Significant Weight Gain W/ Whey vs. Casein?! Anabolism / Muscle-Protection or Fat Gain Despite Hitting the Weights?

While being misinterpreted as an "anti-whey" study by one of you, the latest whey as your main protein source study from Brazil only adds to the evidence that there's something special about whey.

One thing I like about writing this blog is that I have a lot of contact to you, the readers. One of you recently sent me the link to a study from the University of Ouro Preto in which the authors report what he called a "disconcerting" weight gain when exercise and weight training were combined. A closer look at the study reveals, however, that this "disconcerting" weight gain (even though that is not totally obvious) is probably good news.

But before we get to the implications and interpretations, let's first take a look at what the scientists did and what they observed. You'll see that this is of paramount importance wrt to not misinterpreting the weight gain in Figure 1.

Note that the study at hand is not about High-protein diets - with 14% some may call it deficient

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Being aware that whey protein (WP) is known for its nutritional value and antioxidant properties, the authors speculated that the latter, or rather the protective effect they would have on the muscle tissue, would be another important contributor to Wheys beneficial effects on skeletal muscle development.

To test their hypothesis that a reduced muscle damage and thus reduced effort to rebuild the broken tissue before accumulating new muscle would contribute to the muscle building effects of whey protein in resistance training individuals, the authors used a model study: in thirty-two male Fischer rats who were randomly assigned to control sedentary, control exercised, whey protein sedentary, and WP exercised groups (n=8/group), half of the rodents (those in the exercise group) were subjected to an interesting resistance training regimen:

"RE consisted of inducing the animals to perform sets of jumps in a circular plastic container with a depth corresponding to 150 % of their body length. Weights were attached to the animal’s chest to promote submersion and the resistance to the exercise. When the rats touched the bottom of the container, they had to jump to emerge from the water to breathe. The RE program consisted of inducing the animals to perform four sets of 10 jumps per day, five times per week for 8 weeks. A one-minute rest interval was included between each set of jumps. Exercise intensity was increased weekly by changing the maximum weight supported by each animal to perform the set of jumps correctly (~25 % of body weight in week 1, ~30 % in week 2, ~ 35 % in week 3, ~40 % in week 4, ~45 % in week 5, ~50 % in week 6, and ~ 55 % in weeks 7 and 8); 55 % of body weight was the greatest weight supported by the rats to perform all jumping sets correctly" (Teixeira. 2016)

Now, what is particularly interesting about the study is that the researchers did not add the whey protein to the diet, but simply replaced the regular 14% protein in form of caseinate in the rats' AIN-93M chow with whey protein (still only 14% of the energy).

Why is it important that the scientists replaced the protein source? If Teixeira et al. had simply added extra-whey on top, you could always have argued that the effects they observed would have been the mere result of extra protein, not some special quality (in this case most likely the antioxidant effects) of whey.

Against that background, it is quite interesting to see how significant the effect of whey turned out to be... at least in the exercised group, where you can easily see in Figure 1 that the initially identical weights differed significantly at the end of the 8-week study. Since differences occurred only in comparison to the control + exercise group and we don't have total lean and fat mass data, it is, unfortunately, impossible to tell for sure how much if any of the gained weight was, as the previously mentioned SuppVersity reader feared body fat and how much was muscle weight.

Figure 1: Yes, for sure - at first sight, this logs bad for whey and good for the low-protein AIN-93M standard diet (Teixeira. 2016); I mean, the rats gained the least weight? Well, that's one of the common misunderstandings I had in mind when I started the SuppVersity. Science is not always as straight-forward as you think. So read the rest of the article before you freak out or argue that "this is just because it's rodents" - that's pathetic, anyway).

What we can say for sure, is that the exercise regimen triggered significant muscle-specific mass reductions (in gains), unless its negative effects on the rodents muscle was buffered by the pro-anabolic and anti-oxidant effects of whey protein (see Figure 2, where the %-ages over the bars in the "muscle weight (g)" columns indicate the difference between sedentary control and the rodents who did the jumps for 8 weeks).

Figure 2: Changes in body weight (%-ages indicate relative weight change from baseline), muscle weight and food intake (%-ages indicate difference between exercise and control group | Teixeira. 2016)

Accordingly, it would be wrong to use the study at hand to make a case against whey protein and to call it an obesogen, i.e. another of the many foods that contributing not just to weight, but also and maybe even specifically to fat gain - in spite of full commitment (the rodents obviously had no choice, which is a clear strength of the often criticized rodent studies) to a rather intense exercise regimen (see previous quote).

So, if it's not the "disconcerting news" that whey could make you fat and/or blunt weight loss what is it, then, that the study at hand tells us. Well, I guess there are two answers: Answer (a) is a confirmation of the authors' hypothesis that whey protein has significant antioxidant and anticatabolic effects. Answer (b), on the other hand, is not as favorable for whey protein is (a) as it emphasizes that, without exercise, simply adding whey protein to the diet won't build any extra muscle... speaking of muscle, I've communicated with the authors who confirmed that they "did not evaluate body composition in these rats" (so it's not that they just didn't report it, because it may not be that relevant for their specific study interest), but found "that WP exercised rats showed a better body composition and exercise performance" (private communication); and, what's more, to quantify the last-mentioned effects, will be the goal of follow-up studies.

But what about body com-position? As explained in this bottom line, an assessment of the body composition was beyond the scope of the study at hand. Luckily, you can find evidence of whey's ability to and superiority in (a) augment/ing training-induced improvements in body comp (Hayes. 2008) and (b) po-sitively alter the body comp of free-living, untrained adults (Baer. 2011). This goes for both individuals healthy, but also and especially people who have issues with inflammation, like the overweight and obese subjects in Baer et al. (2011) who consumed 2x56 g/d of soy or whey protein for 23 weeks and saw gains in lean (+0.5 kg) and reductions in fat mass (-2.3kg) only with the latter, i.e. whey protein - not with the former, i.e. soy protein. Whether that's a result of superior or different antioxidant effects of whey vs. soy protein would need further studies, but in view of the results of the Teixeira study, it is at least not unlikely that the antioxidant prowess of whey protein (at least) partly explains its unique (vs. soy) beneficial effects in the Bear study, as well.

So, what can we really learn from this study? It's not just the "mouse or man problem" that limits the significance of the study at hand. In addition, you must not forget that weight gain (including body fat) is a mere necessity in a group of healthy growing young animals; and at the age of 60 of usually ~660 days (Chesky. 1976), the Fischer rats in Teixeira's experiment were just that: still growing.

Against that background, there's no reason to start being afraid of whey protein supplementation, because it promotes weight gain (it does ;-), but that's as the study at hand shows because "WP ingestion inhibited the oxidative effects induced by RE, including the downregulation of gene expression of glutathione system enzymes and phagocyte infiltration in gastrocnemius muscle cells" (Teixeira. 2016) and increased both body and muscle weight gain compared to exercise, alone.

The reasons you may rightly be not 100% happy with the Teixeira's latest study are thus not related to its outcome. Rather than that, it's a logical result of methodological issues that originate in the specific research focus of the paper at hand. With the goal being "to evaluate whether the antioxidant properties of WP could contribute to muscle weight gain in response to resistance exercise (RE)," (Teixeira. 2016) the potential role of fat gain is not even mentioned in the thesis statement. Accordingly, the scientists harvested 'only' the slow and fast twitch muscle fibers to measure potentially different muscle weight developments exemplarily in both, primarily aerobic and anaerobic muscle fibers. And the results confirmed what we tend to forget way too often: Whey is not 'just' a muscle builder, it's also a potent anti-inflammatory agent... but wait, you know that already if you've read my you have read my 2014 article "Whey Beyond Brawn: 10+ Things You Probably Didn't Know Whey Can Do for You" | Comment on Facebook!

