Friday, September 14, 2012

Aspartame's Anti-Insulinogenic Effects During a Workout; Optimal Protein Intake on a Diet is Relative. Plus: Folate Fortification, Spirulia, Succinate, Sucrose, Pork Brain & the Low Cholesterol-Suicide Connection Reviewed!

Unbelievable: The results of the latest study from the University of Western Sidney appear to suggest that you could keep your insulin levels at bay, if you mixed your sugary intra-workout supplement with aspartame-laden diet coke instead of water! The mechanism that's behind this phenomenon does yet still have to be elucidated.
You may be surprised to see a long headline, a long post and a couple of bullet points: "Looks like On Short Notice, reads like On Short Notice, but is not published on Saturday? What's that?" The answer to this question is easy. Lot's of interesting stuff I have come across as of late! And while some of them, like the study on the marginal utility of higher protein intakes on a diet would actually deserve their own post, I decided to give you the "long(er) version of a short notice" in order not to miss any of them... and yes, this means there is going to be more than today's news on the unexpected anti-insulinogenic effects of aspartame, the only partly expected outcomes of the US folic acid fortification program, the aforementioned protein study, the usefulness of spirulina, succinate and sucrose supplements for athletes and physical culturists and some brainy insights into a possible connection between low cholesterol, depression and suicide risk in men and women... ah, ok I see, you are already reading the aspartame item - well, go for it!
  • The astonishing anti-insulin effects of intra-workout aspartame consumption Meanwhile even bodybuilders who are injecting and "supplementing" with all sorts of unquestionably unhealthy stuff are so afraid of the hitherto still rather vaguely established pro-carcinogenic effects of aspartame that supplement companies place huge stickers on the boxes of their products saying "ASPARTAME FREE!" Now, I am pretty sure that a recently published study that was conducted by scientists from the School of Science and Health at the University of Western Sydney in Campbelltown, Australia (Siegler. 2012), won't do much about that, but you will probably have to agree that it is still remarkable, to say the least, that the co-administration of an artificial sweetener which has not produced any glucose, insulin or whatever response in previous trials (cf. "Sweeter than your tongue allows") would do that!?
    Figure 1: While the mechanism is still unknown and the results need to be repeated in a second experiment, there is no question that the drop in insulin during the workout (see arrow(s)) which occurred during the carbohydrate + aspartame trial in the presence of identical glucose ingestion and blood glucose levels warrants further investigations (based on Siegler. 2012)
    During the four trials, which were separated by 7-10 days of rest, the 9 healthy, recreationally active males (age: 22±2 years; height: 180±9 cm; weight: 78.6±8.5 kg; participating in regular physical exercise at least twice per week) who had volunteered for this (in the eyes of some aspartame extremists, probably unethical undertaking ;-) cycled fasted for 60 minutes in a climate controlled laboratory. The only difference between the four sessions was the "intra-workout nutrition" the participants were fed, with...
    1. carbohydrate - 2% maltodextrin and 5% sucrose (figure 1, C),
    2. carbs + aspartame - 0.04% aspartame with 2% maltodextrin and 5% sucrose (figure 1, CA),
    3. water - plain water, only (figure 1, W), and
    4. aspartame + malto - 0.04% aspartame with 2% maltodextrin (figure 1, A)
    As it is common practice in studies like this, "all participants were instructed to follow the same diet and training schedule for the three days prior to each experimental trial." (Siegler. 2012, my emphasis)
    The respective intra-workout beverages were to be consumed in boluses of 4ml/kg body weight before and at 15-minute intervals throughout the trial. For the CHO groups this summed up to a total carbohydrate intake of 104.4±11.3g per participant and did - probably not to your surprise - cause a corresponding increase in insulin levels... with one exception, however: the intraworkout period in the CHO + Aspartame group (figure 1, red), when the insulin level dropped, during the exercise sessions and bumped back up to the same level as in the carbs only control afterwards (see figure 1).
    As the researchers point out, we do not yet have a mechanistic explanation for this phenomenon... nor can we even be sure that this was not some sort of strange artifact, so that
    "the disparity between insulin levels [does not only] warrant further investigation with a larger cohort of clinically relevant subject populations (e.g. metabolic syndrome, diabetes, etc.) [, but must also] be considered when designing nutrition-based, exercise intervention studies [in the future]" (Siegler. 2012
    That this observation could actually have very practical implications, both, in view of its potentially compromising effects on blood glucose levels in diabetics, where any insulin blocking effect of aspartame would probably reduce the already compromised glucose uptake even more, as well as in view of the anti-lipolytic (=blocks the release of fat from the cells) of insulin during a workout, which could actually be blocked with a minuscule amount of aspartame ... but alas, until the results have been confirmed and the mechanism behind this effect has been elucidated, what we are doing here is more or less intellectual masturbation - nothing to feel bad about, but still not the real deal ;-)
  • Figure 2: This is what the USDA expected to happen - more folic acid in food = higher intake (here in the elderly) = lower homocysteine levels; the reality looked pretty different, though, at least in adolescents the folic acid intake went up, but the homocysteine levels did not go down; moreover the B12 levels have declined as well... how much of this is related to confounding factors still has to be elucidated, but as of now it does not seem as if the fortification program was the success the USDA wanted it to be (Mc Bride. 2007).
