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

Science Round-Up Seconds: Nicotine's Effect on Brain Aromatase & the Consequences, 2D:4D Digit Ratio Predicts Testosterone Response to Sprinting and All the Anti-Obesity & Pro-Brain Effects W/ Just 2 Cups of Coffee per Week?

Wallaby Lachie Turner (left), Greg Inglis (centre) & Jarryd Hayne (Stuff.co.nz) - who would have thought that the relative length of their 2nd and 4th digit could predict their testosterone response after the sprint? Not you? Well, then you got to check out the first of the short-items at the bottom.
Those of you who have listened to yesterday's installment of the SuppVersity Science Round-Up on Super Human Radio, will have realized that the show did - as usual - take a somewhat different direction than originally planned. Before I get to the actual SuppVersity Round-Up Seconds, of which there actually weren't all too many I consider absolutely newsworthy and appropriate for a written format, I thought I would briefly mention the paper on which I based the hypothesis (remember: this is nothing certain) that there may be a link between the calcium-influx into the muscle and the strength and hypertrophy effects of performance enhancing drugs (spec. those with a high anabolic : androgenic effect ratio) - for those of you who may want to follow up on this hypothesis or think Carl and I were just making things up ;-) 

The study I refer to shortly after the last break (download the podcast), was conducted by a group of researchers from the Instituto de Ciencias Biomedicas at the Universidad de Chile in Santiago de Chile, dealt with the modulatory effects of testosterone (and aldosterone) on intracellular calcium response in skeletal muscle cell cultures and not the subsequent consequences on contractile force of hypertrophy and could thus only serve as a point of departure for future investigations to either confirm or refute this idea (Estrada. 2010).

Nicotine exposure, brain aromatase and gender-specific implications

With the advent of new technologies, esp. the direct observation of aromatase activity in primate brains (Lidstrom, 1998; Kim, 2009; Biegon, 2010), our understanding of the peripheral effects of certain substances on hormone metabolism, one of the latest such insights pertains to the effects of nicotine exposure on the expression of the aromatase enzyme in the brain.
Figure 1: Effect of nicotine on brain aromatase availability in the female baboon. Representative baseline PET image coregistered with MRI at baseline and following injection of low dose (0.015 mg/kg) or high dose (0.03 mg/kg) nicotine. PET images show averaged frames acquired between 52.5 and 90 min after tracer injection, pseudocolored using the rainbow spectrum, with purple indicating the lowest density and red indicating the highest density of radioactivity (from Biegon, 2010).
In a recently published paper scientists from the Brookhaven National Laboratory Upton in New York did now connect the dots between the previously observed direct inhibitory effects on the central expression of the CYP19a mediated expression of the aromatase enzyme of nicotine and (potentially) other tobacco alkaloids. Thus, Anat Biegon, Nelly Alia-Klein and Joanna S. Fowler are not only able to explain, why women are more susceptible to the addictive effects of the nicotinic acetylcholine receptor agonist, which accumulates in the leaves of several members of the Solanaceae (nightshade) family, than men, but observations such as the early onset of menopause and lower plasma estrogen levels and correspondingly higher osteoporosis risk in female smokers compared to their non-smoking peers, as well (Daniell. 1972; MacMahon. 1982; Nusbaum. 2000; Pant. 2008; Korkor. 2009).

Table 1: Comparison of the effects of nicotine exposure and the effects of an aromatase inhibitor (at different time points in life) on sexual behavior, anxiety and depression, hot flashes, and weight gain in men and women (Biegon. 2012)
The scientists also list a couple of other ascertained side-effects pertaining which are equally important to men and women: The sexual behavior for example has been shown to drop both in response to prenatal, as well as acute nicotine exposure in male mammals - something those of you who happen to have a prescription for an aromatase inhibitor as an adjunct to their TRT regimen and did not hit the sweet spot between too much and too little estrogen, will certainly be aware of. While anecdotal evidence clearly points into that direction the scientific consensus on the negative impact of aromatase inhibitors on male libido in men (not male rodents), is however not yet clear. Personally, I believe this is partly due to the fact that pertinent studies usually deal with subjects who reduce their estrogen levels to normal, which could in fact lead to increased testosterone and DHT level in the absence of any negative side effects on the patients' libido.

If you take a look at the overview in table 1, you will however realize that other effects as the anxiolytic effects of acute nicotine exposure in adult women or the weight loss effect (which is certainly another reason women like to smoke) stand in direct opposition to the hypothesis that the majority of nicotines beneficial and negative side-effects were mediated by its effects on the aromatase enzyme. Fortunately, for most smokers, this appears to apply to the pro-Alzheimer's effects of low brain aromatase (Hiltunen. 2006), as well - at least, if we go by the conflicting results of the latest epidemiological studies, which contradict earlier findings that did even suggest that smokers would have a lower risk of Alzheimer's disease.

Alzheimer's, dementia, etc. are yet only examples of the far reaching effects brain aromatase and its regulation by nicotine and other substances such as aromatase inhibiting drugs, but also all sorts of environmental toxins with endocrine side-effects could have - so you can easily expect more interesting study results in the future.