References:

• Baer, David J., et al. "Whey protein but not soy protein supplementation alters body weight and composition in free-living overweight and obese adults." The Journal of nutrition 141.8 (2011): 1489-1494.
• Chesky, Jeffrey A., and Morris Rockstein. "Life span characteristics in the male Fischer rat." Experimental aging research 2.5 (1976): 399-407.
• Hayes, Alan, and Paul J. Cribb. "Effect of whey protein isolate on strength, body composition and muscle hypertrophy during resistance training." Current Opinion in Clinical Nutrition & Metabolic Care 11.1 (2008): 40-44.
• Teixeira, Kely R., et al. "Whey protein increases muscle weight gain through inhibition of oxidative effects induced by resistance exercise in rats." Nutrition Research (2016).

Eating 75-100g Fat (M-/PUFA) in the AM Improves Glucose (7-8%), Insulin (40-60%), Trigs (4-16%), GSH & MDA (40-75%)

If we assume that the protein fried eggs with its comparatively low insulinogenicity is not a problem (unlike your whey, for example), avocado and eggs fried in olive oil is the perfect breakfast to replace the liquid test meal used in the study.

There's no debating that increased amounts of free fatty acids in the blood will impair your insulin sensitivity, as they should be there only, when your supply of carbohydrate is running out, AMPK and with it the expression of lypolytic enzymes increase and the triglycerides from your fat stores are broken down into free fatty acids and released into your bloodstream where they can be used by liver, muscle and other organs as an alternative energy source.

Now, the word "alternative" is of paramount importance, here, because you'll find yourself being in (diabetic) trouble if those FFAs pile up on top of high glucose levels. This is what happens with the SAD diet and its high carbohydrate and fat content (and energy!) content.

You can learn more about fat at the SuppVersity

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It's a vicious circle: When the levels FFAs are up, insulin sensitivity goes down (after all, with a normal diet you'd have to burn the fat and spare the precious glucose | Bodne. 1997; Koves. 2008). Since there's more and more glucose spilling in over the portal-vein, though, insulin will keep increasing to a point where it does no longer simply impair, but almost block the oxidation of free fatty acids. Now, without insulin working its glucose shuttling magic, however, the cells begin to starve for glucose and... right, more FFAs are being released, the insulin resistance increases, still hardly more glucose is being shuttled into the cells to restore AMP to ATP and the process continues.

What does all of that have to do with eating more MUFAs and PUFAs to control your glycemia? Well, nothing and everything. First- and most importantly, it should remind you that this is not about eating fat with your carbohydrates. That's exactly not what the latest study from the Hospital Clínico Universitario Valencia in Spain would suggest, even though I bet you will have some idiot already have misinterpret the study in this way "for your" online. Rather than that the study was, as the abstract already tells you, conducted to ...

"[...] evaluate the changes in glycemia, insulinemia, and oxidative stress markers during an oral fat load test in nondiabetic subjects with abdominal obesity and to analyze the association between postprandial oxidative stress markers and postprandial glucose and insulin responses" (Martinez-Hervaz. 2016)

This quote also contains another important information you will have people with an agenda forget to mention: the subjects in whom the fats worked their magic were abdominally obese! Later on we will see why this is relevant and why the same rules won't apply to lean individuals, but for the time being let's firstly take a look at the exact characteristics of the N = 40 (total) subjects in the study in Table 1.

Table 1. General characteristics, fasting lipids and lipoproteins, glucose, insulin and HOMA index values in the studied groups (Martinez-Hervas. 2016); ^a control vs abdominal obesity group (p<0.01).

Even though the discriminating feature, i.e. the characteristic the scientists used to find subjects for the two groups was their waist circumference (>102/88 cm for men and women, respectively vs. <102/88 in the control group), it shouldn't surprise you that the scientists have also observed sign. differences in other anthropometric and metabolic markers such as the BMI, the level of triglycerides, blood lipids and postprandial glucose levels after an oral glucose tolerance test (OGTT | see Table 1).

Is it a problem that the male / female ratio differed? That is difficult to tell. We do know that men and women handle nutrients, esp. fat and carbs slightly differently, but I doubt that the difference between an 11/9 ratio in the control group and a 7/13 ratio in the abdominal obesity group will ruin the results of the study at hand. Nevertheless, this should be addressed in future studies.

After initial testing, the subjects from both groups ingested the same commercial liquid preparation of high-fat meal of long chain triglycerides. The product is called SuperCal and must not be confused with a vitamin D + calcium product with the same name that is being sold on the US market. From a previous European study, I've got some extra-information about its composition, namely that

"[...] 125 ml contains 60 g fat, of which 12 g are saturated, 35.35 g are monounsaturated, and 12.75 g are polyunsaturated. Each 100 ml contains <1 g lauric acid, <1 g myristic acid, 4.8 g palmitic acid, 1.4 g stearic acid, 27.7 g oleic acid, 9.6 g linoleic acid, 1.4 g behenic acid, and 0.5 g lignoceric acid" (Fernández‐Real). 

The detailed fatty acid composition of the SFAs, MUFAs and PUFAs emulsion that was administered at a dosage of 50 g fat per m² of body surface (calculate your body surface if you want to know your individual equivalent dose = result of your calculation in m² x 50g g/m²; e.g. 1.78 m² x 50 g/m² = 89 g of fat) at 8:30 after an overnight fast is not mentioned in the Martinez-Hervas study. What the authors of the study at hand tell us, however is that the likewise relevant ratio ω6/ω3 is > 20/1 - similar to the average diet, by the way; a fact that excludes that this is an omega-3 effect we are seeing, here. Similarly, exercise or previous meals, shouldn't have messed with the results, either. After all, in both groups, only water was permitted during the "eating" or rather "drinking" process, and no physical exercise was undertaken before or during the "fasted" fat loading test in the AM.

Figure 1: Overview of the rel. levels of glucose, insulin, HOMA-index, trigs, the GSSG/GSH ratio and MDA, a byproducs of lipid oxidation (Martinez-Heras. 2016); levels expressed relative to control at baseline (T = 0), see explanation below

In order to make the data more accessible (compared to the tabular overview of absolute values in thee FT) for you, I've standardized each of the measurable variables to match 100%. This means that all the fasting bars at T = 0h will be at the 100% mark, because they are what the effects of fat loading are compared to. Let's take a look at two examples:

• 

  PUFA Increases Postprandial Thermo-genesis in Women & Beyond - 14% Increase Over MUFA & SFA Sounds Huge, But Does it Matter?

  Insulin: In contrast to what you will see if you co-administer fat and carbohydrates (learn more), the administration of the high MUFA + PUFA fat supplement in the absence of carbohydrates lead to a sign. reduction of the initially 3.8-fold increased insulin levels. Not to normal levels, but at least to 158% (i.e. 1.6-fold elevated) of the fasted value of the lean subjects. Ah, but remember: All that happened with the fat load, alone, and in the absence of CHOs. In the presence of carbs the results would have been much different.
• GSSG/GSH ratio: The effects on the ratio of 'used' glutathione (GSSG) to the amount of the 'fresh' master anti-oxidant (GSH) were quasi the opposite of what the scientists observed for insulin. Here, the abdominally obese group had 2.4x elevated levels to begin with. This tells you that, compared to the normal controls, their anti-oxidant status was a mess. After only 8h, however, their GSSG/GSH ratio had not just declined, it was actually lower than the fasted value of the control group.
  
