According to an old nursery rhyme, “Little Miss Muffet sat on a tuffet eating her curds and whey.” The petite Ms. Muffet may not have known it at the time, but she was in the vanguard of performance nutrition. The curds in the old rhyme are the protein casein, which comprises 80 percent of the total protein content of milk; whey makes up the other 20 percent.
Whether she was an athlete or not, Muffet was eating the best combination of proteins for building muscle and strength. Anyone who’s read up on nutrition realizes that the proteins in milk have absorption properties that favor an overall anabolic effect.
Whey is considered a fast-acting protein, rapidly absorbed and peaking in the blood after 90 minutes. That favors muscle protein synthesis and rapid availability of essential amino acids. The casein portion is slowly absorbed over an extended time—up to seven hours. While that doesn’t do much for muscle protein synthesis, its slow trickle of amino acids into the blood has an anticatabolic effect. In other words, not breaking down muscle encourages muscle building.
When you view the plethora of commercially available whey supplements, it’s hard to imagine that whey was once considered a cheese-manufacturing waste product. Well, some scientist took a closer look at the actual nutritional content of whey and came away impressed: Whey is one of the richest natural sources of essential amino acids. Its essential amino content includes 26 percent branched-chain amino acids, which are also known as “muscle aminos.” Not only are they metabolized much more in muscle than in the liver like other aminos, but they also play a pivotal role in muscle-protein-synthesis reactions. They act as a metabolic stand-in during times of low-energy availability in muscle.
Many nutritionists decry the use of commercial protein supplements, noting that getting protein from normal food sources isn’t that difficult. True, except that they’re overlooking such aspects of protein as whey. While whey is milk-based, it contains a host of other small proteins, called bioactive peptides, that offer impressive health benefits. Many of them help build muscle, stave off illness and aid muscle recovery after intense training. In fact, the most recent research relating to whey and health has looked at the effects of whey peptides.
A Box Within a Box
1) Beta-lactoglobulin. BLG is the most abundant protein in milk. Perhaps strangely, it’s not found in human, rat, mouse or guinea pig milk but represents 50 percent of the total whey content of cow’s milk and 12 percent of its total protein. The ratio of whey to casein in cow’s milk is 20-to-80 and in human milk 60-to-40. Think about that the next time you read that a protein supplement is based on “mother’s milk.” Most supplements are not and instead duplicate the formula in cow’s milk.
BLG is likely the major milk allergen, and because it doesn’t exist in human milk, many human bodies aren’t prepared to deal with it, so it produces allergic effects. While it sounds bad, the problem is easily handled by probiotics that blunt the allergenic effect.
BLG provides peptides, which are small chains of amino acids that engage in biological activity in the body. One, called lactokinin, inhibits angiotensin-converting enzyme, which has the effect of lowering elevated blood pressure. Another peptide, beta-lactotensin, works in an opposite manner, increasing blood pressure, but it also has an antistress effect and reduces sensitivity to painful stimuli. Other studies say that it improves memory and may reduce cholesterol when given as an injection.
2) Alpha-lactalbumin. ALB is the reverse of BLG in one respect: Human milk contains 25 percent ALB; cow’s milk, 5 percent. ALB is a potent immune stimulator and appears to help protect against several types of cancer, including breast and colon cancers. Another notable feature of ALB is its rich content of the essential amino acid L-tryptophan. Studies show that humans who take in whey rich in ALB fall asleep faster and wake up more refreshed in the morning. The increased tryptophan availability from ALB also leads to more of the brain neurotransmitter serotonin, which helps to prevent depression and the desire to eat sweets.
3) Glycomacropeptide. GMP is rich in branched-chain amino acids but lacks the aminos phenylalanine, tryptophan and tyrosine. One major commercial purveyor of whey supplements formerly claimed in ads that GMP was a potent appetite suppressant. That was based on findings that it aided the release of a gut peptide called cholecystokinin, which is known to turn off the appetite. When humans were given purified GMP, however, the CCK effect didn’t occur. Even so, GMP does offer potent immune-boosting effects. It also increases the absorption of zinc, which is required for the function of several anabolic hormones, such as testosterone, IGF-1 and insulin.
4) Proteose peptone-3. PP3 is present in cow’s milk whey but not human milk whey. It’s produced through the fermentation of fat-free cow’s milk. Similarly to other whey peptides, PP3 is a potent immune enhancer. A synthetic fragment of PP3 called lactophoricin is a potent bacterial inhibitor.
5) Lactoferrin. LF may be the most valuable protein found in whey. It destroys bacteria by blocking the bacteria’s use of iron, which the bugs need for survival. LF has the ability to enhance immunity to prevent cancer as well as suppress inflammatory disease. It increases bone formation and can even inhibit the viruses that cause hepatitis.
Whey is also rich in the sulfur-containing amino acid cysteine, the direct metabolic precursor of a major antioxidant of the body, glutathione. Studies show that athletes given whey supplements have increased muscle endurance, less fatigue and increased recovery, which is attributed to glutathione, especially its antioxidant properties.