Other news that did not make it into the show

As I have mentioned in the introduction, we did cover a hell lot of ground, so that most of the other studies are directly related to the luteinizing hormone negative feedback and thus no real "news" - I skipped discussing those, since I though that everyone listening will get the main message and did not want to bore those of you who are not interested in this topic with a show solely on the effects of nutrient deprivation and exercise on the endocrine milieu. But enough of the excuses, there is still more:
  • Right-left digit ratio (2D:4D) predicts testosterone response to exercise in 79 professional Rubgy players (Kilduff. 2012) - In the analysis, researchers from the Swansea University at the Sports Science, Talbot Building in Singleton Park,  Swansea, UK, found that despite significant differences in basal testosterone levels, the 2D:4D ratio, which is generally regarded as an indicator of in-utero androgen exposure was significantly associated with a lower testosterone response to repeated sprint-agility tests in the 25 subjects who participated in the active arm of the study.
  • Caffeine prevents weight gain and cognitive impairment by high fat diet (Moy. 2012) - This is not news? Just read on, you will soon realize that it is news! Firstly, the scientists from the University of Albany identified an ameliorative effect of caffeine on the diet-induced reduction of hippocampal expression of the brain-derived neurotrophic factor (BDNF) as the underlying mechanism behind it's neuroprotective effect (the same stuff that's also increased by exercise, by the way).

    Figure 2: Assuming this is not a mistake in the study caffeine once a week would be enough to boost the BDNF levels of junk-food and normal eaters alike (Moy. 2012)
    And secondly, the rodents received only a single, weekly intraperitoneal injection that would be equivalent to ~250mg in a human being (I double checked, the study says: "All animals received either caffeine (20 mg/kg) or saline (volume-matched), i.p., once weekly."; my emphasis in Moy. 2012). If that's not a mistake, chronic caffeine consumption may not even be necessary to see a hell-lot of the anti-diabetes and anti-neurological damage effects of coffee - just 2 cups once per week that's it!

    And if you look closely at the data in figure 2 you see that even "normal" people may benefit from this regimen.
Since tomorrow is an official installment of "On Short Notice" due, I will leave you on that flabbergast caffeine study and just remind you that there is - as everyday (guaranteed even on Christmas ;-) tons of interesting new stuff on the SuppVersity Facebook Wall, as well - let's see what we have today:
  • Insulin has anti-Alzheimer's effect - Yeah you read me right. It reduces the formation of ameliod beta plague (read more)
  • Yet more plant extracts with natural anti-cancer activity: Chamaejasmenin B and neochamaejasmin C isolated from the root of Stellera chamaejasme L known in TCM as Rui Xiang Lang D (read more)
  • Want to father a Nobel Laureate and in your early to late 30s? Than its about time you procreate! Study finds U-shaped curve for father's age and intellectual abilities of the offspring peaking at 32-37 years or so (read more
     
  • ...plus the rest I did not mention (read all)
      I guess with the podcast to listen to and some food for thought on once-weekly caffeine administration (on a side note, injecting into the intraperitoneal cavity is, for most substances, only minimally different from oral ingestion and done only to assure that the animals don't spit whatever you want them to ingest back out) you will survive the next couple of hours until the facebook news will receive another update and the next installment of "On Short Notice" is going to be published? If not, complain in the comment area ;-)
       
      References:
      • Biegon A, Kim SW, Alexoff DL, Jayne M, Carter P, Hubbard B, King P, Logan J, Muench L, Pareto D, Schlyer D, Shea C, Telang F, Wang GJ, Xu Y, Fowler JS. Unique distribution of aromatase in the human brain: in vivo studies with PET and [N-methyl-11C]vorozole. Synapse. 2010 Nov; 64(11):801-7. 
      • Biegon A, Alia-Klein N, Fowler JS. Potential contribution of aromatase inhibition to the effects of nicotine and related compounds on the brain. Front Pharmacol. 2012;3:185.
      • Daniell HW. Osteoporosis and smoking. JAMA. 1972 Jul 31;221(5):509.
      • Estrada M, Liberona JL, Miranda M, Jaimovich E. Aldosterone- and testosterone-mediated intracellular calcium response in skeletal muscle cell cultures. Am J Physiol Endocrinol Metab. 2000 Jul;279(1):E132-9.
      • Hiltunen M, Iivonen S, Soininen H. Aromatase enzyme and Alzheimer's disease. Minerva Endocrinol. 2006 Mar;31(1):61-73.
      • Korkor AB, Eastwood D, Bretzmann C. Effects of gender, alcohol, smoking, and dairy consumption on bone mass in Wisconsin adolescents. WMJ. 2009 Jul;108(4):181-8.
      • MacMahon B, Trichopoulos D, Cole P, Brown J. Cigarette smoking and urinary estrogens. N Engl J Med. 1982 Oct 21;307(17):1062-5.
      • Moy GA, McNay EC. Caffeine prevents weight gain and cognitive impairment caused by a high-fat diet while elevating hippocampal BDNF. Physiol Behav. 2012 Dec 6.
      • Nusbaum ML, Gordon M, Nusbaum D, McCarthy MA, Vasilakis D. Smoke alarm: a review of the clinical impact of smoking on women. Prim Care Update Ob Gyns. 2000 Sep 1;7(5):207-214.
      • Pant S, Shapiro CL. Aromatase inhibitor-associated bone loss: clinical considerations. Drugs. 2008;68(18):2591-600.
      • Roselli CE, Abdelgadir SE, Ronnekleiv OK, Klosterman SA. Anatomic distribution and regulation of aromatase gene expression in the rat brain. Biol. Reprod. 1998; 58, 79–87.
      • Roselli CE, Resko JA. Cytochrome P450 aromatase (CYP19) in the non-human primate brain: distribution, regulation, and functional significance. J. Steroid Biochem. Mol. Biol. 2001; 79, 247–253.
       