  And again, likewise similar to the effects on insulin, the control group saw benefits as well, with a 64% decrease in the GSSG/GSH ratio their antioxidant defenses did also benefit from the MUFA + PUFA load in the AM.

For other parameters you will see similar, for many of you probably surprising benefits. Things to keep in mind, though, is that we are talking non diabetic subjects in both groups, even if the abdominally obese subjects had fasting HOMA index values fourth fold higher than controls, higher fasting triglyceridemia and higher fasting oxidative stress markers. If that sounds like you, then the acute ingestion of ~75-120g (depending on your body surface) of fat on empty in the AM, when hyperlipidemia is not that much of an issue, you can benefit from a high MUFA + PUFA fat load as you would find it in an avocado + egg fried in olive oil, for example... or, as the authors of the study at hand have it:

"[O]ur study has demonstrated a significant reduction of postprandial glycemia, insulinemia, c-peptide and oxidative stress markers using an acute oral overload of unsaturated fat. We have found a significant correlation between oxidative stress markers and postprandial lipemia. There is an increase of TG achieving the maximum peak four hours after the beginning of the test. However, although postprandial lipemia has been implicated in the development of insulin resistance and oxidative stress, and despite the increase of TG, there are significant reductions of the HOMA index and oxidative stress markers" (Martinez-Hervas).

Even though you may think otherwise, the authors are also right, when they point out that "[t]he influence of dietary macronutrients in insulin sensitivity is not well known" (ibid.) This is especially true, when we begin mixing proteins, carbohydrates and fats and start to take into consideration that we can have a dozen of types of the three in a single meal.

What about me? I am not abdominally obese, will I benefit, too? If we assume that you deprive yourself of any carbohydrates (and proteins?), you should see the same benefits as the subjects in the control group - those are lower than what we see in the big belly group and may simply be a result of the moderate energy intake (that's < 900kcal before an 8h fast even for many bigger guys), it would appear as if the answer to your rightly asked question would be "Yes, you can benefit, as well." Whether this will also require you to abstain from all, not just insulinogenic dairy proteins, however, will have to be tested in future studies.

It may thus depend on the food-matrix whether the results of previous studies, most of which clearly indicate that saturated fat will increase in fasting and postprandial insulin resistance would have yielded different results if the meals were administered in the absence of carbohydrates, for example - even though, additional evidence traced these effects back to increased levels of saturated fat in the cells' phospholipids that can alter their phyco-chemical properties and decrease the glucose transporters (while MUFA and PUFA have been shown to do the opposite | Borkman. 1993). Martinez et al. who have not actually tested the effect of SFAs in their studies provide additional evidence in their discussion:

Will the additional butter on top of the potatoes reduce the insulin response? You can find the answer to this and the other questions in today's episode of "True or False?" | Learn the answer

"Iggman et al demonstrated in elderly men that palmitic acid, the major saturated fatty acid found in adipose tissue, inversely correlates to insulin sensitivity measured by euglucemic-hyperinsulinemic clamp. However, they also found a positive relation of insulin sensitivity with the content of linoleic acid in adipose tissue (Iggman. 2010). It is in accordance with our results because our commercial liquid preparation of high-fat meal of long chain triglycerides is composed in the majority by linoleic acid (59%). Furthermore, in line with our findings, the replacements of dietary saturated fat by unsaturated fat also improved fasting insulin sensitivity (Vessby. 2001).

Several other studies have demonstrated that unsaturated fat improves fasting and postprandial IR, although the mechanism is largely unknown (Wang. 2015). Moreover the PREDIMED study has recently demonstrated that unsaturated fat can improve fasting insulin sensitivity and prevent the incidence of type 2 diabetes (Salas-Salvadó. 2011).

Another thing the study could not address is the chicken or egg question: After all, you can argue athat the significant reduction in oxidative stress markers the scientists throughout the fat load test could - as a result - have improved the subjects insulin sensitivity, but - at least in theory - it is imaginable that this worked the other way around... by an unknown feedback loop.

Figure 2: Relative in-group reduction in the parameters from Figure 1 from 0h to 8h (Martinez-Hervas); in contrast to the previous figure the one at hand shows the in-group difference, i.e. the change in control at 0 vs 8h, etc.

As you see, there's still lots to be learned about dietary fat out there - including the fact that a "high fat" diet that combines high energy with high fat and high carbohydrate intakes is always detrimental for your health and should no longer be used in studies, unless the goal is to mimic the Western diet (and I beg scientists to then call it what it is, and that's not a "HFD").

Beware of dairy proteins, especially whey, but also casein are highly insolinogenic and may reduce if not reverse the effects of fat loading in the AM on glucose management and inflammation | learn more.

Bottom line: Before you get addicted to the previously suggested avocado + eggs fried in olive oil breakfast, please keep in mind that this is not what the scientists tested. Especially in view of the relatively high protein level in eggs, another study would have to make sure that the latter won't interfere with the benefits... even if that's much less likely for eggs, meat or fish than for the highly insulinogenic dairy proteins.

Furthermore, the study at hand cannot tell us anything about the long-term effects, because it is an acute intervention (not even lasting for 24h, there could have been a rebound at 12h or 24h or with the ingestion of another meal at noon, etc.) that suffers from another methodological problem.

Without a control supplement containing high(er) amounts of saturated fat, the assumption that the results were MUFA + PUFA specific is simply based on the scientists' review of the existing research (see previous elaborations + quotes). And as the scientists add, last- and [f]inally, oxidative stress markers analyzed could be also altered by others players regulating the postprandial state" (Martinez-Hervas. 2016) | Leave a comment, praise or criticism on Facebook!

References:

• Boden, Guenther. "Role of fatty acids in the pathogenesis of insulin resistance and NIDDM." Diabetes 46.1 (1997): 3-10.
• Borkman, Mark, et al. "The relation between insulin sensitivity and the fatty-acid composition of skeletal-muscle phospholipids." New England Journal of Medicine 328.4 (1993): 238-244.
• Fernández‐Real, José M., et al. "Fat overload induces changes in circulating lactoferrin that are associated with postprandial lipemia and oxidative stress in severely obese subjects." Obesity 18.3 (2010): 482-488.
• Iggman, David, et al. "Adipose tissue fatty acids and insulin sensitivity in elderly men." Diabetologia 53.5 (2010): 850-857.
• Koves, Timothy R., et al. "Mitochondrial overload and incomplete fatty acid oxidation contribute to skeletal muscle insulin resistance." Cell metabolism 7.1 (2008): 45-56.
• Martinez-Hervas, Sergio, et al. "Unsaturated Oral Fat Load Test Improves Glycemia, Insulinemia and Oxidative Stress Status in Nondiabetic Subjects with Abdominal Obesity." PloS one 11.8 (2016): e0161400.
• Vessby, Bengt, et al. "Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study." Diabetologia 44.3 (2001): 312-319.

Whey Beyond Brawn: 10+ Things You Probably Didn't Know Whey & Peptides That Form During its Digestion Can Do: From A as in Vitamin A Uptake to Z as in CanZer Protection

If you've got brawn and brain you will realize that whey is much more than a potent muscle builder.