    US adolescents and their "healthy grains" are now folic acid fortified, but are they also healthier? According to a study that has just been published in the Journal of Public Health, the great idea to put another artificial vitamin into our the food chain and fortify "healthy" cereal-grain products with folic acid, was so "successful" that the average US teen (14y at the time the fortification program began, 18y now) does now have 16% higher folate and 14% higher B6 concentrations.
    Instead of the expected decrease in homocysteine levels, of which scientists still believe that it plays in imminently important role in the development of heart disease, its serum levels did likewise increase by 17%, while the serum concentrations of vitamin B12 decreased by 11 % post-fortification. The additional ~118 μg folate/d the subjects ingested from the fortified food products, appeared to be particularly useless (or even detrimental?) for boys / young men whose total homocysteine (tHcy) levels increased by 24%  to a much greater extent than in the girls / young women.
    Honestly, I don't really know what to make of these results at the moment, ... at least nothing better than to shake my head over the hilariousness of trying to turn junk(-food) into (good) food by simply enriching it with artificial vitamins. On the other hand, I am happy that even Daniel A. Enquobahrie and his colleagues feel that it is "warranted to investigate the significance of these improvements in folate status on clinical outcomes, in the post-fortification era." (Enquobahrie. 2012) - and that not just because the fortification program did not produce the desired results, but also because the folic acid intake already started to exceed the RDA in many of the subjects. This, and the alarming decrease in B12 levels of which Katherine L. Tucker had cautioned in the 2007 interview with Judy Mc Bride, already, that "better diagnosis for B12 deficiency should be given high priority"(Mc Bride. 2007) do not "warrant", imho, they rather make it imperative to follow the effect of this "nationwide health program" very closely.
  • Figure 3: The principle of relativity for protein based body recompositioning diets - When it comes to weight los, the word "high" in high protein diets must always be seen in the context of habitual protein intake and to whom we are comparing our dieters; or put simply: The average SAD dieter benefits from every gram, the average bodybuilder will hardly benefit from the 7th whey shake.
    Effectiveness of high(er) protein diets for weight loss depends on spread / change vs. baseline not on total protein intake That's basically how you could summarize the conclusion of the latest review of the existing data on the influnece of (high) protein intakes on changes in body composition by John D. Bosse and his colleagues from the University of Utah. To find out whether either the protein change (=high protein diets are only effective when the change in protein intake from baseline to intervention is large enough) or the protein spread theory (=those dieters within a cohort with the highest protein intake will see the most beneficial changes in body comosition) could explain the different outcomes of previous studies best, the researches collected an impressive dataset comprising 51 peer-review studies the analysis of which yielded the following two main results (Bosse. 2012):
    1. The 35 successful dietary interventions had on average 58.4% higher average protein intakes than those trials in which the authors had not been able to observe an additional beneficial of going high protein over the standard calorical restriction approach
    2. The 17 successful (=greater anthropomorphic changes than with calorie restriction alone) of the 25 studies, where the baseline protein intake of the subjects was available, the increase in protein intake was 28.6% (if you ate 100g protein per day before, that would mean you would eat 128.6g while you are dieting), minimal increases in 4.7% range, on the other hand, did not provide any additional benefit over energy reduction, alone.
    Overall, the review does therefore support the original hypothesis of the researchers that there are certain thresholds which have to be surpassed before dieters will see any benefits from an increase in protein intake. This does yet also mean, that for someone who is already eating 200g of protein on a daily basis, the addition of a protein shake with 20g of protein is probably not going to make so much of a difference as it would be way below the 28.6% change in protein intake, the protein change theory would prescribe (see [2] in the list above). As a matter of fact going higher and higher (e.g. like eating 300g of protein per day), will, if anything stall, not propel your progress, after all, there will be too little room for other nutrients, when you are already getting the lions share of your daily energy intake from protein... and NO you cannot lose weight without being in a caloric deficit, even if that is not readily calculable by the idiotic "calories-in-vs-calories-out" equation.
  • The BMJ Supplement Review says: Thumbs up for sucrose, thumbs down for succinate and undecided  for spirulina In installment #36 of the A-Z of Nutritional Supplement Supplements, a series dedicated to review the pros and cons of purported ergogenic aids, the authors conclude that ...