      Broccoli No Superfood? Female Orgasm, What's It Good For? Can Piperine Make You Lean? Skinfold Thickness, An Exact Indicator of Insulin Sensitivity? Exercise, Cortisol, BDNF, Fatigue, IGF, Pollution, NOPE, EGCG & More!

      Alberto Contador almost certainly wouldn't benefit from the use of a nitrate supplement.
      17 seconds and 5 watts! Those are the SuppVersity figures of the week and the performance "increases" which were associated with the consumption of either 0.5 L nitrate-boosting beetroot (BR) juice over a 0.5 L placebo (PLA) drink with blackcurrant juice during time trials and repeated maximal sprints, respectively, in 10 male elite cyclists who are competing at the highest domestic level in a study that was conducted by P. M. Christensen, M. Nyberg and J. Bangsbo from the University of Copenhagen in Denmark (Christensen. 2012).

      What does sound as if it could make the difference between victory and defeat, was however statistically non-significant and is further evidence of the fact that things that work in rookies are not necessarily advantageous for highly trained athletes (for nitrates benefits have been reported in untrained or recreationally active individuals by e.g. Bailey or Vanhatalo in 2010, and Lansley in 2011).

      As a SuppVersity student the specificity of the ergogenic effects of dietary supplements is yet not really news for you, but I would hope at least some of the following items of today's installment of On Short Notice are...





      Next to broccoli blueberries got an "unhonorable mention" in the Kingston University press release, as well.
      Is broccoli really no superfood? Usually this is not the place to discuss mainstream popular science "articles", mostly because 99% of them are simple "copy and paste" jobs of press releases. However, since just that, i.e. copying and pasting is what all the major "science website" have been doing with a recently published press release from the Kingston University College in London about their smartest scientists "debunking" the myths about superfoods, I felt impelled to check what all the fuss was actually about.

      Let's start with the most important message first: There is no such thing as a "superfood" which will ward off all diseases and make you live forever, as long as you simply eat as much as you can and then, when your tummy is ready to explode, top that off with respective extracts and related dietary supplements. So, in this regard, there is no debating that Dr Jones, Deputy Dean at the University's Faculty of Science, Engineering and Computing, is right: Broccoli is no superfood!  It stands to reason that the same goes for blueberries, acai berries, parsley, rosemary, sage, thyme and the bazillion of other items on an ever-growing list of superfoods, which, by one way or another, continuously fails to to enlist dairy, meat, eggs and all the other "bad" foods of which you could easily argue that they are likewise "superfoods".

      Figure 2: Why do we need Caco 2 cells in the petri dish, when we do already have numerous studies on "superfoods" showing the actual rate of appearance of the purportedly active substances in the blood of both healthy human beings (top, cacao catechins; based on Hanlon. 2008) and rodents (bottom; for the purported anti-cancer molecule in sulforaphane from - you guessed it, the "unhonorable mention" from the press release, Broccoli; Mullen. 2009) after oral consumption? So, while the researchers criticism of the hilarious TEAC essays based on which snake oil vendors identify "superfood" after "superfood", may be right, their own approach appears likewise questionable and is by no means without alternatives.
      It is also correct that the researchers observed in a previous study (Chohan. 2012) that raw, cooked and cooked + pre-digested parsley, rosemary, sage and thyme exert different (much more pronounced!) anti-inflammatory effects on peripheral blood lymphocytes (PBLs) and those Caco-2 cells, of which Dr. Opara, a colleague of Dr. Jones (likewise correctly) states:
      "The Caco-2 is a single layer of cells grown in a laboratory environment that develops the characteristics and functions of the micro-villi, the tiny hair-like projections that aid efficient absorption found mainly in the small intestine.
      [...] This allows us to look at what nutrients pass through into the body and could be used to test food supplements, drugs and foodstuffs. We found that while some compounds may have a local effect in the gut itself, in terms of the rest of the body the impact could be negligible." (Kingston. 2012)
      What does yet not appear to be either logical or correct is the assumption that the absence of anti-inflammatory effects in the Caco-2 cells implies that systemic benefits can be ruled out. What's downright unwarranted, however is the way in which the press release generalizes these findings in the absence of experimental evidence to all polyphenols and (even more) the potential beneficial effects of whole foods, of which I hope that you, as a regular SuppVersity reader have meanwhile understood that they go well beyond those of the  individual nutrients you can extract and fill into caps, powders, tablets or gels.

      Moreover, this approach also neglects potential effects of metabolites of the polyphenols that are formed in the body’s tissues or by the colonic microflora (see Scalbert. 2000; Rechner. 2002), as well as the existing real (not cell-line, petri dish, in vitro) data on the bioavailability of many of the beneficial polyphenols, catechins, flavonoids & co from both, rodent and human studies (Manach. 2005). What on earth would be the benefit then of reviving an early 1980s technique that has been developed by the US cancer research institute, which will never be able to capture the complex interactions that are taking place during the digestion absorption and subsequent metabolism of these molecules?





      Exercise, cortisol, stress, IGF-1, BDNF, depression and cognitive impairment Sounds pretty damn complicated, right? If you add one and two together, or, in this case, very recent studies from the University of Hong Kong, the Vrije Universiteit in Brussel (Belgium) and the University of Heidelberg in Germany, the picture that emerges is actually pretty straight forward.

