recommends taking a protein supplement as your workout meal, in preference to whole-food sources.

NEED TIMING PROTEIN SOURCE DOSE (g)

Muscle growth Upon waking Whey 40-50
 Workout Whey 40-50
 Meal replacement Casein or egg 40-50
 Before bed Casein 40-50
Diet phase Upon waking Whey 20-40
 Workout Whey 20-40
 Meal replacement Casein* 40
 Before bed Casein* 40
Milk allergy/ Upon waking Egg or soy 20-50
vegetarian ([dagger]) Workout Egg or soy 20-50
 Meal replacement Egg or soy 40-50
 Before bed Egg or soy 40-50

* Avoid sodium caseinate.
([dagger]) If you don't eat eggs, opt for soy.

RELATED ARTICLE: PROTEIN PROCESSING

Manufacturers use various processing methods to separate whey protein from the lactose, fat and other components found in milk. Some of the more common methods are listed below. These terms often show up on product labels. Here's what they mean.

* Ultrafiltration A process that uses pressure and a porous membrane to separate the fat and lactose from milk proteins.

* Microfiltration (MF) or cross-flow microfiltration (CFM) A method that further separates whey protein from fat and lactose through a low-temperature process using high-tech ceramic filters that maintain the majority of the beneficial fractions. MF- and CFM-type processing removes the large fat globules that ultrafiltration cannot separate to achieve a fat content of less than 1%.

* Ion exchange (IE) A method that uses ionically charged resins and chemicals such as hydrochloric acid and sodium hydroxide to separate protein. This process is often used to produce the purest form of whey protein isolate--meaning it has the highest protein content of all whey proteins (90% or more). The drawback is that some of the beneficial subfractions are lost, particularly hunger-suppressing glycomacropeptide.

* Hydrolysis Describes the separation of protein into peptides (multiple amino-acid fragments). Hydrolysis breaks some of the amino-acid bonds in the protein chain, allowing the protein to be digested and absorbed more rapidly.

RELATED ARTICLE: OTHER PROTEIN SOURCES

* Egg protein Egg protein is one of the highest-quality proteins available. It is virtually devoid of carbs and fat, making it a good choice for those who are dieting or allergic to whey or casein (milk proteins). Egg-white protein is high in sulfur, which is critical to the body's hormone-producing pathways--meaning it can enhance muscle growth. If you do not like to eat cooked eggs, consider using an egg-white protein powder in your diet. Some products offer avidin-neutralized egg-white powder. Avidin is a glycoprotein in egg whites that depletes the body of biotin, which is essential for optimal health. You will find egg protein labeled on the ingredient list as egg protein, egg-white protein, egg-white solids and egg-white albumin.

* Soy protein Soy protein is a complete protein, yielding all of the necessary amino acids. It is produced using defatted soy flakes followed by a water or alcohol extraction process that removes soluble carbohydrates. The flakes are then dried and ground to provide either soy concentrate or isolate. Beyond the health-promoting benefits of soy, there is no reason for most bodybuilders to choose it over milk or egg proteins. In fact, due to its amino-acid composition and high solubility, it is broken down more readily in the liver than milk proteins--meaning less growth-promoting amino acids are supplied to your muscles. However, adding soy can boost any protein shake due to its high content of glutamine and arginine. Although you likely won't get enough from soy protein products to have any negative impact, some bodybuilders fear the phytoestrogens found in soy, which mimic some of estrogen's effects in the body.

Protein supplements may include the following forms of soy protein. Soy concentrate Concentrate is usually about 70% protein, relatively low in carbohydrates and low in fat. Soy concentrate can cause gas in some people.

Soy isolate Made from soy concentrate that is further processed to remove any unwanted potential gas-producing factors, soy isolate has upward of 90% protein.

* Wheat protein Wheat is another commonly used plant-source protein due to its high glutamine content. The processing of wheat protein is similar to that of soy, in that the soluble carbs are extracted to provide wheat protein that is low in carbs and fat. The next step is hydrolysis, to break up the long protein chains and create wheat protein hydrolysate--commonly referred to on protein supplement labels as glutamine peptide (although it typically contains only about 30% L-glutamine). Many protein products are fortified with this form of glutamine because it's highly stable in the stomach and readily absorbed.

BY JIM STOPPANI, PHD

PHOTOGRAPHY BY ROBERT REIFF