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marylin monroe
Showing posts with label GIP. Show all posts
Showing posts with label GIP. Show all posts

Pre-Meal Protein Ingestion to Improve Glucose Tolerance: Insulin, GIP, GLP-1 - That's the Whey(!) it Works! Plus: Even Pure Glucose Can "Improve Your Insulin Tolerance"

Can a whey protein appetizer really undo the damage of greasy fast food? Probably not, but it's still interesting to see how it affects the postprandial glycemia.
Insulin resistance is the #1 contributing factor to the obesity epidemic and despite the fact the solution is already out there (read more about the necessary lifestyle modifications), it probably won't hurt to know if something as simple as having a high protein "appetizer" before a junky meal could improve blood glucose management even further, right? "Right, 'cause protein is always, good!" Ah, no... I guess the answer is a little more complex than that... Nevertheless, I still suspect that the results, Tina Akhavan and her colleagues from the University of Toronto present in their soon-to-be-published paper in the Journal of Nutritional Biochemistry will be of interest to you.

The study results are interesting, to say the least...

... and that's not despite but rather because the researchers did not use the usual subjects (rodents, obese individuals or elderly people), but young men (aged 18-29) with a BMI of 18.5-29.4 kg/m². In a randomized cross over design (cross over means that every subject got each treatment - obviously in seperate testing sessions), the subjects drank either...
  • 300ml of a 10g or 20g whey protein solution, 
  • 300ml of a 10g or 20g glucose solution, or
  • 300ml of flavored zero calorie water 
The test drinks were consumed four hours after a standardized (junk = Honey Nut Cheerios + Skim Milk + Orange Juice) "breakfast". 30 min later the subjects were served even more junk in form of a *yummy* frozen Pizza from McCain Foods Ltd.

"Cereals", skim milk, pizza... whey alone won't help to counter that

The Pizza had been prepared "according to manufacturer‘s directions". This means that the reduction in glycemia the scientists observed in response to the protein preload were not because the pizza was still frozen... ok, before I produce even more nonsense, let's take a look at what the whey protein and glucose pre-loads did to the subjects blood glucose responses, right?
Figure 1: Glucose and insulin levels after pre-load and after meal (mean of 30-230min); all values expressed relative to water control, i.e. +85% would mean "85% higher than during control trial" (Akhavan. 2013)
If that's not your first visit to the SuppVersity, I probably won't have to explain the mechanism by which the pre-ingestion of whey (and glucose) reduces the Pizza-induced glycemia - do I? Well, I guess I better repeat it briefly:
  1. The ingestion of the whey protein triggers a significant increase in insulin - 127% for the 10g and 191% for the 20g dosage.
  2. Contrary to the glucose infusion there is no exogenous glucose that could lead to a rapid elevation of blood glucose (cf. figure 1, left → pre-values); the minimal increase you see is produced by gluconeogenesis in the liver.
  3. With the elevated insulin levels, the mean glucose levels in the postprandial phase (30min-230min after the pizza ingestion) is lower with both the glucose and whey preload. The effect is however more pronounced with whey than with glucose. The reason should be obvious: The overall amount of glucose that's got to be stored away is lower.
I know it sounds counter-intuitive, but aside from (2) the mechanism is absolutely identical for the glucose trial - with the insulin already being around low (10g) glucose preload can actually lead to lower postprandial glucose levels than the water control (this is probably only true for healthy individuals).

Insulin? Is that all, or is there more to it?

Now that we have gotten the fundamental mechanism by the means of which "glucose-" and "whey-preloading" before eating pizza can ameliorate the blood glucose surge after the meal, let's take a look at the auxiliary data.
Figure 2: GLP, GIP, PYY, CCK and Ghrelin levels before eating the pizza; all values expressed relative to water control, i.e. +85% would mean "85% higher than during control trial" (Akhavan. 2013)
As the data in figure 2 tells you the increased insulin release was brought about and accompanied by profound increases in the production of the satiety hormones GLP-1 and CCK, as well as the "insulin trigger" GIP (all these changes occured in the pre-meal = pre-pizza phase, only). Ghrelin and PYY, which play an even more important role in the regulatory process that's supposed to control our energy intake, did not show significant treatment dependent differences, though.
What's the practical relevance of these findings? Honestly, I am not sure how relevant the findings from the study at hand actually are. I mean, from a "do this" or "don't do this" point of view - not from a "understanding how things work" perspective.

SuppVersity Suggested Read: "The Satiating Truth About Proteins and Why High Protein and Low Amounts of Low GI Carbs May Not Mix As Well As Most People Think" | read more
For those who would benefit most from reductions in postprandial glycemia, i.e. the obese type II diabetic, it is questionable whether (a) the mean 7% decrease is actually making a difference and whether it would (b) even occur in someone who is having a hard time producing enough insulin to have his / her body react to it.

For the lean individual, on the other hand, the 7% reduction in gylcemia probably doesn't matter at all and the insulin spike before the onslaught of a the "perfect storm" of carbs and fats from a greasy frozen pizza could (worst case scenario) increase the chance of fat storage - I mean the glucose can go to the muscle (learn more), the fat, on the other hand must end up in your adipose organ.

I would thus strongly advice everyone to stick to my "get 30g of quality protein with every meal" recommendation, instead of turning it into a "get 30g of protein before every meal". Aside from the questionable benefits of having the protein before your meal, having it with / as part of your mwal will also direct you away from pizza and towards healthier food choices. After all, you will be hard pressed to find a pizza with 30g+ of protein in it... and I bet the novel "pizza on a stick" I told you about on Facebook, recently, probably doesn't qualify either ;-)
References:
  • Akhavan T et al. Mechanism Of Action Of Pre-Meal Consumption Of Whey Protein On
    Glycemic Control In Young Adults. The Journal of Nutritional Biochemistry. October 2013 [accepted manuscript]

On Short Notice: Testosterone - 12% Drop /W 75g Glucose? Fat Loss - Adzuki, Leucine + B6 or HiMaize? Thyroid - T3↓ + rT3↑, Is Blood Sugar to Blame and Can TUDCA Help? +More!