    Figure 4: In view of the fact that the TCA or citric acid cycle is one of the #1 aerobic source of cellular energy (APT) and succinate is one of its intermediates it makes sense that supplementation could improve exercise performance, but hitherto this has not been confirmed.
    • ...the studies on spirulina fail to "study well-trained individuals", to use appropriate standardization regimen with relevance for physical culturists and athletes, identify the active ingredients and their effect on the antioxidant status, of which the respective scientists speculate that it would be the underlying mechanism of the observed ergogenic effects on chronic low-intensity exercise regimen
    • ...the research on succinate (only) supplementation is basically non-existent and claims with respect to its permanence enhancing effects is mostly based on theoretical considerations about its role in the TCA cycle 
    • ...despite the general trend within our society, where the overconsumption of sucrose (table sugar) is one of the major offenders to public health, "there may be value in, or at least room for, its inclusion in sports products targeting the provision of carbohydrate fuel during exercise"
    Nothing exciting, but a realistic and educative analysis, which has all the classic elements you should keep in mind, whenever you try to find out whether a product is worth its money: What research is there? What are the results? Are the positive results significant for me as a person? And... in the case of succrose: Could the use of this ergogenic aid be an obstacle for another goal of mine? I mean, you can benefit from guzzling tons of sugary drinks during your workouts, but if "looking good naked" is your primary goal and your performance only a means to an end - it is probably not wise to do so ;-)
  • Figure 5: Suicide risk in psychiatric patients /w (SA) or w/out (PS) prev. suicide attempt and surgical control (SC) in lowest, 2nd and 3rd cmp. to highest quartiles (Olié. 2011)
    Can pork brain in milk tell us something about suicide? Those of you who are on the SuppVersity Facebook news RSS channel will already know the image on the right. I only saw it today, but as Mark mentioned on my Facebook wall, he has used it (the image not the brain) in lectures before... be that as it may, that reminded me of an older study on the highly significant correlation between cholesterol levels and suicide attempts Emilie Olié and her colleagues observed in a 2010 study on the reliability of serum cholesterol levels as a predictor of the suicide risk in 3207 subjects [510 patients with a history of suicidal attempts (SA), 275 patients with no history of suicidal attempts (PC), and 2422 surgical controls (SC); Olié. 2011].
    The exact mechanism for the highly significant increase in suicide risk, esp. among women with previous suicide attempts in the lowest (1st quartile) is still not fully elucidated, Olié et al reference previous studies which suggest that low serum cholesterol levels, a "potentialmarker of central nervous systemcholesterol", impair the serotoninergic activity and" increase impulsivity" and thus precipitate to severe depression and the tendency and ability to pot a premature end to your life.
    In view of the fact that this and similar results were derived exclusively from analysis of psychiatric patients and considering that the cholesterol levels in the SA group were already significantly lower that in the PC and SC control (178±36 mg/dL vs. 217±43 mg/dL and 219±52 mg/dL, respectively) we should be very wary of transferring these results 1:1 to the "normal" people. 
I guess this is enough for today. After all, news are not so different than protein, it's the relative intake that makes all the difference - in other words: If I keep flooding you with those awesome posts, you won't appreciate each and every of them the same way you do now... and we don't want that to happen, do we? 
References:
  • Bosse JD, Dixon BM. Dietary protein in weight management: a review proposing protein spread and change theories. Nutr Metab (Lond). 2012 Sep 12;9(1):81.
  • Enquobahrie DA, Feldman HA, Hoelscher DH, Steffen LM, Webber LS, Zive MM, Rimm EB, Stampfer MJ, Osganian SK. Serum homocysteine and folate concentrations among a US cohort of adolescents before and after folic acid fortification. Public Health Nutrition. 2012; 15: 1818-1826.
  • Mc Bride. Foods To Be Fortified With Folic Acid. USDA ARS. News. February 7, 2007. < http://www.ars.usda.gov/is/ar/archive/jun97/folate0697.htm > retrieved on September 14, 2012.
  • Olié E, Picot MC, Guillaume S, Abbar M, Courtet P. Measurement of total serum cholesterol in the evaluation of suicidal risk. J Affect Disord. 2011 Sep;133(1-2):234-8.
  • Siegler J, Howell K, Vince R, Bray J, Towlson C, Peart D, Mellor D, Atkin S. Aspartame in conjunction with carbohydrate reduces insulin levels during endurance exercise. J Int Soc Sports Nutr. 2012 Aug 1;9(1):36.
  • Zemski AJ, Quinlivan RM, Gibala M, Burke LM, Stear SJ, Castell LM. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance: Part 36. Br J Sports Med. 2012 Sep;46(12):893-4.