As a SuppVersity reader, you are well familiar with the pluripotent benefits whey protein has to offer to the average and extra-ordinary gymrat. You will also be aware that it can promote weight loss and help you maintain lean muscle mass when you're dieting.

If you've read almost all ~2,000 SuppVersity articles, you will even know about the GLUT4 and thus glucose uptake promoting effects isoleucine containing dipeptides in whey protein hyrolysates, but I guess that some of the other benefits whey protein owes to its complex mixture of proteins and peptides are going to be news for you.

Learn more about the effects of your diet on your body composition at the SuppVersity

Only Whey, Not Soy Works for Wheytloss

Minimal Carb Reduction, Max. Results?

Dairy Protein Satiety Shoot-Out: Casein vs. Whey

How many Carbs Before Fat is Unhealthy?

5 Tips to Improve & Maintain Insulin Sensitivity

Carbohydrate Shortage in Paleo Land

In their latest paper in the Austin Journal of Nutrition and Food Science Rie Tsutsumi and Yasuo M. Tsutsumi provide a concise overview of the biological effects of a range of peptides and proteins in whey protein. The latter include...

• 

  Amino acid composition of whey, casein and breast milk - whey excells in terms of pro-anabolic BCAAs (McDonough. 1974)

  whey is the richest natural source of BCAA -- I don't have to tell you that, but I thought maybe there is someone who has never heard of it before ;-)
• whey protein has the highest biological value (indicative of the most balanced EAA profile) of all dairy proteins (the  biological  value  is  the  ratio  of  the amount of nitrogen that is consumed to the amount of nitrogen that is absorbed, and this value is 74 for soy protein, 71 for casein, and 104 for whey protein)
• whey protein has the highest protein efficacy ratio, i.e. the body weight increase associated with an intake of 1 g protein is 3.0 (vs. 2.0 for soy protein and 2.5 for casein protein)

Whey proteins are however far more than building blocks / muscle builders, the  proteins  in  whey  have a variety of roles and immune-related functions:

• b-lactoglobulin binds retinol (vitamin A) and promotes uptake of retinol via gut; by a similar mechanism it may also facilitate the uptake of long-chain fatty acids
• a-lactoalbumin kills tumour cells (in vitro) and exerts anti-bacterial effects in the upper respiratory systems; it has also been shown to have protective effects on gastric mucosa.

• 

  Table 1: Content of minor bioactive proteins in whey concentrates (levels are probably lower in iso- and hydrolysates | values from Smithers. 2008) and the lactalbumin fractions. Since the major proteins in whey (not listed here) can form bonds with albumin (Havea. 2001), whey is another case, where an increase in processing may lead to a decrease in beneficial biological activity.

  lactoferrin regulates the absorption of iron via gut; it will inhibit the growth of various bacteria and regulates immunological response of immunocomponent cells
• serum albumin binds and carries fatty acids and bile pigment
• immuno-globulin G involves with bactericidal (anti-bacterial) effects with complements and prevents bacteria from adhering to tissues; neutralizes toxins and viruses
• immuno-globulin A inhibits growth of various bacteria by condensing them; prevents bacteria from adhering to the surface of mucosa; neutralizes toxins produced by viruses and bacteria.
• immuno-globulin M has the same effects as IgG, but its bioactivity is stronger
• lactoperoxidase catalyzes the reaction of producing cyanogen ion with strong bactericidal power from cyanic ion and hydrogen peroxide in the body
• lysozyme kills bacteria by destroying cell walls

As the Japanese researchers point out, the mechanisms relating to the whey functions are varied. The antioxidant and detoxifying activity of whey is most likely linked to its contribution to GSH synthesis.

"Cysteine, which contains an antioxidant thiol group, combines with glycine and glutamate to form GSH. GSH is the major endogenous antioxidant produced by cells, providing production for RNA, DNA, and proteins via its redox cycling from the reduced form, GSH, to the oxidized form, GSSH. Though direct conjugation, GSH detoxifies a host of endogenous and exogenous toxins including toxic metals, petroleum distillates, lipid peroxides, bilirubin, and prostaglandins." (Tsutsumi. 2014)

The antioxidant and antimicrobial effects of lactoferrin have already been mentioned above. In addition, lactoferrin demonstrates an ability to stimulate immune responses involving natural killer cells, neutrophils, and macrophage cytotoxicity. Furthermore, a mouse study concluded that lactoferrin acts as an anti-inflammatory by regulating the levels of tumor necrosis factor and interleukin-6.

"Owing to its ability to chelate iron, organisms requiring iron for replication appear to be particularly vulnerable to the effects of lactoferrin. The protein beta-lactoglobulin contains anti-hypertensive peptides, which lower blood pressure as significantly as angiotensin converting enzyme (ACE) inhibitors. Cholesterol-lowering effects have also been noted as a result of changes in micellar cholesterol solubility in the intestine." (Tsutsumi. 2014)

Moreover, the formation of peptides through the hydrolysis of whey proteins in your tummy is a rather novel, but very interesting effect that may well contribute to the beneficial health effects of whey proteins. In fact, whey peptide is one of the major peptides that inhibit ACE (FitzGerald. 2004), which induces blood-pressure regulating effects.

It is very likely that peptides are also responsible for many of the metabolic benefits

Pal et al. demonstrated a decrease in fasting plasma concentrations of triacylglycerols after long-term whey protein intake (12 weeks) in overweight and obese individuals (Pal. 2010a,b,c). And while the mechanisms behind the effects of whey protein on triacylglycerols are not understood, Mortensen et al. proposed that a meal containing whey might have resulted in reduced production of chylomicrons and accelerated chylomicron clearance resulting from the stimulation of lipoprotein lipase by whey.

Figure 2: Changes in insulin and HOMA-IR (insulin resistance) insulin response to 12 weeks on 27g of whey vs. casein (vs. control) in overweight / obese subjects (Pal. 2010b)

This would yet not explain the significant improvements in glucose management evidenced by reduced insulin and HOMA-IR values in the whey group of Pal et al.'s 12-week intervention with 27g of whey (vs. glucose vs. casein; cf. Figure 2).

Pal et al. are obviously not the only ones, who observed significant beneficial effects on glucose management in response to the ingestion of whey protein supplements. As Tsutsumi & Tsutsumi point out "[t]he majority of these studies reported that whey protein intake decreases blood glucose and insulin levels" (Tsutsumi. 2014)

Whey a source of bioactive anti-diabetic, pro-satiety peptides?

The latter is interesting, because we know that in type II diabetics, whey protein will increase not decrease the insulin response. I that, the acute effects of whey protein on postprandial blood glucose are comparable to sulfonylureas and other insulin secretagogues used for the pharmaceutical management of hyperglycemia in type 2 diabetes. A benefit that is probably related to bioactive peptides and amino acids that are generated during gastrointestinal digestion and enhance the release of several hormones (including insulin) which are able to reduce the food intake and increased satiety (e.g. cholecystokinin, peptide YY, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1)). How exactly this works is still being researched, but both, ...

• 

  Figure 3: Effects of 48 g casein (full circles) or whey (open squares) on GLP-1 (Hall. 2003)

  the production of bioactive peptides that serve as endogenous inhibitors of dipeptidyl peptidase 4 in the proximal gut, preventing the degradation of the insulinotropic incretins GLP-1 and GIP, as well as ...
• a mechanism that involves BCAAs, specifically leucine, which activates the mTOR signaling pathway and protein synthesis leading to elevated hormone expression and secretion and increased thermogenesis

...have been brought forward and supported by research. In the end, it does not really matter how whey does it. The resulting increases in satiety, thermogenesis, and reduction of blood glucose, which is comparable to pharmaceutical treatment, support the use of whey protein in the management of type 2 diabetes and obesity, anyway.