      Figure 1: The difference between acute (~7days) and chronic (>21days) stress (in form of exogenous cortisol) does also reflect in the voluntary running distance. The initial motivating / ergogenic effects of cortisol begin to show their ugly face after roughly 3 weeks, though and it is likely that a continuation of the study would have put the rodents in a state similar to what is commonly labeled as "chronic fatigue" (based on Yau. 2012)
      In their study, the results of which have just been published in the October issue of Neuroscience, the Chinese researchers report that acute (5-days) exposure to stress (here in the form of daily cortisol injections) exerts beneficial effects on both, the expression of the brain-derived neurotropic factor, as well as corresponding improvements in spatial learning, without altered cell proliferation compared to vehicle treatment. Chronic exposure to cortisol for 28 days in a row, however, decreased circulating and hippocampal BDNF and IGF-1 levels and lead to significant reductions in spatial learning, which were ameliorated, when the rodents had free access to running wheels.

      In that it's noteworthy that the distance the animals covered also reflects the diametrically opposed (i.e. empowering vs. draining) effects of stress with initially higher (acute cortisol phase) activity rates and a profound lack of drive towards the end of the 27day study period.

      That said, it appears likely that the protective effects of exercise would also begin to wear off with longer periods of chronic stress exposure; a hypothesis, by the way, which should remind you of the last installments of the (Female) Athletes Triad Series and the "vicious circle of overtraining, overdieting and overstressing".

      As sarcastic as it may sound (and actually is), China would be the ideal place to study the long- and short-term consequences of air pollution on brain and overall health from childhood to (premature?) death
      Now lastly, the Belgian study by Bos et al. adds yet another factor to the BDNF <=> cognition <=> exercise equation that may not be relevant for rodents, but could provide another incentive for you to incorporate regular, yet not overly taxing exercise and physical activity in general into your everyday life: Air pollution!

      It has already been established that healthy children and young adults who have been exposed to particle matter from polluted air, show deposits of ultra-fine particles (UFP) in the olfactory bulb neurons. These depositions are accompanied by neuroinflammation, the disruption of the blood–brain barrier (read more about the latter in the SuppVersity Facebook News), and an early accumulation of amyloid β42 and α-synuclein (Calderón-Garcidueñas. 2008 & 20012).

      Similar associations between living in a polluted environment with high particle matter concentrations and cognitive decline have been reported by other scientists, as well (Chen and Schwartz. 2009; Ranft. 2009; Suglia. 2008). Now the novel result in Bos et al.'s experiment is that even under those conditions, exercise can increase the otherwise successively suppressed hippocampal expression of BDNF and thus antagonize, or at least ameliarate some of the negative effects of environmental pollution (Bos. 2012)

      You have read about the somewhat questionable use of colostrum as a muscle building IGF-1 booster before, but intranasal IGF-1 as a means to treat depression? That's news, right?
      To finally come full circle, we do now only have to link these negative effects of air pollution on BDNF, the counter-intuitive circle of stress, cognitive abilities, exercise, the (female) athlete triad, BDNF and air pollution with the high correlation of daily emergency department visits for depression and air pollution Szyskowicz et al. observed in 2009 (Szyszkowicz. 2009) and the recently proposed necessity of adequate IGF-1 levels (as you know those are rock bottom in people suffering from the athlete triad) for BDNF to be able to exert its antidepressive effects, properly, and their suggestion to simply bump those up, with intranasal IGF-I so that you would have a novel, "plausible and promising treatment option of depression" (Paslakis. 2012).





      Figure 3: The effects 0.05% piperine had on the fatty acid metabolism and storage of the HFD group was so pronounced that they ended up with a better visceral fat / body weight ratio than their peers in the control group (Jwa. 2012)
      Piperine will get you lean This does not simply rhyme, according to a very recent study from the Yonsei University in Seoul, it could also be true (Jwa. 2012). At least in the rodent study Jwa et al. conducted in order to check, whether their promising in-vitro data would translate from the petri dish into the "real world" of a rodent cage, the addtion of 0.05% piperine to the chow of mice that were kept on a hypercaloric high fat diet did not just "markedly decrease LXRα mRNA expression and its lipogenic target genes (i.e., SREBP1c, ChREBPα, FAS, and CD36)" (check out figure 1 for the real world consequences of these epigenetic changes), it also lead to statistically highly significant reductions in plasma insulin and glucose concentrations, while concomitantly increasing the insulin sensitivity of the rodents.
      "In addition, piperine downregulated the expression of genes involved in ER stress, including GRP78, activating transcription factor 6, and eukaryotic translation initiation factor 2α, and upregulated GLUT2 translocation from the cytosol to the plasma membrane in the livers of PSD mice." (Jwa. 2012)
      In conjunction with the aforementioned epigenetic reprogramming of genes that are involved in the oxidation (upregulated) and formation (downregulated) of lipids, piperine's modulatory effect on the liver X receptor α  (LXRα) expression does thus entail a bi-variate anti obesity / metabolic syndrome effect that counters both of the two hall-mark features of diet-induced metabolic derangements: high blood glucose levels and lipid accumulation.

      That I would still like to see human data on the efficacy and safety of this approach is yet not the least related to previous research which suggests that piperine does not just mess around with the cytochrome P450 enzymatic cascade (among others with the enzyme that is also responsible to clear estrogen from the body), which is by the way also the most likely explanation that bioperine "improves the bioavailability" of all sorts of supplements - it simply hampers their metabolism and subsequent excretion (Najar. 2011)





      In the minutes up to the orgasm "excitement" spreads in a chain reaction from the genital sensory cortex all over the brain (img whatsonxiamen)
      Female orgasm? What's it good for, I mean "biologically" ;-) Probably some of you will have heard the SuppVersity Science News Round Up which broached the issue of anorgasmia (=inability to get an orgasm) in women. Now, while it is pretty much indisputable and straight forward that those women who are affected by this condition are missing out with respect to the literal climax of sexual intercourse, the potential biological consequences are actually less obvious.