Image 1: It's quite funny, I am piling up so many of these interesting mini-news that I actually had to drop a few or postpone them to next week to keep the size of this post manageable without a direct brain transmission device like the one you see in this picture ;-)
"On short notice" is the name of the new 'saturdaily' SuppVersity column and therefore I will try to make it short: After all, you've got a hell lot to learn today and unless you have just crawled out from beneath your sheets, your testestorone levels and with it your cognitive abilities will aready have declined - that's not you? Well I guess you have the hubris of a boxer, then, or you did simply sleep so little that even your increased energy consumption could not make up for the memory dysfuction that's been brought about by the sleep deficit. Let's just hope that your cell mass is at least so high that your basal energy expenditure is sufficient to burn those serotonergic carb binges off, because I am pretty sure that the leucine + B6 combo from NuSirt Science won't do that for you... what? You don't understand a word? Don't worry, you will, once you are done with today's installment of "On Short Notice"...

Adzuki bean extract - just another fat binder or more?

Image 2: Those Adzuki beans look pretty much like kidney beans, don't they? Ah, btw. you did know that kidney beans contain a "carb blocker" (a molecule that hampers carbohydrate digestion; cf. Mosa. 2008) - did you?
I am really no a fan of those "anti-fat absorption agents", as most of them will have immediate or long-term consequences on your supply of fat soluble nutrients which could in fact be worse for your overall health than the few additional lbs of body fat you may be carrying around. That being said, you may still be interested in the latest results from Tomoko Kitano-Okada and his colleagues from the Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine in Inadacho, Obihiro, Hokkaido, Japan. In a combined in-vivo (rodent) and in-vitro study, the researchers found that control and high fat diets with 1% adzuki bean extract, despite having only non-significant effects on the high fat diet (HFF) induced weight gain, did not just ameliorate the HFD induced deteriorations in serum low-density lipoprotein (LDL) and triglyceride (TRIG) levels, but lead to marked improvements in LDL and TRIG in the rodents on the standard diet (55% cornstarch + 10% succrose, 20% casein, 5% soybean oil), as well.

Figure 1: Absolute total cholesterol and triglyceride levels, as well relative (expressed in percent of respective values for animals on control diet) liver and faecal matter weight and lipid content in male Fischer rats after 4 weeks on control (high carb) or high fat diets (data based on Kitano-Okada. 2012)
This is interesting as it appears to confirm the hypothesis that the Adzuki beans do not work their anti-hyperlipidemic (=cholesterol and triglyceride lowering) effects solely via their ability to increase the fat content of the excrements, but also via other mechanisms of which Kitano-Okada et al. identified the reduction of inflammatory cytokines (e.g. 24–51% IL-6 reduction following treatment with Adzuki bean extract containing polymerised polyphenols) and the likewise dose-dependent profound reduction in glycerol-3-phosphate dehydrogenase, an enzyme that is necessary to generate glycerol (fatty acids) from carbohydrates, in in-vitro cell studies with human adipocytes by up to -50%!
Implications: Just in case you are now interested in popping some of those beans you should be aware that the product that was used in the study contained 16% polyphenols (including 470 mg anthocyanidins, 20.7 mg catechins, 2.33 mg caffeic acid, 2.62 mg ferulic acid, 44.5 mg quercetin, and 102 mg protocatechuic acid), that the human dose equivalent would ~5-6g /day and that you should try to get an extract with polymerized (=interconnected) phenols, as those were roughly 2x more active in the in-vitro essays (although it is questionably if this translates into better real world results).

Marathon running is for the metabolically efficient!

Image 3: Marathoners have nothing to lose!
Just in case you have ever wondered what makes a good marathon runner a very good marathon runner, the results of a study that was published in the latest issue of Sport Sciences for Health could hold the answer: Marathon champions have a surprisingly high metabolic efficiency (Andreoli. 2012), or put more simply, they are carrying little to no (for their goals!) useless ballast like profane fast-twitch muscle fibers and only so much fat as it takes to optimally protect their organs (in percentages this is yet still way more than the guys with the "profane" fast-twitch fibers are carrying around)

As the data in figure 2 goes to show, their body cell mass (BCM), a more accurate measure of the amount of metabolically active tissue in their body than "lean mass" (Moore. 1963), is about equal to the one of division 1 football players (data compiled from Andreoli. 2003 and Andreoli. 2012), but their lean mass is much lower (as mentioned before they have no use for heavy type I and type IIX muscle fibers).
Figure 2: Body composition data (fat free  mass, body cell mass, body fat percentage) in different athletes and control (left), as well as correlation between BCMI (BCM / height) with marathon running time (right; data compiled from Andreoli. 2003 and Andreoli. 2012)
In conjunction with higher metabolic rates, of which Andreoli et al. found that they are the 2nd best predictor of marathon times (correlation r = -0.69 vs. BCMI = BCM / height with r = -0.73), a high amount of "oxygen-exchanging, potassium-rich, glucose-oxidizing, work-performing cells" (=what the BCM measures ;-) and correspondingly high resting energy expenditures (r = 0.77) do thus make the difference between victory and defeat.

Sounds strange, when you come to think about it - right? "People with higher energy expenditures make good marathon runners?" Well, I guess you better think of it differently: Bigger engines need more fuel and as we have seen yesterday, a very welcome side effect of "mitochondrial biogenesis that's induced by Chitooligosaccharide supplementaton" was an increase in endurance - that those big engines have to be fueled adequately, by the way, does also explain why people like Michael Phelps do in fact have to eat like a horse - that he really needs 12,000-15,000 calories per day is yet probably just another of those urban legends.
Implications: Interestingly enough, the necessity of having a "big engine" (=huge metabolically active cell mass) does also implicate that the formerly obese, who appear to flock around marathon or at least endurance running, with their slabs of metabolically unactive tissue and suppressed metabolic rates due to months or years of undereating and overtraining have little to no chance of ever winning a marathon race, which  - and this may be the most surprising finding of the study - is not the prerogative of the person who "burns the less fuel"  - at least not as long as nobody takes away their 30 bananas a day and the highly concentrated energy gels marathoners use on their 42-km run, I guess ;-)

Can 75g of Glucose Reduce Testosterone by 10% Within Minutes?