I won't bore you with the muscle building effects of whey: You just have to click here to see previous articles on whey protein, if you actually feel you need to know more about the muscle-building prowess of whey protein.

If whey protein helps prevent or even cure diabesity it will also help to prevent a hell lot of the side effects of being an overweight type II diabetic. And still, researchers believe that there may be a more direct link than diabesity prevention to the following health benefits of whey protein that are listed in Tsutsumi & Tsutsumi's latest review (the following bulletpoints are in large parts direct quotes from Tsutsumi. 2014):

• cancer  -- A number of animal studies have examined the anti-cancer potential of whey, believed to be primarily associated with the antioxidizing, detoxifying, and immune-enhancing effects of GSH and lactoferrin.
  
  A few clinical trials have been undertaken, proposing that high levels of GSH in tumor cells confer resistance to chemotherapeutic agents. One of these studies showed that 20 patients with stage IV malignancies were treated daily with 40 g whey in combination with supplements such as ascorbic acid and a multi-vitamin/mineral formulation (See. 2002). The 16 survivors demonstrated increased levels of natural killer cell function, GSH, hemoglobin, and hematocrit 6 months later. An aggressive combination of immunoactive nutraceuticals was effective in significantly increasing natural killer function, other immune parameters, and plasma hemoglobin in patients with late stage cancers.
• hepatitis B & C -- The results of trials for the hepatitis B virus have been positive,  particularly  those  from  an  open  study  that  included  8  patients administered 12 g non-heated whey/day. The patients demonstrated improved liver function markers, decreased serum lipid peroxidase levels, and increased  interleukin-2  and  natural  killer  cell  activity (Watanabe. 1999)
  
  Regarding hepatitis C, several trials have proved inconclusive, although an initial in vitro study found that bovine lactoferrin prevented the hepatitis C virus in a human hepatocyte line (Ikeda. 1998)

• 

  Figure 4: Next to reductions in blood pressure, whey induced reductions in blood lipids are a likely mechanism behind the reduced CVD risk with whey (illustration from Pal. 2013)

  cardiovascular disease -- According to the results of a number of studies, intake of milk and milk products can lower blood pressure and reduce the risk of hypertension (Marshall. 2004). Kawase et al. performed an 8-week trial in which 20 healthy men were given a combination of fermented milk and whey protein concentrate and examined the effect on serum lipids and blood pressure (Kawase. 2000). After the 8 weeks, the fermented milk group demonstrated comparatively higher high-density lipoproteins, lower triglycerides, and lower systolic blood pressure. 
• hypertension --Various investigators have hypothesized that certain bioactive peptides formed through the hydrolysis of food proteins have the ability to inhibit ACE, and this subject has been comprehensively reviewed in a number of studies. In general, it has been claimed that a diet rich in foods containing anti-hypertensive peptides is effective for the prevention and treatment of hypertension. ACE-inhibitory peptides may be obtained from precursor food proteins via enzymatic hydrolysis, the use of viable or lysed microorganisms, or specific proteases.
  
  However, studies relating to whey peptides with ACE inhibitory activities are more limited; this may be due to the rigid structure of beta-lactoglobulin, which makes it particularly resistant to digestive enzymes. 
• osteoporosis -- Milk basic protein (MBP) is a component of whey that demonstrates the ability to not only suppress bone resorption but also stimulate proliferation and differentiation of osteoblastic cells (Marshall. 2004).
  
  The role of calcium intake in determining bone mineral mass is well recognized to be the most critical nutritional factor to achieve optimal peak bone mass; milk protein is also important for preventing osteoporosis. A number of clinical trials support milk protein’s positive effects in both men and women, the latter ranging in age from young to postmenopausal. Daily doses of 40 mg MBP (equivalent to 400–800 mL milk) appear to be sufficient to significantly increase bone mineral density and reduce bone resorption.

• 

  Figure 5: Mean (±SD) reaction time in the high stress–vulnerable (▪) and low stress–vulnerable (□) groups after consumption of a diet containing protein as sodium casein (control diet) and a diet containing α-lactalbumin–enriched whey protein (α-lactalbumin diet | Markus. 2002)

  stress adaptation -- Whey enriched with the protein alpha-lactalbumin has been shown to improve cognitive performance and mood in stress vulnerable subjects (Markus. 2002). Alpha-lactalbumin is particularly high in tryptophan, and the authors proposed that this acts as a substrate to increase serotonin levels, which may be vulnerable to depletion by chronic stress. At the completion of the studies, all of the participants had higher ratios of plasma Tryp-LNAA (the ratio of plasma tryptophan to the sum of the other large neutral amino acids), believed to be an indirect indication of brain serotonin function.
  
  Recently, de Moura et al. evaluated the effects of whey protein intake on the expression of heat shock protein HSP70 (de Moura. 2013). HSP70 confers cellular tolerance against stressors, and there was a greater increase in the HSP70 expression in the soleus, gastrocnemius, and lungs of the whey protein hydrolysate-fed rats than in the casein-fed rats.

Tsutsumi & Tsutsumi also mention the battle against sarcopenia, where whey is about as useful as it is as a muscle builder in athletes and the support of the gastrointestinal integrity that is mediated by the glutamic acid content of whey which is converted to glutamine and serves as fuel for the intestinal mucosa among the proven health benefits of whey protein, before they conclude their review by stating that we still need studies investigating the mechanisms underlying the effects of whey protein.

Stop protein wheysting!

I have to admit, I am a bit ashamed of how extensively I used the excellent review by Rie and Yasuo M. Tsutsumi when I compiled today's SuppVersity Article. What came out of it, though, is an article with so many facts about the health benefits of whey that I am confident that it contains at least one surprising study result you have not heard of before for each of you... true?

In case it didn't, stay tuned for reports on the future studies investigating the mechanisms underlying the effects of whey protein, Tsutsumi & Tsutsumi demand in the conclusion of their review: I bet you won't have to wait long for the next SuppVersity Whey Protein Article | Comment on Facebook!

References:

• de Moura, Carolina Soares, et al. "Whey protein hydrolysate enhances the exercise-induced heat shock protein (HSP70) response in rats." Food chemistry 136.3 (2013): 1350-1357.
• FitzGerald, Richard J., Brian A. Murray, and Daniel J. Walsh. "Hypotensive peptides from milk proteins." The Journal of Nutrition 134.4 (2004): 980S-988S.
• Hall, W. L., et al. "Casein and whey exert different effects on plasma amino acid profiles, gastrointestinal hormone secretion, and appetite." British Journal of Nutrition 89.02 (2003): 239-248. 
• Havea, Palatasa, Harjinder Singh, and Lawrence K. Creamer. "Characterization of heat-induced aggregates of β-lactoglobulin, α-lactalbumin and bovine serum albumin in a whey protein concentrate environment." Journal of Dairy Research 68.03 (2001): 483-497.
• Ikeda, Masanori, et al. "Lactoferrin markedly inhibits hepatitis C virus infection in cultured human hepatocytes." Biochemical and biophysical research communications 245.2 (1998): 549-553. 
• Markus, C. Rob, Berend Olivier, and Edward HF de Haan. "Whey protein rich in α-lactalbumin increases the ratio of plasma tryptophan to the sum of the other large neutral amino acids and improves cognitive performance in stress-vulnerable subjects." The American journal of clinical nutrition 75.6 (2002): 1051-1056.
• Marshall, Keri N. D. "Therapeutic applications of whey protein." Alternative Medicine Review 9.2 (2004): 136-156.
• Pal, Sebely, and Vanessa Ellis. "The chronic effects of whey proteins on blood pressure, vascular function, and inflammatory markers in overweight individuals." Obesity 18.7 (2010a): 1354-1359.
• Pal, Sebely, Vanessa Ellis, and Satvinder Dhaliwal. "Effects of whey protein isolate on body composition, lipids, insulin and glucose in overweight and obese individuals." British journal of nutrition 104.05 (2010b): 716-723.
• Pal, Sebely, Vanessa Ellis, and Suleen Ho. "Acute effects of whey protein isolate on cardiovascular risk factors in overweight, post-menopausal women." Atherosclerosis 212.1 (2010c): 339-344. 
• Pal, Sebely, and Simone Radavelli‐Bagatini. "The effects of whey protein on cardiometabolic risk factors." Obesity Reviews 14.4 (2013): 324-343.
• See D, Mason S, Roshan R. "Increased tumor necrosis factor alpha (TNFalpha) and natural killer cell (NK) function using an integrative approach in late stage cancers." Immunol Invest 21 (2002):137-153.
• Smithers, Geoffrey W. "Whey and whey proteins—from ‘gutter-to-gold’." International Dairy Journal 18.7 (2008): 695-704.
• Tsutsumi, R., and Y. M. Tsutsumi. "Peptides and proteins in whey and their benefits for human health." Austin J Nutri Food Sci 1.1 (2014): 9.
• Watanabe, Akiharu, et al. "Nutritional therapy of chronic hepatitis by whey protein (non-heated)." Journal of medicine 31.5-6 (1999): 283-302.

Alanyl-Glutamine or Alanine + Glutamine? Dipeptide or Free Form Aminos? What Offers Maximal Muscle Protection?

"Wouldn't have happened if she'd used alanyl-glutamine instead of regular that cheap alanine + glutamine combo!" - True or False? Recent study says: False!

If you combine your liver's favorite gluconeogenic amino acids, i.e. alanine and glutamine, into a single peptide the result is called alanyl-glutamine and marketed as the ueber-potent alternative to regular l-glutamine supplements. It goes without saying that a comparison like this is about as stupid as comparing french fries with mayo to regular french fries and saying that the former are worse because they contain more fat, or whatever. Even if we didn't care about the physiological significance of the effects of alanyl-glutamine, we would obviously have to compare the purported cryogenic effects of this "innovative" dipeptide to those of a simple combination of free form amino acids to deserve the bragging rights for having created an advanced form of glutamine.

Alanine + glutamine vs. alanyl-glutamine - fight!

By now you are probably asking yourselves why I am bothering you with things like this. Right? Well, the reason is that Éder Ricardo Petry and his colleagues from the University of Sao Paulo must recently have been pondering the same question. To answer it, they conducted an experiment that would allow them to verify if the oral supplementation with l-glutamine and l-alanine as dipeptide has more pronounced muscle protective effects than a simple mixture of l-glutamine and l-alanine (GLN+ALA, both in their free forms) in a group of Wistar rats that are subjected to intense aerobic training (treadmill).

I know what you are thinking now: "Not another rodent study...", but think about it: How many people are willing to pay $50 and more on supplements without any in vivo evidence of their efficacy let alone long-term safety? Against that background Petry's rodent is a major advancement - isn't it?

True or False: You can (ab-)use glutamine to replenish your glycogen stores!? True! It sounds strange, but according to a study from the late 20th century glutamine is a pretty effective glycogen replenisher, even in the absence of your bodies favorite nitrous glucose precursor alanine | learn more

Don't get me wrong, there are a few alanyl-glutamine studies in humans, but there is not a single one that would compare the dipeptide to a reasonable placebo in an exercise scenario. I mean, who tells me that the basketball players in the 2012 study by Hoffman et al. wouldn't have experience the same beneficial effects on basketball skill performance and visual reaction time if their rehydration solution had contained alanine and glutamine or even glutamine alone? Yes, I know... the increased absorption: Well, let's just look at a fair comparison, i.e. the study at hand, and see what happens when the dreams of supplement formulators and reality meet ;-)

Ok, back to the facts - the exercise & supplementation protocol

The male Wistar rats, the researchers used in their experiment were exercised 5x per week - at increasing intensities: Starting with 30 and 45 min of treadmill running (incline 3°) at 20 and 22.5 m/min in the first three weeks, the speed and duration of their treadmill runs increased to 60 min at a speed of 25 m/min in week four and remained like that for the rest of the 8-week study period.

The supplements were administered via oral gavage in the course of the last 3 weeks, only. The daily doses for the animals in the dipeptide (DIP) and free form amino acid groups (GLN+ALA) were...

• 1.5g/kg alanyl-glutamine in the DIP group,
• 0.67g/kg l-alanine + 1.0g/kg l-glutamine in the GLN+ALA group, and
• plain water in the control group

The amount of of alanyl-glutamine the scientists used was calculated in such a way that the total amount of l-glutamine was the same as that of l-glutamine administered in its free form.

Changes? YES! Dipeptide benefits? Not really...

The gavage was provided 1 h after the end of each session of exercise, after which the animals had with free access to water and chow. To make sure that the results of the examinations on the last day of exercise would not reflect the acute effects of a single dose of the supplements, the animals were killed 10 h after the last exercise session.

Figure 1: Plasma glutamine, glutamate, ammonium, malondialdehyde, myoglobin, and creatine kinase activity in Wistar rats supplemented with alanyl-glutamine (DIP) or regular glutamine + alanine; data expressed rel. to control (Petry. 2013)

The virtually identical increases in l-glutamine and l-glutamate, you see in Figure 1 should thus represent the baseline and not the 'immediately post supplementation level' of these amino acids. For the exercise-induced accumulation of ammonium, malondialdehyde (MDA; indicates lower lipid oxidation), myoglobin and creatine kinase (both indicate lower muscle damage) the timing is not that important, anyway. What is important, however, is the fact that there were no physiologically relevant advantages for the "super glutamine".

DHEA & estrogen are alternative muscle protectors. Despite the fact that estrogen has repeatedly been shown to have muscle protective-effects, I would not suggest you steel your granny's HRT medication. DHEA on the other hand, may be something to consider - specifically if you are about to overreach, like the male subjects in a 2012 study by Liao et al. (learn more)

If we take a closer look at the p-values and the statistical significance of these changes, it turns out that, the minor increase in glutamate aside, all of the difference to the placebo group were statistically significant. The DIP vs. GLN+ALA differences, on the other hand, were marginal and reached statistical significance only in the case of the marker of myoglobin. Where the dipeptide has a physiologically probably irrelevant edge of 9% over the GLN + ALA combination.

Figure 2: Glutathione (GSH) and glutathione disulfide (GSSG = used glutathione) levels in soleus and gastrocnemius skeletal muscles of the rodents; data expressed relaitve to control (Petry. 2013)

For the muscular GSH levels, it does not look much different. In this case, there is however not even a statistical difference between alanyl-glutamine and the simple l-alanine + l-glutamine mix - neither for the universal anti-oxidant glutathione (GSH), nor for its "used form" glutathione disulfide (GSSG).

