Once a discarded by-product, whey protein is a bodybuilding necessity.
Here are 13 reasons why.
Previously regarded as a waste product of cheese making, whey protein is now highly valued and backed with a solid foundation of good science. We are wrapping up a remarkable decade of research from around the world showing positive effects of whey on health and performance, including recent research from my lab group on the largest study to date examining the muscle-building effects of whey protein. Here are 13 reasons whey could help you.
1 Whey has more anabolic amino acids.
When whey is isolated from milk and studied separately from casein, it is clear these two high-quality proteins have very different amino-acid compositions and actions. A distinguishing feature of whey is that it has a high prevalence of essential amino acids, especially leucine, isoleucine and valine (i.e., the branched-chain amino acids). For example, whey has 50% more BCAAs than soy. Whey is the richest source of leucine, where it accounts for about 10% of all amino acids.
Leucine is well documented to have a role beyond simply providing a building block in proteins. Leucine actually signals the muscle to start making protein and build muscles.
2 Whey is digested quickly.
Another unique feature of whey is its rapid digestion and absorption. This may not seem like a big deal, but the availability of essential amino acids in the blood, especially leucine, is the principle driver of muscle protein synthesis.
Casein, on the other hand, is a slow protein, whereas most other proteins (e.g., egg and soy) have a moderate rate of passage through the gut. Blood levels of amino acid start to increase as quickly as 10–15 minutes after ingestion of whey. Independent of its amino-acid composition, the fast digestion and absorption rate has been shown to be a critical feature of whey’s ability to promote anabolism.
3 Whey rapidly stimulates muscle protein synthesis.
In head-to-head comparisons with other proteins, whey delivers a greater stimulus for inducing protein synthesis both at rest and after exercise. In a recent study, male participants consumed 22 g of whey, casein or soy isolate following a bout of resistance exercise. Rates of muscle protein synthesis over the three-hour postexercise period were about twofold higher after whey than casein, whereas soy was in between. Muscle protein synthesis was also nearly twofold more after older men consumed 20 g of whey than the casein proteins.
In a third study, researchers compared the effects of 20 g of whey versus casein after a single bout of resistance exercise. During the first three hours of recovery, whey-induced increases in protein synthesis was 25% higher than casein, but during the second half, casein was 32% higher than whey. This is consistent with the fast-acting effects of whey and the slower but longer-lasting effects of casein.
4 Whey has antioxidant effects.
Excessive generation of reactive oxygen species (ROS) can impair recovery and health if not balanced by antioxidant defense systems. Whey is a rich source of cysteine and thiol groups that are rate-limiting for synthesis of glutathione (GSH), one of the most important antioxidant defense systems inside cells. Supplementation with whey protein is an effective cysteine delivery vehicle as shown by increased GSH in immune-deficient states, such as cancer, HIV and chronic intense exercise training.
5 Whey enhances immune function.
Immune-enhancing effects of whey could be attributed to a variety of whey fractions such as lactoferrin, and other peptides such as lysozome, b-lactoglobulin and b-lactalbumin. Whey also contains immunoglobulins and is rich in the amino acid glutamine; both can decrease with intense exercise and therefore are important for a healthy immune system, which is vital for optimal health.
One recent study showed that a single serving of whey in healthy subjects resulted in a rapid increase in phagocytic activity of monocytes and mobilization of natural killer cells into the circulation, indicating quick activation of the immune system.
6 Whey decreases blood pressure and improves vascular function.
Peptides from whey have been shown to exhibit angiotensin-converting enzyme (ACE) activity. Inhibition of ACE prevents the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. Supplementation with hydrolyzed whey (20 g per day) for six weeks reduced systolic blood pressure by 8 mmHg and diastolic blood pressure by 6 mmHg compared to control.
In a more recent study, overweight subjects who supplemented with 60 g per day of whey for 12 weeks showed decreased systolic (5 mmHg) and diastolic (2 mmHg) blood pressure, as well as augmentation index, a measure of the stiffness of blood vessels.
7 Whey enhances glucose uptake.
Rapid fluctuations in blood sugar wreak havoc on your metabolism. Recent evidence indicates that whey protein improves how the body processes carbohydrates.