In a recently conducted trial, Lisa M. Caronia and her colleagues from the Massachusetts General Hospital in Boston observed an astonishing -12% drop in total testosterone within 30 min of the ingestion of an 75g of glucose - the same amount you would ingest in every regular oral glucose tolerance test (OGTT) and even less than some hilarious "expert suggestions" will tell you would need to optimally replenishing your allegedly depleted glycogen stores after an intense workout.
Figure 3: Glucose, insulin, SHBG, lepin, LH and testosterone levels in response to the oral ingestion of 75g glucose in 74 young men; data expressed relative to baseline (data adapted from Caroni. 2012)
If you take a closer look at the exact data in figure 3 you will probably be as startled with respect to the underlying mechanism behind this reduction as the researchers were. Aside from the drop in testosterone, the only statistically significant changes (indicated by * in figure 3) the scientists observed, were a profound drop in leptin and the explosive increase in glucose and insulin - both of which, the decrease in leptin and the increase in insulin, have yet been shown to augment testosterone production in previous studies (Adashi. 1982; Giovambattista. 2003). At least with respect to the drop in leptin, Caronia et al. do yet point out, that it could be a mere conseqence of "circadian fluctuations in leptin that are unrelated to glucose administration" (Caronia. 2012; those fluctuations, by the way, have been observed by e.g. Panarotto. 1999)

Symptoms of low Testosterone
  • Lean muscle loss, agitation/motor dyskinesia, decreased appetite
  • Depression, guilt, low-self esteem, anhedonia, decreased cognitive capacity
  • Increased stress, general fatigue, sleep disturbances
  • Decreased libido, decreased spontaneous erections, decreased ejaculate, erection dysfunction, decreased sexual fantasies, anorgasmia
Furthermore, neither cortisol (not shown in figure 3), a potential suppressor of testicular testosterone production, nor luteinizing hormone (LH), which stimulates testicular testosterone production and should actually increase in response to the drop in testosterone, did budge in the course of the 120 min after the 74 men (age range: 19-74 years, mean: 51.4 ± 1.4) who reported to the lab after a 12-hour overnight fast had ingested the 75g of glucose.

As Caronia et al. point out, the non-existent response of the luteinizing hormone (LH) levels to the reduced testosterone levels, is probably the only clue we have as far as the underlying mechanism of allegedly glucose-induced reduction in testosterone levels is concerned, because "one would anticipate that the decreased negative feedback of T would lead to increased LH levels" (Caronia. 2012). And though Caronia et al. are certainly right that this and the fact that this was not the case and that the effect occured in healthy, in insulin resistant and in diabetic subjects (where it was slightly more pronounced, though; data not shown), clearly "suggests an additional central component", the latter should actually, as it was observed by  Iranmanesh et al. only recently involve a drop in luteinizing hormone (Iranmanesh. 2012).

After thinking about that for a couple of minutes I was just about to write in the implications that this would be another good reason not to go overboard on fast carbs, when I remembered my previous research on all things testosterone for the "Intermittent Thoughts on Building Muscle" Series and what the scientists themselves had said about the declining leptin levels - well, let's take a look at what the testosterone levels of both young and old men do between 8:00am and 12:00pm, i.e. during the exact time the subjects in the Caronia study ingested their allegedly anti-androgenic bolus of 75g of glucose:
Figure 4: An analysis of the natural diurnal testosterone rhythm in young men (dotted line in graph in the background; Diver. 2003) reveals that the "drop" in testosterone in response to the OGT is likely only a consequence of the pronounced diurnal rhythmicity of the total testosterone levels - in older men we see the exact same phenomenon, but the effect is about 50% less pronounced.
The data from the Diver study in figure 4 does not leave a slight doubt that the OGTT, or rather the 75g of glucose the subject had to consume probably had no independent effect on the level of testosterone and that the decline Caronia et al. observed is simple a result of the natural diurnal rhythm. This does not exclude that the latter is per se connected to food intake as the availability / influx of energy is, beside light, probably, the most important setscrew for our clock-genes.
Image 4: Conclusions are rarely 100% conclusive.
Implications: There are actually two important take home messages from this study and "carbs are so bad for you" is not one of them:
  1. draw your own conclusions, and don't trust those of others blindly regardless of their "credentials"
  2. make sure that you don't ignore the diurnal rhythmicity of testosterone, and are thus fooled to believe that short term changes in the +/- 50% range would make you build or lose muscle, let alone your virility
The second take home message is also of great importance when you test your own testosterone levels and/or read about the testosterne boosting magic of the latest supplement scam (aka "natural testosterone booster"). As you can see, you can easily achieve a  70-80% increase or decrease in testosterone by simply measuring at different points in the day.