      In a recent article in The Science in Society Review, Claire Wilson points out that due to the complexity and the fact that it cannot be empirically measured, scientists have always been wondering, why the female orgasm even exists, "as its evolutionary significance is unclear compared with the male orgasm’s explicit connection to reproduction." Among the more prominent theories are among others:
      • the evolutionary / physiological "byproduct" theory
      • the socio(-evolutionary) "cryptic choice" theory and 
      • the (bio-)mechanistic "sperm upsuck" theory
      From a mere mechanistic perspective, the latter, i.e. the proposal that the "uterine contractions may cause the cervix to lower into the seminal pool, resolving the obstacles against sperm transport posed by vaginal tenting" certainly appears to be most straight forward, as the actual orgasm is in fact accompanied by powerful striated muscles that surround the vagina producing rhythmic contractions in 0.8s intervals.

      Video 1: Meg Ryan aka Sally in When Harry Meets Sally is not just an example of an evolutionary nonsensical orgasm. The popularity of the scene is also testimony of how exciting (all puns intended) the topic.
      What's problematic about this theory is that according to Meston et al. some women report having experienced an orgasm when no contractions were observed (Meston. 2004). Moreover,
      "non-genital stimulation, dreams, hypnosis, and even mental concentration have all been shown to produce orgasm in certain women, highlighting the critical role of the brain and psychology in female sexual response." (Wilson. 2012)
      These observations would also speak against the "byproduct" theory according to which the female orgasm is just an unnecessary remnant or evolutionary "byproduct" of both sexes developing from the same embryological structure, much like how males develop nipples without any gender-specific need for them (Wallen. 2008).

      In a way likewise of evolutionary (though more socially than biologically) origin is the "cryptic choice" theory, according which regards the "females’ greater difficulty in achieving orgasm" as an incentive "for taking multiple mates among pre-human ancestors" thus promoting the confusion over their offspring’s biological sires and consequently entrusting their care to the whole of the society (Thornhill. 1996). Others argue that unreliable orgasms may bond females to those males capable of eliciting
      "Many 'cryptic choice' theorists furthermore believe that the inconspicuous nature of the female orgasm may aid in selecting which partners’ sperm make it to the egg. For instance, one study found that males’ body symmetry - a trait indicative of stable genes - predicted frequency of orgasm in their female partners." (Wilson. 2012)
      "I think women rule the world and that no man has ever done anything that a woman either hasn't allowed him to do or encouraged him to do."
      -Bob Dylan
      Yet whatever the exact "reason" (if you can even talk about that in this context) of the female orgasm may be, in the end, it is just as Claire Wilson states: "The male sex drive may have played the major role in ensuring that future generations exist, female psychology may have had a major role in deciding what they are like." (Wilson. 2012) Why does that sound to me much like what Bob Dylan once said about the relation between men and women (see box on the right)?




      Video 2: TAFE NSW video tutorial on how to measure the sub-scapular skinfold thickness. I guess it is obvious that you can hardly do that without the help of someone else ;-)
      What skinfold thickness tells you about insulin resistance in adolescents was at the center of the statistical analysis O.Yaw Addo, Mark A. Pereira and John Hime ran on a subset of the cross-sectional data of 1496 adolescents (age 12.0–17.99y) from the US national health and nutrition examination survey (NHANES) cycles 2001–04.

      According to their results, simply measuring the subscapular skinfold thickness (SF technique; see video 2 for how it's done) could provide an as reliable indicator of high risk of being / developing insulin resistance as an expensive X-ray absorptiometry (DXA) based body fat analysis (DTF technique):
      "When the top quintiles of predicted HOMA-IR values from the SF and DTF models were
      crosstabulated to identify adolescents at highest risk of insulin resistance, the exact agreement (efficiency) exceeded 92% in both sexes. Therefore, both in terms of estimating fatness-related contributions to measured HOMA and also in identifying those at most risk of insulin resistance, subscapular and triceps skinfold thickness compared well with DXA total body fat as estimators of insulin resistance in adolescents." (Addo. 2012)
      While statistically non-significant, the skinfold method was even more precise than the DXA scans in view of it's prognostic value as a tool for estimating continuous HOMA IR with adiposity measures.
      Compared to the group average, each 1 millimeter increase in subscapular skinfold thickness was associated with a ~1.5% increase in HOMA-IR in boys and girls.
      Another interesting side-finding of the study was that after a transient rise during puberty the average HOMA-IR (by the way a measure of long-term blood sugar levels) returned to pre-pubescent in many of the adolescents. The effect was most pronounced in boys and showed a high interaction with the pubertal increase in body height.




      NOPE + EGCG for practical diet help instead of overhyped fat burner!? I know that sticking to a diet and simply giving it time to do its magic does not sound half as sexy as taking the blue, red, yellow or whatever pill and shedding 4kg of pure fat within two weeks while you simply continue to eat the same junk that has made you obese in the first place, but the reality is - there is no such pill on the market and the one non-OTC "pill" I could think of that could do just that is toxic, has been used to produce ammunition in the first world war and will literally have you melt away.