Does Whey Help You Lose Bodyfat?
Recent research points to another effect of whey that goes beyond its established anabolic effects in muscle: improved body composition. One of the primary ways that whey operates is by modulating your appetite. Its amino acids work with various gut hormones to tell the brain that you feel full. Whey is better at suppressing appetite than a placebo, carbohydrates and even other proteins. That’s significant because protein itself has effects in terms of making you feel full. It also explains why most studies prove that higher-protein diets are superior to lower-protein diets in aiding bodyfat loss.
Whey fractions like GMP and other peptides help bring on the release of gut hormones that turn off the appetite. Whey also helps bring on insulin release, which not only helps transport amino acids into muscle but also turns off the appetite after meals. It makes for higher insulin release than casein does. When added to a meal containing rapidly digested carbs, whey boosted insulin concentrations 57 percent greater than the carbs alone. The key aminos in whey thought to be responsible for the insulin effect are the branched-chain amino acids.
Upgraded insulin release also explains why whey is the protein of choice as a postworkout recovery supplement. When used in conjunction with high-glycemic—that is, rapidly absorbed—carbs, whey boosts insulin release more than carbs alone. The greater insulin spike also fosters more rapid muscle glycogen replenishment, as well as more muscle protein synthesis, mainly because of whey’s high natural essential amino acid content.
Another study, one involving young men, showed that 45 grams of whey protein containing 15 percent GMP suppressed food intake more than egg whites and soy protein at a pizza meal within 60 minutes. Whey reduces food intake more at 90 minutes after intake than casein does, but casein is going stronger than that at the 150-minute mark. Leucine, one of the branched-chain amino acids, can enter the brain, where it markedly reduces appetite. Whey is rich in leucine, which is a key regulator of muscle protein synthesis; that partly explains why it’s so effective at boosting muscle protein.
A recent study showed that when a special peptide from whey is added to a drink containing 50 grams of glucose—the most basic sugar—it slows the entry of glucose into the blood.1 The effect was thought to be due to enhanced insulin secretion from eating the whey peptide. Another study consisted of two groups put on diets reduced by 500 calories a day. Some of the subjects also got a whey supplement. Those whose diet included whey lost significantly more bodyfat than those on the diet without whey. In addition, those on the whey supplement experienced a greater retention of lean mass.2
In relation to insulin response, a type of predigested whey supplement called whey hydrolysates appears to be superior to normal whey.3 That makes sense, since whey hydrolysates have the most rapidly released amino acid content of any whey supplement.4 A greater insulin release is particularly important to older people, since only higher-than-normal blood insulin exerts anabolic effects in older people. Some studies suggest that whey hydrolysates may also enhance recovery from intense exercise. One found complete recovery after intense eccentric exercise in only six hours when subjects took a whey hydrolysate supplement.5 While that is likely the result of more rapid amino acid uptake with whey hydrolysates, other studies show more rapid absorption of leucine and the other branched-chain amino acids with whole-whey-protein supplements rather than whey hydrolysates.6
One reason that weight training boosts muscle protein synthesis is that it activates a system that controls the use of amino acids for that purpose. A key element there is known as mTOR. Once activated, mTOR induces a host of downstream metabolic proteins known as “translational factors” that trigger muscle protein synthesis. A key facilitator of mTOR activity in addition to resistance exercise is leucine. Since whey is particularly rich in leucine and the other BCAAs, as well as essential amino acids, it makes sense that adding whey to a weight-training program would extend the muscle-protein-synthesis process, and that’s precisely what recent studies have shown.7
One study showed that supplementing with whey in conjunction with a weight-training program lowered myostatin—a protein that blocks muscle growth—above and beyond what occurred with training alone. Some of the same authors published a later study that confirmed the mTOR-extending ability of whey when used with a weight program, but they conversely found that taking in whey after the workout blocked the lowering of myostatin that would otherwise have occurred then. The whey also slightly depressed testosterone; however, the authors note that neither effect is significant enough to blunt muscle gains.
Another frequent issue with whey involves the milk sugar lactose. Many people are intolerant of lactose, and when they take in a certain threshold of milk products, they suffer such gastrointestinal problems as excessive gas and bloating. One solution to that is to use only whey supplements that have a higher protein content. For example, ion-exchanged whey contains 90 to 95 percent protein and only 2 percent lactose. If you don’t want any lactose, choose a whey that’s processed to be all or mostly lactose-free. Hydrolyzed whey contains an average of 5 percent lactose, which usually doesn’t cause problems.
So, as you can see, whey is far more than just a protein supplement. It gives you essential amino acids for muscle protein synthesis and also provides “hidden” active factors not immediately apparent, such as the many bioactive peptides that support health and prevent disease, as well as help lower bodyfat while maintaining muscle. What more could any bodybuilder ask for?
source:ironmanmagazine.com