On Very Short Notice

  • Figure 5: Changes in fatty acid metabolism (top) and inflammatory markers (bottom) in response to 4 weeks of thrice daily NuFit (250mg leucine + 30mg vitamin B6) supplementation to 20 obese men and women (based on Zemel. 2012)
    Astonishing improvements in RQ & fatty acid oxidation from 2g of leucine and 30mg vitamin B6 - Although you need to be somewhat cautious with a study that was financed by NuSirt Sciences the producer of the 750mg leucine + 10mg pyridoxin supplement under scrutiny (Zemel. 2012), the effect the ingestion of those caps had on the fatty acid metabolism and moreover the expression of inflammatory markers in 20 overweight or obese subjects was literally marvelous (I leave the interpreation of this term up to you ;-). A decrease in respiratory quotient (=greater fatty acid, lower glucose oxidation), an increase in total fatty oxidation per day and more importantly and probably causally the decreases in TNF-alpha and CRP are changes I would not have expected to see within 4 weeks on 2.25g of leucine and 30mg of vitamin B6. After all,  you should see similar effects with almost every cheap (or expensive) BCAA supplement on the market - aside from even greater amounts of leucine most of them contain at least 10mg of additional B6.
  • Fat burning machines can't have orange juice for breakfast - The additional 210kcal the subjects of a 2012 trial by scientists from the Children’s Hospital Oakland Research Institute consumed in form of "healthy" orange juice were not just more or less empty calories, they also reduced the postprandial fatty acid oxidation by whopping 25%. This lead Stookey et al. conclude that "independent of a state of energy excess, [drinking] a caloric beverage instead of drinking water with a meal [will decrease] the amount of fat consumed in the meal before their next meal." (Stookey, 2012) If you want to become / stay a fat burning machine (and in my humble opinion even if you just want to stay lean and healthy) you better eat your fruit and never drink it (let alone other caloric beverages, see "Fat content per Energy Drink 0g, Fat Gain Per Energy Drink 16g").
  • Image 5: The first hit on google says HiMaize will cost 8$/340mg; mimicking the dosage used in the study would thus be ~1$ per day; relatively cheap if you consider that it is not necessary a supplement, but can also be used for baking & co
    Resistant starch could stop and reverse developing diabetes - scientists from the University of Surrey and the venerable Imperial College in London were able to show that their 12 overweight (BMI 28.2±0.4 kg/m2) prodiabetic subjects' first-phase insulin secretion, which is the one that determines whether you do or don't go hyperglycemic right after the ingestion of a meal, by improved by ~35% after only 4 weeks of consuming a mildly resistant (60% resistant / 40% digestible) maize starch. Probably as a direct result of this early pro-insulinogenic effect, the HiMaize260 RS2 starch produced a -10% reduction in fasting blood glucose, compared to a regular tapioca starch of which the subjects in the control group consumed only 27g to assure that they would ingest equal amounts of glucose (Bodinham. 2012).
    Despite the fact that WM HDP is an artificial restistant starch, of which even less will be digested and absorbed as glucose in the small intestine, these results do confirm what we have already seen in the WM HDP studies and what some of the latest blogposts bordering on dietary fiber have hinted at, as well (e.g."Weightloss Threesome"): The effects of these not, or only partially digestible fibers and carbohydrates go way beyond simply filling you up or being non-insulinogenic (=not causing an insulin spike as even the low GI starches do). There is however, as Carolin L. Bodinham and her colleagues rightly point out, need for "further studies [...] to confirm these findings and to elucidate the mechanisms" and, as I would add, to identify whether or not this could work for people who have already developed type II diabetes, as well.
  • Counter-intuitive effects of high glucose-dependent insulinotropic polypeptide (GIP) levels in form of increased insulin and reduced obesity: While the hitherto published studies on WM HDP (see previous bullet point) clearly suggest that part of its fatburning effect is mediated by a reduced, even almost non-existant GIP (and subsequently insulin response), a recent study from Canada clearly suggest that whenever you do consume regular starch a more pronounced incretin response will not just avoid hyperglycemia (due to the more pronounced release of insulin from the pancreas), but also improve / prevent adipose tissue inflammation, hepatic steatosis (non-alcoholic fatty liver disease) and even weight gain - remember: we are talking about higher insulin responses, here (Kim. 2012)! Unfortunately, the anti-obesity effect Su-Jin Kim and his colleagues observed in their experiments with GIP-overexpressing rodents, were mostly a direct consequence of reduced energy intakes and that those hardly ever translate into the real world is something I believe I don't have to tell you, right?
  • Figure 6: If your body does not convert T4 into T3 adequately taking levothyroxin (T4) may even worsen many of the symptoms of hypothyroidism due to increased conversion to r-T3 and an even more sluggish metabolism that certainly won't help to get blood glucose back under control (see also "Natural Thyroid Treatment with food")
    Low T3 syndrome (pseudo-hypothyroidism) or diabetes? This is an "oldie, but goldie", i.e. a study I happen on while doing research on this and that... in this case I do not even really know how this study appeared on my radar, but according to Kabadi et al. high blood sugar in type II diabetes does reduce the conversion of the "inactive" form of thyroid hormone, T4, to its active cousin, T3 and increases the conversion of T4 to rT3 (reverse T3). The latter is believed to act similar to a receptor blocker, which hinders T3 do to its metabollically activating job. The statistically highly significant (p < 0.0001) correlation (r = 0.611) the scientists observed between rT3 and fasting blood glucose would suggest that improper blood glucose management could be the root course of the heavily lamented high rT3 levels of thousands of posters on various bulletin boards all across the Internet (Kabadi. 1982). Now, the good news is that the researcher found that by controlling blood glucose levels you can return your rT3 and T3 levels back into the normal zone. 
