Compared to other proteins, the most notable difference of whey is its higher percentage of essential amino acids (the ones your body does not make). Specifically, whey is the richest source of the amino acid leucine that sparks muscle protein synthesis. Researchers have discovered that when leucine levels in the blood are increased, this is a strong signal to increase the synthesis of muscle proteins. Studies have shown that whey protein consumed before or after exercise rapidly increases the rate of muscle protein synthesis.
Whey is absorbed quickly, and gram for gram contains more leucine than other protein sources. Regular consumption of whey is ideal for maintaining muscle during weight loss and muscle building when paired with exercise.
Whey reduces body fat
For example, researchers at the University of Illinois reported that women who followed diets consisting of 1,400 kcal per day and consumed 25 grams of whey protein twice daily for 6 months lost almost twice as much body weight (-8% versus -4.1%) as a group who consumed 25 grams of carbs (maltodextrin) twice daily.
In order to examine changes in the composition of the thigh area of their legs in greater detail, magnetic resonance imaging showed a greater amount of muscle tissue present and less fat in the whey group.
Should you add simple carbs to whey?
Unless you specifically want to gain weight, the answer is most likely no. The problem with consuming simple carbs with protein is that insulin levels will spike in your blood. Overstimulation of insulin by fast-acting carbs can have a more insidious effect of diverting carbs into fat storage, which is obviously not helpful with promoting favorable changes in body composition. Studies have also shown that spiking insulin levels with fast acting carbs during recovery may diminish the beneficial effects of exercise on insulin sensitivity and other health markers. There is also no good reason to spike insulin for purposes of stimulating muscle protein synthesis.
For example, two recent studies both reported that when adequate protein is provided after exercise, adding insulin-stimulating carbohydrates does not augment the response further. Thus, if you want to preserve or build muscle and gain the most benefit for fat loss and metabolic health, avoid adding simple carbs to whey protein. However, adding simple or complex carbs would be fine if you’re trying to gain weight or replenish glycogen stores after endurance-type activities.
Whey has antioxidant effects
Exercise causes an increase in the generation of reactive oxygen species, also known as free radicals, which can damage cells and even our DNA. But our body has defense systems in place to minimize free radical damage. Whey protein helps build up our natural defense systems.
For example, whey is a rich source of the amino acid cysteine (3-4 times higher than soy). Cysteine is needed to make glutathione (GSH), one of the most important antioxidant defense systems in cells. Low levels of GSH contribute to excessive oxidative stress, which can impair recovery. Supplementation with whey protein is an effective cysteine delivery vehicle. Increased GSH translates into better antioxidant capacity, reduced oxidative stress and increased exercise performance.
Whey supports immune health
Study reviews addressing the immunoregulatory activities of whey in animals and humans have revealed widespread immunotropic functions that could be attributed to a variety of naturally occurring whey fractions such as lactoferrin, glutamine, immunoglobulins, and other peptides (e.g., lysozome, beta-lactoglobulin and alpha-lactalbumin). Lactoferrin is an iron-binding glycoprotein with known immunological functions that has been shown to be absorbed intact in adult humans. Its anti-microbial activity is due to its ability to chelate iron, an essential element for many microorganisms. This same property may contribute to its ability to reduce oxidative stress. In addition, lactoferrin is known to activate natural killer cells and neutrophils.
Futher, whey contains immunoglobulins andis rich in the amino acid glutamine. During intense exercise, immunoglobulin and glutamine stores can be depleted. Therefore, resupplying your body with both using whey protein helps keep your immune system strong.
Blood pressure benefits
Several peptides from whey protein have been shown to possess hypotensive properties. The most likely mechanism for this blood pressure-lowering effect is inhibition of angiotensin-converting enzyme (ACE) activity because milk has been shown to be a rich source of ACE inhibitory peptides. Inhibition of ACE prevents the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. Whey derived peptides showing ACE inhibitory effects are released during normal digestion in the gastrointestinal tract by proteases. In one study, supplementation with a hydrolyzed whey (20 grams per day) reduced systolic and diastolic blood pressure in subjects with mild hypertension. In addition, whey reduced LDL cholesterol and C-reactive protein.
Whey concentrate vs. isolate?
The extensive research on whey suggests that its benefits extend beyond its role in building muscle anabolism to other aspects of exercise recovery, performance and health. There are many whey products available. You may see products labeled as whey isolate or whey concentrate. Isolates are more pure than concentrates, meaning the small amounts of other non-protein components (lipids, lactose, etc.) have been removed. For example, whey isolate is about 90% protein and contains virtually no lactose or fat compared to whey concentrate which is 80% protein. This is a really small difference, and it’s important to point out that the high quality proteins and peptides present in whey are similar in both isolates and concentrates.
How much and when to take?
Studies have examined a wide range of doses. More is not necessarily better. It appears about 20-25 grams of protein maximizes the increase in protein synthesis in young healthy people, and older individuals may benefit from up to 40 grams at a time since their response to protein is blunted compared to younger people. Excessive intakes higher than these amounts results in most of the protein being used as fuel. As far as timing, if muscle building is a goal, consume 20-25 grams immediately after exercise. You may also consider consuming a smaller dose before exercise to take advantage of greater blood flow to active muscles, and thus delivery of amino acids to muscle. For weight loss, whey protein can serve as a good base for a meal replacement or a snack between meals.