Does that mean that alanyl-glutamine is another supplemental rip-off? I would say that it's too early to use such harsh words. There was after all one statistically, and maybe even physiologically relevant difference between the two groups I didn't mention, yet: The dipeptide group presented with a different heat-shock protein response: They had higher HSP-70 and lower HSF-1 levels in the soleus and lower HSP-70 and lower HSF-1 levels in the gastrocnemius.

"Will training your biceps, heal your heart & protect your brain!?" - a study on the effects of exercise induced HSP increases suggests so | more

In view of the fact that the subsequent "deficit in HSP70 expression" is supposed to "impair recovery from these injuries" Petry et al. are probably right to point out that

"one cannot discard the possibility that part of the beneficial effects of high-intensity exercise training may be due to the enhancement of HSP70 expression which is exacerbated by glutamine supplementation."

In view of the fact that the total amount of proteins from the HSP70 and HSF1 family was increased in both groups, and the differences appear random, it is impossible to tell, whether the slight differences in HSP expression actually matter and whether this is an advantage for alanyl-glutamine or rather for the cheap free form amino acids.

Before future studies provide additional data based on which we can decide whether these differences are relevant and why they differ between slow- (soleus) and fast-twitch (gastrocnemius) skeletal muscle fibers, I'd say that the study at hand would suggest that alanine and glutamine have muscle protective effects irrespective of whether they are bound or not, when you ingest them.

References:

• Cruzat VF, Rogero MM, Tirapegui J. Effects of supplementation with free glutamine and the dipeptide alanyl-glutamine on parameters of muscle damage and inflammation in rats submitted to prolonged exercise. Cell Biochem Funct. 2010 Jan;28(1):24-30. 
• Cruzat VF, Tirapegui J. Effects of oral supplementation with glutamine and alanyl-glutamine on glutamine, glutamate, and glutathione status in trained rats and subjected to long-duration exercise. Nutrition. 2009 Apr;25(4):428-35.
• Hoffman JR, Williams DR, Emerson NS, Hoffman MW, Wells AJ, McVeigh DM, McCormack WP, Mangine GT, Gonzalez AM, Fragala MS. L-alanyl-L-glutamine ingestion maintains performance during a competitive basketball game. J Int Soc Sports Nutr. 2012 Mar 7;9(1):4.
• Petry ER, Cruzat VF, Heck TG, et al. Alanyl-glutamine and glutamine plus alanine supplements improve skeletal redox status in trained rats: Involvement of heat shock protein pathways. Life Sciences. 20 November 2013 [ahead of print]
• Rogero MM, Tirapegui J, Pedrosa RG, Castro IA, Pires IS. Effect of alanyl-glutamine supplementation on plasma and tissue glutamine concentrations in rats submitted to exhaustive exercise. Nutrition. 2006 May;22(5):564-71.

Science Round-Up Seconds: NAC Reduces Inflammation, Muscle Injury & Cytokine Expression, but Impairs Anabolic Signaling, Satellite Cell Activity and Recovery

Inflammatory cytokines won't build muscle, but without them your body won't notice that it's time to adapt.

As a SuppVersity student and listener of the SuppVersity Science Round-Up on Super Human Radio, you will be well aware of the fact that "inflammation" is a pretty loosely - or, I should say, lousily - defined and largely misunderstood term. What most people think of, when they hear the word has little to do with our bodies cytokine reponse (which is "inflammation") and is all about oxidative stress, which is one of the triggers of the release of cytokine. This is a process of which you've already learned that it plays a vitally important role in our bodies' ability to appropriately react to the wear and tear each and every of our cells is exposed to day by day, month by month and year by year. In fact, the misunderstood "inflammation" is a vital necessity to avoid the development of cancer. After all, it is the inflammatory response to the presence of degenerate cells that is what kills them before they can start to proliferate an turn into a systemic problem.

In this context, the feared "inflammatory" markers, IL-6 (interleukin 6) and TNF-alpha (tumor necrosis factor alpha) are of paramount importance as they are part of the singaling cascade that will have our bodies' own defenses target and cull the said degenerate cells before they become "immortal" cancer cells.

Inflammation and the adaptive response to exercise - the hormesis hypothesis

Figure 1: Health and longevity as a function of mitochondrial reactive oxygen species (ROS) formation (learn more)

That being said, previous studies in healthy human beings have yielded conflicting results as far as the effect of normal-to-large doses of exogenous anti-oxidants are concerned. According to scientists like Ristow and Schmeisser from the Department of Clinical Nutrition at the German Institute of Human Nutrition in Nuthetal, Germany, the suppression of the natural / normal cytokine response to the wear and tear of exercise will blunt the hormetic (=everything that does not kill you makes you stronger) response of which they believe that it drives the beneficial effects of working out.

Yet, while there are studies that would confirm this notion, the available data is by no means conclusive and a recent close review of the literature reveals that the consumption of "passive" anti-oxidants (e.g. vitamin C, vitamin E & co, i.e. molecules that simply eradicate reactive oxygen species and will thus blunt not regulate the cytokine response) appears to have either no, or detrimental effects in younger, relatively healthy individuals, the majority of the currently available data in older and sick individuals points to benefits of modest anti-oxidant supplementation.

We know that we know too little...

In short, we are still in the limbo as far as the "to use or not to use antioxidant supplements" question is concerned. Against that background I am grateful for every study that may help us solve this "mystery" and further our understanding of when a perfectly healthy and normal physiological response becomes pathologic and whether, when and for whom the use of specific anti-oxidants may be beneficial.

If you want to hear and learn more about the study at hand, the effects of other anti-oxidants and NSAIDs, and have not had the chance to listen live to yesterday's installment of the Science Round-Up on the Super Human Radio Network I suggest you download the show before you go on reading (click here to download).

Now without taking away too much in advance the latest of theses studies, I can already tell you that the actual outcomes of the latest study from the Democritus University of Thrace in Komotini and a couple of other European institutes, could confirm the scientists' hypotheses that the use of NAC [N-acetyl-cysteine; one of the most potent anti-oxidant supplements] during an 8-day eccentric and thus particularly "muscle damaging" exercise intervention would lead to an increase in GSH availability that would [...]

• ameliorate skeletal muscle performance by reducing inflammatory processes and exercise-induced muscle injury 
• attenuate intracellular redox dependent signaling pathways

and does nevertheless raise the question whether this really is something the average, healthy athlete should be looking for.

Figure 2: Allegedly beneficial effects on the irrelevant markers of inflammation, negative effects on what you are training for - the exercise induced increase in muscle protein synthesis (as evidenced by AKT, mTOR) and satellite cell incorporation (as evidenced by MyoD; adapted from Michailidis. 2013)

If you take look at the data I plotted in figure 2 it is quite obvious that the beneficial effects the participants, 10 healthy male volunteers with at least one month of thrice weekly strength training experience who consumed 20 mg NAC/kg per day (spread in three equal doses) dissolved in a 500-mL drink that contained water (375 mL), a sugar-free cordial (125 mL), and a 2-g low-calorie glucose/dextrose powder to improve palatability, experienced, namely ...

• an attenuation of the exercise induced elevation of inflammatory markers of muscle damage (creatine kinase activity, C-reactive protein, proinflammatory cytokines), nuclear factorkB phosphorylation, and 
• an amelioration of the damage-induced strength decrease during the first 2 d of recovery,

were  accompanied by a blunted increase in phosphorylation of protein kinase B, mammalian target of rapamycin (mTOR), p70 ribosomal S6 kinase, ribosomal protein S6, and mitogenactivated protein kinase p38 (MAPK) 2d and 8days after the workout.