  • Tauroursodeoxycholic (TUDCA) and 4-phenylbutyric (4-PBA) increase T4 to T3 conversion - The chemical chaperones TUDCA and 4-PBA, of which the former has as of late been hailed as the new "milk thistle", i.e. the go-to-supplement for liver health among athletes who use oral anabolic steroids, could turn out to be a valuable tool not just to escape from the aforementioned vicious circle of low T3 and high rT3 levels, but also as a means to kickstart your metabolism. Although this hypothesis is based on data from a combined in-vitro + in-vivo rodent study (da-Silva. 2011), the shift away from glucose and towards fatty acid oxidation, as well as the doubled activity of the fat burning brown fat and the profound improvements in glucose tolerance, da-Silva et al. observed in their high-fat fed rodents certainly won't harm your physique.
  • Figure 7: Narcicistic personality traits of kickboxers, freestyle and  Greek Roman wrestlers, Boxers and Weightlifters (based on Tazegül . 2012)
    Weight lifters and boxer are the most narcissistic athletes - At least among the five groups the Turkish scientist Ünsal Tazegül analyzed for his recently published paper, the 17-19-year old male boxers and weight lifters had the most pronounced narcissistic character traits. While the boxers were the most exhibitionists and pretentious, the weight lifters were the most rebellious, inadaptable, spiteful, disrespecting (subsumed under exploitation) and ambitious, power-thirsty and spiteful among the subjects who participated in this study. Interestingly enough, the freestyle wrestlers appeared to be the guys with whom you would probably get along best. So what does that tell you? Nothing... and that's why this study is only on very short notice ;-)
  • If you don't sleep yourself smart, you got to binge yourself half-smart: Just in case you have already forgotten what you read a few paragraphs above, the reason could be sleep deprivation. And while cognitive deficits due to sleep deprivation is nothing essentially new, another thing, namely the effectivity of increased daytime energy intake to recover your mental capacity, is something a recent study by Nina Herzog et al. has investigated for the first time (Herzog. 2012). Unfortunately, binging rescues only the procedural part of your memory (where you store how to brush your teeth before you go to bed ;-), it will not compensate for the detrimental effects a lack of adequate sleep will have on your declarative memory. If you also  take into account that it is going to make you fat and sick, I would thus suggest you go to bed now, after all you havale already done the single most important thing of the day - you've gotten your daily dose of SuppVersity news! And let's be honest, you don't want to forget any of these valuable lessons, do you ;-)
References:
  1. Adashi EY, Fabics C, Hsueh AJ. Insulin augmentation of testosterone production in a primary culture of rat testicular cells. Biol Reprod. 1982 Mar;26(2):270-80.
  2. Andreoli A, Melchiorri G, Brozzi M, Di Marco A, Volpe SL, Garofano P, Di Daniele N, De Lorenzo A. Effect of different sports on body cell mass in highly trained athletes. Acta Diabetol. 2003 Oct;40 Suppl 1:S122-5.
  3. Andreoli A, Marfe G, Manzi V, Sinibaldi-Salimei P. Is body cell mass a predictive index of performance in male recreational long-distance runners? Sport Sci Health. 2012; 8:47–50
  4. Bodinham CL, Smith L, Wright J, Frost GS, Robertson MD (2012) Dietary Fibre Improves First-phase Insulin Secretion in Overweight Individuals. PLoS ONE 7(7): e40834.
  5. Diver MJ, Imtiaz KE, Ahmad AM, Vora JP, Fraser WD. Diurnal rhythms of serum total, free and bioavailable testosterone and of SHBG in middle-aged men compared with those in young men. Clin Endocrinol (Oxf). 2003 Jun;58(6):710-7.
  6. Giovambattista A, Suescun MO, Nessralla CC, França LR, Spinedi E, Calandra RS. Modulatory effects of leptin on leydig cell function of normal and hyperleptinemic rats. Neuroendocrinology. 2003 Nov;78(5):270-9.
  7. Herzog N, Friedrich A, Fujita N, Gais S, Jauch-Chara K, et al. (2012) Effects of Daytime Food Intake on Memory Consolidation during Sleep or Sleep Deprivation. PLoS ONE 7(6): e40298.
  8. Iranmanesh A, Lawson D, Veldhuis JD. Glucose ingestion acutely lowers pulsatile LH and basal testosterone secretion in men. Am J Physiol Endocrinol Metab. 2012 Mar;302(6):E724-30.
  9. Kabadi UM, Premachandra BN, Maayan M. Low serum 3, 5, 3'-triiodothyronine (T3) and raised 3, 3', 5'-triidothyronine (reverse T3 or RT3) in diabetes mellitus: normalization on improvement in hyperglycemia. Acta Diabetol Lat. 1982 Jul-Sep;19(3):233-42.
  10. Kim S-J, Nian C, Karunakaran S, Clee SM, Isales CM, et al. (2012) GIP-Overexpressing Mice Demonstrate Reduced Diet-Induced Obesity and Steatosis, and Improved Glucose Homeostasis. PLoS ONE 7(7): e40156.
  11. Kitano-Okada T, Ito A, Koide A, Nakamura Y, Han KH, Shimada K, Sasaki K, Ohba K, Sibayama S, Fukushima M. Anti-obesity role of adzuki bean extract containing polyphenols: in vivo and in vitro effects. J Sci Food Agric. 2012 Apr 11.
  12. Moore FD, Olesen KH, McMurray JD. The body cell mass and its supporting environment. WB Saunders, Philadelphia, 1963.
  13. Mosca M, Boniglia C, Carratù B, Giammarioli S, Nera V, Sanzini E. Determination of alpha-amylase inhibitor activity of phaseolamin from kidney bean (Phaseolus vulgaris) in dietary supplements by HPAEC-PAD. Anal Chim Acta. 2008 Jun 9;617(1-2):192-5. Epub 2008 Feb 1. 
  14. Panarotto D, Maheux P. Reduction of plasma leptin during a short-term fast, an oral glucose tolerance or a meal test can be a misleading bias in clinical studies. Diabetologia. 1999 May;42(5):634.
  15. da-Silva WS, Ribich S, Arrojo e Drigo R, Castillo M, Patti ME, Bianco AC. The chemical chaperones tauroursodeoxycholic and 4-phenylbutyric acid accelerate thyroid hormone activation and energy expenditure. FEBS Lett. 2011 Feb 4;585(3):539-44.
  16. Stookey JD, Hamer J, Espinoza G, Higa A, Ng Vivian, Tinjero-Deck L, Havel PJ, King JC. Supplement: 2nd Forum on Child Obesity Interventions: Orange Juice Limits Postprandial Fat Oxidation after Breakfast in Normal-Weight Adolescents and Adults Adv Nutr July 2012.
  17. Tazegül, Ü. Comparison of narcissims in some branches of athletes. International Journal of Sport Studies 2011, 1 (4), 168-179.
  18. Zemel, M.B.; Bruckbauer, A. Effects of a Leucine and Pyridoxine-Containing Nutraceutical on Fat Oxidation, and Oxidative and Inflammatory Stress in Overweight and Obese Subjects. Nutrients 2012, 4, 529-541.