In one experiment, subjects ingested 50 g of sugar solution alone (control) and then added 5, 10 and 20 g of whey protein. Compared to the sugar-only drink, the 5-, 10- and 20-g whey trials reduced the blood-sugar response by 8, 13 and 38%, respectively. Thus, whey protein may be an effective method to smooth out blood-sugar responses to high-glycemic meals.
8 Whey protects against strength loss.
Whey may also attenuate muscle damage that persists for several days after unaccustomed exercise. Australian researchers had two groups of untrained men perform a bout of intense single-leg resistance exercise. Immediately after exercise and continuing for 14 days, subjects consumed a whey or carbohydrate supplement. In the carbohydrate group, isometric strength declined 21% after one day and progressively returned to preexercise levels over the next 14 days.
In contrast, the whey-protein group only showed a 12% decline in strength, and they were nearly back to pre-exercise strength levels by four days. Thus, whey protein isolate consumed repeatedly after damaging exercise results in less loss in strength and faster recovery.
9 Whey promotes greater thermogenesis.
Protein is more thermogenic than carbs and fat, but protein sources vary. In one study, whey resulted in a greater increase in thermogenesis than carbohydrate and equal amounts of both soy and casein. Compared to the carbohydrate meal, whey protein resulted in an additional 34 kcal expended over a 5.5-hr period. Fat oxidation was also higher during whey than the other meals. Whey protein consumed before resistance exercise also significantly increased resting energy expenditure up to two days after exercise.
10 Whey decreases body fat.
A recent clinical study in 90 overweight men and women tracked body weight and composition over a 23-week period during which they supplemented twice per day (56 g total) with beverages containing whey protein, soy protein or carbohydrate while following their normal diet. Compared to the carbohydrate group, the whey group lost four more pounds of body weight and five more pounds of fat mass.
11 Whey decreases appetite.
A recent series of studies has discovered that whey protein given before a meal decreases food intake. In one experiment, subjects consumed a standardized breakfast, and then they received a “preload” shake containing either a placebo (no calories) or one with 400 kcal consisting of varying levels of whey protein (0, 13, 25 and 50 g of whey protein). Ninety minutes after the shake, they were provided a pasta-based lunch and asked to eat as much as they wished. There was a stepwise reduction in the number of calories consumed at lunch as the percentage of protein increased in the whey preload. Men decreased energy consumed at lunch by 450 kcal at the highest protein dose, whereas women only decreased energy by less than 200 kcal at the same protein level.
12 Whey preserves muscle during weight loss.
Supplementing with whey may be an effective intervention to preserve lean tissue during weight loss. Overweight women prescribed diets consisting of 1,400 kcal/day who were supplemented with whey protein (50 g two times per day) lost almost twice as much body weight (-8%) than a carbohydrate-supplemented group (-4.1%). Magnetic resonance imaging of the thigh revealed greater loss of adipose tissue in the whey group. As a percentage of the total muscle volume, there was an increased amount of muscle tissue present in the whey group. These results indicate that whey protein supplementation helps maintain muscle relative to changes in body weight and body fat during calorie-reduced diets.
13 Whey builds muscle during weight gain.
My laboratory group at the University of Connecticut recently presented results of a large prospective study comparing whey to other proteins at the American College of Sports Medicine Annual Meeting. This study involved a nine-month resistance-training and supplementation intervention with the main objective to examine changes in lean body mass determined by dual-energy X-ray absorptiometry (DXA). Healthy untrained men and women were randomly assigned in a double-blind manner to supplement daily with whey protein while performing supervised resistance training. A total of 147 subjects were enrolled and completed baseline testing.
Over nine months, the subjects were prescribed a specific diet including a constant protein intake of 1.0 g/kg (2.2 lb) body weight (not including supplementation). For the protein groups, the addition of the daily protein supplement (22 g/day) increased protein intake to 1.4 g protein per kilogram of body weight.
Subjects consumed the supplement in the morning with breakfast on nontraining days and immediately after exercise on training days. The resistance-training program consisted of supervised workouts two or three times per week.
We are currently analyzing a large number of variables, but preliminary results indicate that regular consumption of whey protein significantly increased plasma levels of leucine and BCAAs. Gains in lean body mass were significant in the whey-protein group (7.3 lb). This is the largest and longest resistance-training study comparing the effects of protein sources on gains in lean body mass.
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