Now, you could well argue that this is simply a result of less damage, right?

Was it mitohormesis that helped Walter Breuning live to the biblical age of 114 (learn more)?

It would at least seem logical that reductions in structural damage and (potentially - this was not accessed) loss of muscle protein in response to the 300 eccentric unilateral repetitions (20 sets, 15 repetitions/set, 30-s rest between sets) of leg extensions at a speed of 30°/s, the participants performed on an Isoforce (TUR Gmbh) isokinetic dynamometer, would entail a recuduction in compensatory protein synthetic response. In other words, with less damage the same amount of protein (re)synthesis that's insufficient to produce gains or at least restore the baseline protein content in the non-supplemented group could  well suffice to do just that in the NAC group.

(Unfortunately?) this is nothing but a neat hypothesis - one that is not supported by the results of the study at hand, in which the scientists also observed

• a blunted increase in myogenic (=satellite cell replenishing / recruiting and muscle repairing and building) factors and
• the failure to fully recover from eccentric exercise

in the supplement group. It goes without saying that the opposite should have been the case, if our neat hypothesis in defense of NAC supplementation as a means to increase athletic performance and muscle gains by buffering the exercise induced muscle damage, were true.

It's only logical that you wouldn't want to suppress the reactive oxygen species (green-yellow) too much, as their presence in the vicinity of muscle cells (blue) is not just a "stressor", but also important signal that will trigger and regulate the adaptive response to exercise (learn more)

Bottom line: NAC turns out to be an excellent example that well-meant interventions with outcomes that have classically been associated with positive health / performance effects (reduced CK, increased GSH, etc.) do not necessarily translate into beneficial real-world effects. In fact, the long(er)-term consequences of the attenuated cytokine (I am deliberately not using the term "inflammatory", here) response to exercise will probably be rather detrimental than beneficial for the more experienced healthy (young) physical culturist.

For other individuals which have to re-establish a healthy baseline level of glutathione and cut back on non-exercise induced oxidative damage (elderly, obese, diabetics, etc.), it may yet well be the other way around. These people may only be able to benefit from the exercise-induced cytokine response, if it is not drowned by an over-abundant amount of "pro-inflammatory" cytokines from other stressors.

References:

• Michailidis Y, Karagounis LG, Terzis G, Jamurtas AZ, Spengos K, Tsoukas D, Chatzinikolaou A, Mandalidis D, Stefanetti RJ, Papassotiriou I, Athanasopoulos S, Hawley JA, Russell AP, Fatouros IG. Thiol-based antioxidant supplementation alters human skeletal muscle signaling and attenuates its inflammatory response and recovery after intense eccentric exercise. Am J Clin Nutr. 2013 May 29.

DHEA Revives Liver of Aged Rats and Improves Antioxidant Reserves and Akt Signaling in Young and Old Rats.

Image 1:  I don't think celebrities realize it, but there is more to anti-aging than an unlined face. New studies show that DHEA could after all help with all sorts of age related diseases (img. antiagingpossible.com)

It's been a while since DHEA was in the news. While I have posted a handfull of mostly beneficial findings related to dehydroepitestosterone (DHEA), the hype that sourrounded its purported anti-aging effect in the late 1990s has completely abated. In view of DHEA's implication  (or rather the lack of the latter) in age-related autoimmune disease, sexual disfunction, osteoporisis, deteroiations of lipid metabolism, type 2 diabetes and cardiovascular and liver disease (Basci. 2007- ignificance of  dehydroepiandrosterone  and  dehydroepiandrosterone  sulfate  in  different  diseases), it is questionable how people beyond the age of 40, when DHEA production declines by 2% per year(!) could not benefit from a carefully planned and monitored DHEA treatment. A group of scientists from Brazil obviously thought the same and decided to take a fresh look at what happens on a molecular level, when 3 (young rats) and 24 months (old rats) old male Wistar-rats are given 10mg/kg deyhdroepitestosterone [human equivalent: 1.62mg/kg; 80kg human: 130mg/day] subcutaneously per day for 5 weeks (Jacob 2011).

Figure 1: Relative changes in total, reduced and oxidized glutathione in young and old rats after 5 weeks on 10mg/kg DHEA (data adapted from Jacob 2011)

As you can see in figure 1, the treatment induced profound increases in total and reduced glutathione and age-dependendly increased (young) or decreased the absolute level of oxidized glutathione (GSSG). Despite the absolute increase in GSSG, usually a marker of oxidative stress, the more important GSH / GSSG ratio, i.e. the ratio of reduced to oxidized glutathion, a more comprehensive marker of the balance of pro- vs. anti-oxidant metabolic processes, improved even more in the twelve young rats, (+6% GSH/GSSG) than in their older companions (+1% GSH/GSSG).

Figure 2: p-Akt levels in young and old rats with and without DHEA supplementation (data adapted from Jacob 2011)

As a faithful student of the SuppVersity, the serine/threonine kinase Akt should not be a stranger to you, after all, mTOR and p706SK (the "muscle builders", you've read about in the context of BCAAs, leucine and exercise-induced protein synthesis), are among its intracellular substrates. In agreement with previous studies, chronic administration of DHEA increased p-Akt-expression in the study at hand (cf. figure 2). The scientists speculate "that the Akt activation in this organ [the liver] is a protective answer" and could, after all, be the underlying reason for the preservation / restauration of hepatic function in the old rats.

Image 2: Oral DHEA supplements are sold for a few bucks over-the-counter (at least in the USA). Yet,
esp. for people under the age of 35, it probably does not make sense to buy and use those. At least, for
as long as it takes for the results of the study at hand to be confirmed in humans. And the allegedly benign 7-Keto DHEA could wreak havoc on your natural corticosteroid metabolism.

So how much DHEA should I take? Given the fact that the name of this blog is SuppVersity, I should have apprehended DeDeRa's question on which form and how much DHEA I would suggest you take. My answer is quite simple: NONE! Why? Well, this is a rodent study done with injectable DHEA. Not only would it be imprudent to extrapolate any dosing suggestions for oral DHEA supplements in humans, without clinical tests, we cannot even be sure that the effects would be identical, even if we hit the right dosage. Thus, while I am convinced that DHEA is probably more benign than many other OTC "supplements", especially people under the age of 30-35 should think twice or better thrice before popping any DHEA supplement - this includes 7-keto, the cortisol-suppressant effects of which can wreak havoc on your natural corticosteroid balance, make you feel tired and sluggish and deprive your body of an important anti-inflammatory pathway.

Most importantly, however, the study does away with the longstanding prejudice that DHEA (at the given dosage) "represent[s] a toxic potential to [the] liver". The isolated finding that endogenous DHEA lead to increased oxidation in the liver (it still does, but the overall pro- vs. anti-oxidant balance still improves!), as well as insufficient funding by the pharmaceutical industry, who obviously is not interested in naturally occuring and thus non-patentable treatment methods, had been one of the primary reasons many scientists decided not to dig deeper into the ameliorative, preventive and restaurative effects of DHEA in the context of age-related diseases. Personally, I hope that the few new studies that have been published, lately, will encourage other researchers to have another look at a hormone with profound yet complex and complicated effects on numerable aspects of the mammalian metabolism.