Whey More Insulinogenic Than White Bread: Insulin Spike is Mediated by GIP Secretion in the Gut & Effect of EAAs on the Pancreas + Why Whey is Still the Better Choice

Image 1: Peter Czerwinski, aka Furious Pete, certainly did not care about the pro-insulinogenic effects of whey, when he ate 900g of it within 3:30min, click here to watch his record (Furios Pete, 2010)
Among muscle heads and physical culturists, alike, whey protein has become almost synonymous with building slabs of lean muscle.What many of the protein fans - especially the low carbers - tend to overlook or ignore, though, are the pro-insulinogenic effects of whey protein, in general, and purified whey protein isolates and hydrosolates, in particlar, which do not just augment the insulin release in response to carbohydrate ingestion (Morifuji. 2010), but exert a decent increase in pancreatic insulin release in and out of themselves (Claessens. 2009). Further evidence on the hitherto not yet fully understood mechanism behind the whey induced increase in insulin comes from a recently published paper by Albert Salehi and his colleagues from the Lund University in Sweden, the University of Copenhagen in Denmark and the Oxford Center for Diabetes, Endocrinology and Metabolism in the UK (Salehi. 2012).

Whey vs. white bread and human plasma as incubation medium

In the aforementioned paper, the scientists present the results of a combined in-vivo + in-vitro trial on the effects of glucose, amino acids and amino acids mixtures (as they are found in whey) on pancreatic insulin production and its relationship to the incretin response (release of incretin hormones from specialized cells in the small and large intenstine). To this ends, the researchers had their subjects, four men and two women (healthy non-smokers, normal-weight, age 20-30y), consume test meals containing either white bread (3.7g of protein) or whey (16.7g of protein), after an overnight fast, on two different occasions. The meals had to be consumed within 12 minutes and blood samples were taken 7.5,  15, 30 and 45 min after the start of the meal.
Figure 1: GIP and GLP-1 response to whey and white bread (left, top & bottom); insulin release (%) per islet relative to glucose after incubation with different amino acids, amino acid mixtures and mixture + GIP (Salehi. 2012)
As you can see in figure 1 (left), the ingestion of  ~20g of whey protein (containing 16.7g of protein + lacose + minimal amounts of fat) produced a significantly more pronounced in increase in glucose-dependent insolinotropic peptide (GIP, see previous post "Waxy Maize Reloaded" for more information) than the white bread meal. GIP is a hormone-like substance that is produced by the enteroendocrine cells of the gut lining, amplifies the glucose-induced production of insulin in the pancreas, slows down digestion, increases glucose absorption, ramps down fatty acid oxidation and sets you into energy "storage mode" - unfortunately in both forms, skeletal and liver glycogen and fat!
Figure 2: Simplified schematic illustration of mechanism behind the EAA induced GLUT-4 increase in skeletal muscle (click here to learn more)
GLUT-4 activation - another reason, why whey is way better than sugar: If you remember Monday's blogpost on the isolated effects of essential amino acids (EAAs) on the GLUT-4 (glucose transporter = the shuttle that carries glucose from the blood stream into the cell) expression on skeletal muscle cells, it is evident that contrary to sugar or most forms of carbohydrates, whey protein, or rather the essential amino acids in whey, cod, soy, beef, pea, egg and other high EAA protein sources exert nutrient-repartitioning effects due to selectively increasing insulin induced glucose uptake in skeletal muscle and constant glucose uptake in adipose tissue (Lavigne. 2001).
Against that background it is not surprising that the combined effects of GIP (figure 1, top-left) and the amino acid induced increase in insulin production (figure 1, right, orange) lead to a more than 7-fold increase (compared to glucose control) in pancreatic insulin production after incubation of mouse Langerhans cellls (the cells of the pnacreas that are responsible for insulin mediated glucose control) with sera containing a mixture of EAAs and GIP that was matched to the respective EAA and GIP concentrations in the preceding whey vs. white bread human experiment.

Don't worry there are also benefits that can compensate for the insulin spike

Now these results certainly seem odd, after all "the experts" say that insulin is the root cause of all evil! Now whey spikes insulin and GIP and still we see study after study popping up, reporting "beneficial effects" of whey protein on glucose metabolism and overall health - how can that be? The reasons are manifold and actually quite straight forward:
  1. Insulin is not the devil - Contrary to common believe the problem is not insulin, but insulin resistance and overspilling glucose stores. If your insulin spikes and you are not insulin resistant, the cells will suck up glucose, your blood sugar will drop and your insulin will drop as well; so, in terms of negative side effects, the most obvious one would be postprandial hypoglycemia in response to large boluses of whey protein (and even that is usually compensated for by increases in glucagon and consequently gluconeogensis)  - that the latter can have long-term detrimental effects on insulin sensitivity is a whole other issue, though...
  2. Many studies use (pre-)diabetic subjects - In a pre-diabetics an increase in insulin release due to whey will improve postprandial glycemia and must thus be considered beneficial - it's "nature's insulin supplement", if you will, and particular helpful for non-insulin-dependent type-II-diabetics.
  3. Effects on skeletal muscle are neglected - Anything that can potentially help build and maintain muscle tissue (and we all know whey can do that) will help with glycemia, obesity and lipid metabolism, because the increase or (esp. in the elderly) maintenance of skeletal muscle mass ("Metabolic Currency" - Carl Lanore) will allow for greater intra-muscular glucose stores and fatty acid oxidation (assuming you are still insulin sensitive, cf. 1)
  4. The "satiety hormones" are overlooked - Similar to the muscle building effects, the increase in GLP-1, a hormone which is by no means just responsible for inducing satiety (read all about GLP-1 in my previous post "Eat More, Burn More and Lose Fat Like on Crack With GLP-1") have been hitherto largely ignored. And that despite the fact that increases in GLP-1 could be among the main reasons that whey and other EAA-rich protein sources have repeatedly been shown to help weight- and, more importantly,  fat loss and increase metabolic health (Ranganath. 1996; Baggio. 2007; Akhavan. 2011; Gerspach . 2011). 
Image 2: Real foods are better protein choices for the last weeks of a contest prep (image directly from Adelfo Cerame's kitchen)
In other words, while some of the "beneficial effects" in obese and insulin resistant individuals could actually turn against lean, active individuals, the muscle-building and "satiety hormone" induced metabolic effects make up for the potential fat storage in scenarios of energy overconsumption (remember: there is a certain margin of carloric surplus, where the laws of thermodynamics do apply, cf. "A Tale of Macro- and Micronutrient Modifications")