      NOPE, no idea what that is? The acronym stands for N- oleoyl- phophatidyl-ethanolamine, a naturally occurring phospholipid found in animal (fish) and vegetable (cereals, soy) food that is hydrolyzed into N-oleyl-ethanolamide (NOE) and phosphatidic acid when during the digestive process. The former of these, i.e. NOE has an inhibitory effect on the expression of the endocannbinoid anandamide (N- arachidonyl- ethanolamine). The latter leads to an increase in appetite and, consequently, an intake of food (Fu. 2003). In rats, an intra-peritoneal injection of NOE has been shown to promote an anorexic effect through the activation of several intestinal receptors, which signal the brain center to reduce food intake (Broccalli. 2005).
      With N-oleoyl-phophatidyl-ethanolamine which occurs naturally in various animal and vegetable foods, and EGCG, of which I guess that all of you know that it stands for the unpronounceable green tea constiutent epigallocatechin gallate, Chemi Nutra, the manufacturer of PhosphoLean™ promises to have found a natural alternative that will help you by making it easier for you to stick to your diet.

      And in fact, if we assume that the  40 mg of NOPE, 35 mg of EGCG and 25 mg of mixed phospholipids each serving of those pills contains, will have the same effect on you, as it had on the 50 healthy, but obese adults (35 female, 15 male; 32.7 ± 13.7 years; BMI = 33.4 ± 6.2; 43.2 ± 7.2% Body Fat), you will feel
      • more relaxed instead of more tense*,
      • happier instead of more depressed,
      • less angry instead of angrier,
      • much more vigorous instead of exhausted*, and
      • less confused instead of jazzed
      while you are dieting. Unfortunately, those inter-group differences, which were evaluated by questionnaires were statistically significant only for those parameters I marked with an asterisk (*). Moreover, the purported psychological edge translated directly into a higher compliance, for the first four weeks only. It is therefore not very surprising that the overall changes in body composition in response to 8 weeks of -500 kcal or 30% (maximum of 1000 kcal) reduction in caloric intake and voluntary exercise (subjects were "encouraged to exercise 30 minutes per day, three times per week") were not significantly different.

      The fact that there was a trend towards greater improvements in body composition in the placebo group, however, is surprising. So surprising, in fact, that it made me take a look at the funding of the study: "This study was supported by a grant from Chemi Nutra, White Bear Lake, MN" (Mangine. 2012) - must be coincidence that the researchers didn't mention this trend, right?





      That's it for today, at least as far as the "On Short Notice" news here at the SuppVersity are concerned. If you want more, I suggest you take a closer look at the SuppVersity Facebook Wall, as well, where you will find (among a lot of other news) infobits on ...
      • a novel Anti-Alzheimer's drug that's based on a substance those of you who have been faithfully listening to Super Human Radio, even before the SuppVersity Science Round Up  was born will be familiar with, methylene blue,
      • even more on BDNF and its role in morphine addiction, including some insightful comments by Kamal Patal, the brain behind the PAINDatabase,
      • Pycnogenol(R) not delivering on all of the promises the producers of respective products are making, but does exert somewhat unexpected protective effects against hexavalent chromium induced spermatotoxicity, and lastly
      • CAD assisted insights into the endocrine side effects of the evil metabolic byproducts of bisphenol A and the association of BPA exposure with thyroid hormone abnormalities in mothers to be and their offspring
      ... as well as the handful of additional items I am probably going to post in the course of the next 24h before the third installment of the SuppVersity Athletes Triad Series will provide you with novel reading material ;-)