Whey is probably not your best choice for the final weeks of a contest prep, though

Still, if you are in the final phase of prepping for a contest and want that "paper-thin" skin conditioning, like our common friend Adelfo Cerame does, real-food protein sources like chicken, fish, lean meat etc. should be your main sources and protein shakes, an exclusive post-workout thing (in the last days, maybe not even that).

References:
  1. Akhavan T, Luhovyy BL, Anderson GH. Effect of drinking compared with eating sugars or whey protein on short-term appetite and food intake. Int J Obes (Lond). 2011 Apr;35(4):562-9. Epub 2010 Aug 24.
  2. Baggio LL, Drucker DJ. Biology of incretins: GLP-1 and GIP. Gastroenterology. 2007 May;132(6):2131-57.
  3. Claessens M, Calame W, Siemensma AD, van Baak MA, Saris WH. The effect of different protein hydrolysate/carbohydrate mixtures on postprandial glucagon and insulin responses in healthy subjects. Eur J Clin Nutr. 2009 Jan;63(1):48-56. Epub 2007 Sep 12
  4. Gerspach AC, Steinert RE, Schönenberger L, Graber-Maier A, Beglinger C. The role of the gut sweet taste receptor in regulating GLP-1, PYY, and CCK release in humans. Am J Physiol Endocrinol Metab. 2011 Aug;301(2):E317-25. 
  5. Lavigne C, Tremblay F, Asselin G, Jacques H, Marette A. 2001. Prevention of skeletal muscle insulin resistance by dietary cod protein in high fat-fed rats. Am. J. Physiol. Endocrinol. Metab. 281:E62–71
  6. Morifuji M, Ishizaka M, Baba S, Fukuda K, Matsumoto H, Koga J, Kanegae M, Higuchi M. Comparison of different sources and degrees of hydrolysis of dietary protein: effect on plasma amino acids, dipeptides, and insulin responses in human subjects. J Agric Food Chem. 2010 Aug 11;58(15):8788-97.
  7. Ranganath LR, Beety JM, Morgan LM, Wright JW, Howland R, Marks V. Attenuated GLP-1 secretion in obesity: cause or consequence? Gut. 1996 Jun;38(6):916-9. 
  8. Salehi A, Gunnerud U, Muhammed SJ, Ostman E, Holst JJ, Björck I, Rorsman P. The insulinogenic effect of whey protein is partially mediated by a direct effect of amino acids and GIP on beta-cells. Nutr Metab (Lond). 2012 May 30;9(1):48.

Glycemic Load, the GI's Complex Brother, Turns Out to Be A Good Predictor of Postprandial GLP-1 and GIP Response

What does the glycemic load tell you about these foods? Right, an apple a day keeps the doctor away, ice-cream makes a healthy sweet treat and apple juice is one of those purportedly healthy drinks that are not on iota better than coke. It may be partly due to the correlation of low GL and high micronutrient content that going by the glycemic load is not the worst way to pick quality foods.
After taking one week off, the SuppVersity Science Round Up is back today. As usual the show will kick off at 1PM EST (update: download podcast) and I cannot complain about not having enough stuff to talk about. So here is a sneak peak on the news line-up for today:
  • insulin in the brain - how it's keeping you lean
  • breast cancer - protective & useless micronutrients
  • prenatal caffeine - negative effects on male offspring
  • mouth rinsing - caffeine & carbs, both work
  • ashwaganda - Lance's new dope?
  • betaine - the ergogenic w/ anti-NASH effect
There is more - as usual, so don't worry, there is more than enough left for the "Seconds", tomorrow ;-)

But now for the sugary news of the day...

The myth of the healthy low-GI diet is crumbling like stale white bread. Still, if you look around at diets that work (both for losing weight, as well as for weight maintenance and overall health), you will realize that they are mostly moderate in GI and, what's way more important, almost always have a low GL. It would therefore be negligent to abandon the whole notion of the importance of the glycemic response to certain foods. After all, it's practical relevance has been established in various contexts:
  • performance fuel for athletes (O'Reilly. 2010)
  • blood sugar reductions in type II diabetics (Fabricatore. 2011)
  • various types of cancer (Meyerhardt. 2012; Hu. 2013)
  • other chronic diseases (Barclay. 2008)
That said a recently published study by Shauna S. Runchey and her colleagues from Europe and the US sheds some light on one of the potential underlying mechanisms by which low glycemic load diets can promote health / ward off disease and could help you improve your exercise performance and physique.

Low GL foods are mostly healthy micronutrient-rich foods

What's the Glycemic Load (GL)? The glycemic load (GL) basically is an extension that to the GI concept that renders it practically relevant by weighing the GI with the amount of carbohydrates you ingest. Thus a high GI food with a low carbohydrate content (e.g. many fruits and certain vegetables) will have a medium, in some cases even low glycemic load. As the name already implies the GL does therefore give you an idea of the degree of blood glucose elevation a certain food will actually produce, thus making a statement about both nutrient quantity and quality.
You can find a  very comprehensive list of GLvalues for all sorts of foods and even whole meals here.
Before we do actually take a closer look at the study design and the results, the researchers present in the latest installment of the medical journal Metabolism, I just want to remind you of the fact that many of the natural low GL foods are laden with anti-oxidants, polyphenols, flavenols, fiber and all sorts of other healthy stuff so that many of the aforementioned benefits are probably a result of the perfect synergy of these (and other) micronutrients and cannot be attributed to the low glycemic load, alone.

The latter is obviously also the case in the trial at hand. And this goes despite the fact that the macronutrient composition, 15% energy from protein, 30% energy from fat and 55% energy from carbohydrate, of the high- (GL 250) and low glycemic load (GL125) diets the 89 overweight–obese (BMI 28.0–39.9kg/m²) and lean (BMI 18.5–25.0kg/m²) healthy adults had to follow for 28-days each was identical  (the study used a randomized controlled cross-over design, meaning that all subjects participated in two trials consuming both the high and low GL diet for 28 days each; the wash-out period in between was likewise 28 days long).

In that the 2x higher fiber intake in the low GL group may be only one example of potentially meaningful differences, which could partly explain the differential postprandial incretin (GIP and GLP-1) response you see in figure 1 (Weickert. 2005; Ma. 2012).
Figure 1: Glucose, Insulin, Insulin / Glucose ratio (marker of insulin sensitivity / glucose clearance), GLP-1 and GIP area under the curve after the ingestion of a standardized breakfast containing ~575kcal at a protein / carb / fat ratio of 11/32/80 (high GL) and 114/27/94 (low GL); data expressed relative to intergroup means (based on Runchey. 2013)
In that, it is interesting to remark that the fasting levels of glucose, insulin, etc. did not differ significantly between the high and low GL groups. They were however across the board more favorable in the low GL group, so that you could argue that the difference may have reached statistical significance after another months or so on the respective diets.

The fatter you are the more you benefit

Suggested read: "Burn Fat Like on Crack W/ GLP-1" (read more)
The probability that a longer study period would have yielded statistically different inter-group differences is by the way much higher in the participants with higher body fat percentage (women >30%, men >25%; measured by DEXA), where the differences in incretin (GLP-1 and GIP) baseline levels had a 2x higher p-value, i.e. were much closer to being statistically significant, than they were in the lean(er) study participants.

Against that background it is also questionable how significant the switch from a higher to a lower GL diet would be for you, who will hopefully have made it below the 30%, respectively 25% body fat mark for men and women already.

"Tell me about those glycemic loads"

If you take a peak at GL table, you will still realize that going by the glycemic load, can lead you to health-foods you may not even have considered eating or drinking before. What about the anti-catabolic tomato juice, for example? It has a GL of 4 compared to the highly juicy version of coke, called "apple juice" with a GL of 12 (even in its unsweetened, natural incarnation; cola has "only" 15, see table 1 for more).
Table 1: The glycemic loads of a couple of selected drinks and foods (picked from various websources)
As the example of the openly hailed apple juice, but also the unrighteously dreaded ice-cream goes to show you, GL based food choices can make sense... after all, you'd be way better off drinking tomato juice during a workout and having some ice-cream on your cheat day than drinking the some "healthy apple juice" and having a handful of dried fruits, like raisins as a sweet treat.

But isn't the GL just another fad? Not really. The GI is in fact mainstream and practically useless. Low glycemic load diets on the other hand have actually busted the even more mainstream-ish "just cut your fats" diets that are still hailed as the go-to standards by way too many nutritionists in various studies - e.g. 5x more weight and 2x more fat loss from a low GL vs. low fat diet in Ebbeling, 2007.
Bottom line: Just as with all those quantitative markers of "food quality", a term that has the word "quality", not quantity, in its name already, you better not base your dietary choices one concept alone. That the glycemic load of your diet probably is one of the better (mainstream) indicators of dietary quality.

That this is also due to the fact that a low GL does usually correlate with a higher micro-nutrient is yet a different story, though. Furthermore, it should be obvious, even if there may be certain timepoints, e.g. post-workout, and purposes, e.g. glycogen replenishment, when you want to prefer meals with higher glycemic loads (e.g. instant oats vs. quaker oats, bananas vs. apples and rice vs. salad).

References:
  • Barclay AW, Petocz P, McMillan-Price J, Flood VM, Prvan T, Mitchell P, Brand-Miller JC. Glycemic index, glycemic load, and chronic disease risk--a meta-analysis of observational studies. Am J Clin Nutr. 2008 Mar;87(3):627-37.
  • Fabricatore AN, Wadden TA, Ebbeling CB, Thomas JG, Stallings VA, Schwartz S, Ludwig DS. Targeting dietary fat or glycemic load in the treatment of obesity and type 2 diabetes: a randomized controlled trial. Diabetes Res Clin Pract. 2011 Apr;92(1):37-45.
  • Hu J, La Vecchia C, Augustin LS, Negri E, de Groh M, Morrison H, Mery L; the Canadian Cancer Registries Epidemiology Research Group. Glycemic index, glycemic load and cancer risk. Ann Oncol. 2013 Jan;24(1):245-251.
  • Ma J, Pilichiewicz AN, Feinle-Bisset C, et al. Effects of variations in duodenal glucose load on glycaemic, insulin, and incretin responses in type 2 diabetes. Diabet Med 2012;29(5):604–8.
  • Meyerhardt JA, Sato K, Niedzwiecki D, Ye C, Saltz LB, Mayer RJ, Mowat RB, Whittom R, Hantel A, Benson A, Wigler DS, Venook A, Fuchs CS. Dietary glycemic load and cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803. J Natl Cancer Inst. 2012 Nov 21;104(22):1702-11.
  • O'Reilly J, Wong SH, Chen Y. Glycaemic index, glycaemic load and exercise performance. Sports Med. 2010 Jan 1;40(1):27-39. 
  • Runchey SS, Valsta LM, Schwarz Y, Wang C, Song X, Lampe JW, Neuhouser ML. Effect of low- and high-glycemic load on circulating incretins in a randomized clinical trial. Metabolism. 2013 Feb;62(2):188-95.
  • Weickert MO, Mohlig M, Koebnick C, et al. Impact of cereal fibre on glucose-regulating factors. Diabetologia 2005;48(11): 2343–53.