      References:
      • Bailey SJ, Winyard P, Vanhatalo A, Blackwell JR, Dimenna FJ, Wilkerson DP, Tarr J, Benjamin N, Jones AM. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Appl Physiol 2009: 107: 1144–1155.
      • Bos I, De Boever P, Int Panis L, Sarre S, Meeusen R. Negative effects of ultrafine particle exposure during forced exercise on the expression of Brain-Derived Neurotrophic Factor in the hippocampus of rats. Neuroscience. 2012 Oct 25;223:131-9.
      • Broccali GBM, Pistolesi E, Cestaro B: N-oleoylphosphatidylethanolamine reduces food intake and body weight of dietary obese rats ameliorating their antioxidant status. Gazzeta Medica Italiana Archivo Per Le Scienze Mediche 2005, 164:101–107.
      • Calderón-Garcidueñas L, Solt AC, Henríquez-Roldán C, Torres-Jardón R, Nuse B, Herritt L, Villarreal-Calderón R, Osnaya N, Stone I, García R, Brooks DM, González-Maciel A, Reynoso-Robles R, Delgado-Chávez R, Reed W. Long-term air pollution exposure is associated with neuroinflammation, an altered innate immune response, disruption of the blood-brain barrier, ultrafine particulate deposition, and accumulation of amyloid beta-42 and alpha-synuclein in children and young adults. Toxicol Pathol. 2008 Feb;36(2):289-310.
      • Calderón-Garcidueñas L, Kavanaugh M, Block M, D'Angiulli A, Delgado-Chávez R, Torres-Jardón R, González-Maciel A, Reynoso-Robles R, Osnaya N, Villarreal-Calderon R, Guo R, Hua Z, Zhu H, Perry G, Diaz P. Neuroinflammation, hyperphosphorylated tau, diffuse amyloid plaques, and down-regulation of the cellular prion protein in air pollution exposed children and young adults. J Alzheimers Dis. 2012;28(1):93-107.
      • Chen JC, Schwartz J. Neurobehavioral effects of ambient air pollution on cognitive performance in US adults. Neurotoxicology. 2009 Mar;30(2):231-9. Epub 2008 Dec 30.
      • Chohan M, Naughton DP, Jones L, Opara EI. An investigation of the relationship between the anti-inflammatory activity, polyphenolic content, and antioxidant activities of cooked and in vitro digested culinary herbs. Oxid Med Cell Longev. 2012;2012:627843.
      • Christensen PM, Nyberg M, Bangsbo J. Influence of nitrate supplementation on VO(2) kinetics and endurance of elite cyclists. Scand J Med Sci Sports. 2012 Oct 1.
      • Fu J, Gaetani S, Oveisi F, Lo Verme J, Serrano A, Rodriguez De Fonseca F, Rosengarth A, Luecke H, Di Giacomo B, Tarzia G, Piomelli D: Oleylethanolamide regulates feeding and body weight through activation of the nuclear receptor PPAR-alpha. Nature 2003, 425:90–93.
      • Hanlon N, Coldham N, Gielbert A, Kuhnert N, Sauer MJ, King LJ, Ioannides C. Absolute bioavailability and dose-dependent pharmacokinetic behaviour of dietary doses of the chemopreventive isothiocyanate sulforaphane in rat. Br J Nutr. 2008 Mar;99(3):559-64.
      • Jwa H, Choi Y, Park UH, Um SJ, Yoon SK, Park T. Piperine, an LXRα antagonist, protects against hepatic steatosis and improves insulin signaling in mice fed a high-fat diet. Biochem Pharmacol. 2012 Sep 20. pii: S0006-2952(12)00640-5.  
      • Kingston University London. Press Release: Researchers challenge super food claims. October 01, 2012 < http://www.kingston.ac.uk/pressoffice/news/461/01-10-2012-researchers-challenge-super-food-claims.html > last accessed on October 03, 2012.
      • Lansley KE, Winyard PG, Fulford J, Vanhatalo A, Bailey SJ, Blackwell JR, Dimenna FJ, Gilchrist M, Benjamin N, Jones AM. Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study. J Appl Physiol 2011: 110: 591–600.
      • Manach C, Williamson G, Morand C, Scalbert A, Rémésy C. Bioavailability and bioefficacy of polyphenols in humans. I. Review of 97 bioavailability studies. Am J Clin Nutr. 2005 Jan;81(1 Suppl):230S-242S.
      • Mangine GT, Gonzalez AM, Wells AJ, McCormack WP, Fragala MS, Stout JR, Hoffman JR. The effect of a dietary supplement (N-oleyl-phosphatidyl-ethanolamine and epigallocatechin gallate) on dietary compliance and body fat loss in adults who are overweight: A double-blind, randomized control trial. Lipids Health Dis. 2012 Oct 4;11(1):127.
      • Meston CM, Levin RJ, Sipski ML, Hull EM, Heiman JR (2004). Women’s orgasm. Annual Review of Sex Research, 2004;15:173-257.
      • Mullen W, Borges G, Donovan JL, et al. Milk decreases urinary excretion but not plasma pharmacokinetics of cocoa flavan-3-ol metabolites in humans. Am J Clin Nutr. 2009; 89:1784–1791.
      • Najar IA, Sharma SC, Singh GD, Koul S, Gupta PN, Javed S, Johri RK. Involvement of P-glycoprotein and CYP 3A4 in the enhancement of etoposide bioavailability by a piperine analogue. Chem Biol Interact. 2011 Apr 25;190(2-3):84-90. 
      • Paslakis G, Blum WF, Deuschle M. Intranasal insulin-like growth factor I (IGF-I) as a plausible future treatment of depression. Med Hypotheses. 2012 Aug;79(2):222-5. Epub 2012 May 23.
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      • Rechner AR, Kuhnle G, Bremner P, Hubbard GP, Moore KP, Rice-Evans CA. The metabolic fate of dietary polyphenols in humans. Free Radic Biol Med. 2002 Jul 15;33(2):220-35.
      • Scalbert A, Williamson G. Dietary intake and bioavailability of polyphenols. J Nutr. 2000 Aug;130(8S Suppl):2073S-85S.
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      • Szyszkowicz M, Rowe BH, Colman I. Air pollution and daily emergency department visits for depression. Int J Occup Med Environ Health. 2009;22(4):355-62.
      • Thornhill R, Gangestad SW. Human female copulatory orgasm: a human adaptation or phylogenetic holdover. Animal Behaviour, 1996;52(4):853–855. 
      • Vanhatalo A, Bailey SJ, Blackwell JR, Dimenna FJ, Pavey TG, Wilkerson DP, Benjamin N, Winyard PG, Jones AM. Acute and chronic effects of dietary nitrate supplementation on blood pressure and the physiological responses to moderate-intensity and incremental exercise. Am J Physiol Regul Integr Comp Physiol 2010: 299: R1121–R1131.
      • Wallen K, Lloyd, EA. Clitoral variability compared with penile variability supports nonadaptation of female orgasm. Evolution & Development, 2008;10(1):1-2.
      • Wilson, C. The Mysterious Function of the Female Orgasm. The Triple Helix - A Global Forum For Science In Society. 2012; 17.
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      BDNF-Driven Athletic Brain Optimization For Wise Guys: Better Hard, Than Long, But Always Without Interruptions

      Believe it or not, a "smart" brain is not necessarily a healthy brain. Nevertheless, if Einstein had worked out regularly and lived a couple of years (better decades ;-) longer, he may have had a change to figure out the missing link between his Theory of Relativity and the Quantum Theory ;-)
      "Workout for your brain!" If you were a member of the club of sedentary couch-potato, you would probably be thinking of Dr. Kawashima or similar IQ games on one of your beloved gaming devices. As a diligent student of the SuppVersity and life-long follower of physical culture, you will yet be aware that the imperative "Work out for your brain!" has to be understood quite literally. After all, there have been dozens of studies to show how exercise benefits the brain of young and old, sick and healthy, lean and obese individuals.

      In this context scientists often measure a peptide that goes by the name brain-derived neurotrophic factor, or short BDNF, which has been recognized as an important tropic hormone in the regulation
      of neuron morphology and survival. With exercise being one of the stimuli that triggers its production BDNF it is not surprising that working out has been shown to improve cellular development and growth, exert beneficial effects on mood regulation, and cognitive functions such as learning and memory - all of these things are after all influenced by this important hormone.

      Low circulating BDNF levels, on the other hand, have been associated with a widerange of neuropsychiatric disorders including depression (Karege. 2002), bipolar disorder (Cunha. 2006), schizophrenia (Zhang. 2007) and neurodegenerative diseases (Yu. 2008). And despite the fact that a definitive causal relationship between low BDNF levels and the said pathologies has yet not been established, researchers are confirmed that elevated BDNF levels can lead to improved brain health.

      So if exercise is good, how much is optimal?

      As mentioned before, we do already know that chronic exercise training - endurance exercise in particular - will promote the production of this important neurologically active peptide, what we do not know, however, are the dosage and intensity that would yield "optimal" effects... well, I should say we did not know that until a group of researchers from the Department of Psychology, Neuroscience Program, and the Department of Health Promotion and Human Performance at the Weber State University in Odgen gave us a first glimpse on what this "optimal" dose / intensity ratio may look like.

      In their latest paper Matthew T. Schmolesky, David L. Webb and Rodney A. Hansen report the results of a study involving 45 healthy human adult males aged 18-25, who were assigned to one out of six exercise conditions that varied in both, intensity (80% or 60% of heart rate reserve, or control) and duration (20 or 40 min). To elucidate whether circadian or other effects would influence the response to the long and short vigorous and moderate intensity exercise, three subjects were excluded to serve as a sedentary control.
      Figure 1: Changes in s-BDNF levels relative to baseline (Schmolesky. 2013)
      If you discard the inter-group differences and focus on the effect size in general, first, you will notice that any type of aerobic exercise will result in significant increases in BDNF levels (30% on average). Once you look closer, it does yet become apparent that there is a non-significant tendency for higher changes in BDNF levels with higher intensities and longer durations.

      For the study at hand this implies that the Vig40 trial, in the course of which the subjects cycled for 40 min at an intensity of 80% of their maximal heart rate, yielded the greatest total increase in BDNF. If you do yet take a look at the non-significant difference to the Vig20 trial, the additional 25% increase in BDNF is paid for with an additional 20 minutes on the cycle ergometer. Now taking into account that this was still more effective than the high dose bout (40min) of moderate intensity exercise, the 20 min of vigorous exercise provide the most BDNF-bang for your bucks and should thus be considered the "optimal" training regimen to promote your brain health.

      Exercise specific news: "Bigger, Stronger, Faster: CoQ10 for Brain & Muscle. The Optimal HIIT Regimen for Fun & Fat Loss - 8s at 100% 60s Idling! Protein Power From Oats? Plus: Rest Times, Clusters, Form & Hypertrophy Training" (read more)
      "Hold on that's not optimal"... Ok, you are right, it is not just questionable, but in fact highly unlikely that the scientists actually found these 20 minutes of vigorous activity are actually the non-plus-ultra among the unlimited number of potentially BDNF-boosting exercise regimen.

      In fact, the existing bias towards higher intensities and shorter durations. Yet while this would suggest that high intensity interval training could be the true "optimum" in terms of BDNF-boosting exercise. There are as of now no human studies to support this notion and a previously published study in which the researchers tested the effects of exercise on the regeneration of axons in injured peripheral nerves clearly suggests that the BDNF response to interval training is inferior to its continuous counterpart (Wood. 2012).

      Whether these results are applicable to human beings and / or whether the 5x2min intervals the rodents in the Wood study were exposed to may have been "too much of a good thing", will yet have to be elucidated in future trials.

      References:
      • Cunha AB, Frey BN, Andreazza AC, Goi JD, Rosa AR, Gonçalves CA, Santin A, Kapczinski F. Serum brain-derived neurotrophic factor is decreased in bipolar disorder during depressive and manic episodes. Neurosci Lett. 2006 May 8;398(3):215-9.
      • Karege F, Perret G, Bondolfi G, Schwald M, Bertschy G, Aubry JM. Decreased serum brain-derived neurotrophic factor levels in major depressed patients. Psychiatry Res. 2002 Mar 15;109(2):143-8.
      • Schmolesky MT, Webb DL, Hansen RA. The Effects of Aerobic Exercise Intensity and Duration on Levels of Brain Derived Neurotrophic Factor in Healthy Men. Journal of Sports Science and Medicine. 2013. 12 [epub ahead of print]
      • Wood K, Wilhelm JC, Sabatier MJ, Liu K, Gu J, English AW. Sex differences in the effectiveness of treadmill training in enhancing axon regeneration in injured peripheral nerves. Dev Neurobiol. 2012 May;72(5):688-98.
      • Yu H, Zhang Z, Shi Y, Bai F, Xie C, Qian Y, Yuan Y, Deng L. Association study of the decreased serum BDNF concentrations in amnestic mild cognitive impairment and the Val66Met polymorphism in Chinese Han. J Clin Psychiatry. 2008 Jul;69(7):1104-11.
      • Zhang XY, Tan YL, Zhou DF, Cao LY, Wu GY, Xu Q, Shen Y, Haile CN, Kosten TA, Kosten TR. Serum BDNF levels and weight gain in schizophrenic patients on long-term treatment with antipsychotics. J Psychiatr Res. 2007 Dec;41(12):997-1004.