Saturday, July 6, 2013

Intramuscular Fat & High Energy Expenditure + Fatty Acid Oxidation. Vigorous Exercise & Feto-Protection. Genetics, Binding Proteins, Phosphorus & Low Vitamin D

Jogging or Tai Chi!? You have the choice - longevity-wise it may not make much of a difference.
20% that's the average risk reduction for all-cause mortality among those of the 61,477 Chinese men in the Shanghai Men's Health Study who practice Thai-Chi regularly.

And what's more, in view of the fact that this is hardly less than the 23% risk reduction the researchers from the Vanderbilt University School of Medicine in Nashville, Tennessee, calculated for  men who walked regularly and only 7% less than the reduction in all-cause mortality Na Wang et al. observed in regular joggers, it is also the SuppVersity Figure of the week (Wang. 2013) - a figure that's not much different for cancer and cardiovascular mortality, by the way. 

Before you go exploring your Qi and prolong your life, I'd still suggest you meditate over the other On Short Notice items for a couple of minutes ;-)

Feto-Protective Effects of Vigorous Exercise in Pregnant Women

Another interesting observation of the study at hand was that the pregnant women did perform the same amount of work during their 40 min workouts, despite the fact that they had to carry significantly more weight and were clearly disadvantaged from a kinetic point of view, theoretically that is to say.
Being pregnant should be a reason to get going, not to "slacken off". After all, the chances a women is already pre-diabetic, when she becomes pregnant is unpleasantly high already. Against that background it is certainly not a good idea to reduce your daily "exercise" from "almost zero" to "minus 1".

Recent evidence for the notion that pregnancy is a reason to exercise, not to "slacken off" comes from a soon to be published study by Michelle F. Mottola et al. who found that 40 minutes of vigorous exercise at 95% ventilatory threshold (for most active individuals that would be a fast jog) yielded significant improvements blood glucose levels and better outcomes in a subsequent glucose challenge (75 g) that was conducted after the workout -- changes of which the researchers say that they are "fetoprotective" and did not lead to adverse effects on birth outcome (Mottola. 2013).

Listen up fathers-to-be: That you should not  have your pregnant wives or girlfriends do heavy deadlifts in the gym or with the water canisters at home, does not mean that you have to featherbed them - that would be detrimental to both, your loved one and your unborn child.

Gentics, Vitamin D2, D3 and Vitamin D Binding Proteins, Phosphorus & Low Vitamin D

Figure 1: If you don't have the "standard" genes you may in fact be better off supplementing with vitamin D2 to bring your total 25OHD levels up into the >20nmol/ml zone (Nimitphong. 2013)
You still think it's all just about how much vitamin D you have? Well, at least in multiple sclerosis it is probably more important how much of it is bound to vitamin D binding protein... you did not even know that existed? Well, that's the result of too much hype and too little science, which are the main characteristics of the mainstream coverage of vitamin D.

And to get back to the important stuff: If you have MS and want to benefit from vitamin D supplementation, you should try find out what your vitamin D binding proteins are like. After all high levels of VDB did totally blunt the beneficial effects of vitamin D supplementation in a recent study from China (Yang. 2013).

Ah, talking about vitamin D, you may also be intrigued to hear that at least in the 99 women and 41 men (age, 66-96 years) who participated in a recent study from the Justus-Liebig-University in Giessen, Germany (Jungert. 2013), the nutritional intake of vitamin D showed no relation to the amount of circulating vitamin D levels (25OHD3), at all.

It is possible that the high dietary intake of phosphor plays a role in the etiology of the low vitamin D epidemic (learn more)?
And while the same was true for the average calcium intakes, the statistically significant association between the dietary intake of phosphorus and the subjects' parathyroid hormone (PTH; its logarithmic value, to be precise) in the lean study participants. In view of the fact that the levels of PTH correlate negatively with the levels of vitamin D, this should remind you of a previous SuppVersity article about the potential involvement of the overtly high amounts of phosphorus in the standard western diet (cf. "Hypothesis: Does Vitamin D 'Deficiency' Protect Us From Phosphorus Overload? 1,25OHD Production Drops By 19pg/dL With Each 1mg/dL Increase in Phosphorus" | read more...).

I am convinced... we are far from understanding how vitamin D actually works. Aside from our incomplete understanding of the role the vitamin D binding protein (e.g. is VDB like SHBG for testosterone necessary for the interaction with certain tissues, while blunting the interaction with others), our concept of its interactions with vitamin A is incomplete and the mainstream paradigm of a general antagonism simply flawed. Therefore I am confident that this was not the last mini-update on vitamin D that goes beyond the hoopla of what vitamin D is supposed to be involved in, here at the SuppVersity.

The schizophrenic effects of intramuscular fat (IMTG)

Depending on the way you aquire it, the fat "within" the muscle (intra-muscular triglycerides; IMTG) appears to have very different effects. While it is generally associated with insulin resistance in the morbidly obese (a causal effect has never been proven), it has likewise been shown to increase in response to exercise (Shaw. 2010), where it serves as a readily available endurance substrate.

Things to remember about IMTG:
(1) In lean active individuals, the IMTG pool is regularly depleted during exercise and is replenished during subsequent feeding. Supercompensation is possible.
(2) Reduced IMTG oxidation appears to contribute to the reduction in fat oxidation during exercise in sedentary individuals, where it is accompanied by the accumulation of lipid metabolites and insulin resistance in skeletal muscle.
(3) The IMTG stores are a readily available substrate during workouts.
(4) A high IMTG synthesis rate is a major determinant of IMTG content and keeps lipid metabolite concentrations low and insulin sensitivity high.
(5) IMTG synthesis rates can be increased by exercise, dietary interventions, and combined dietary and exercise interventions. (based on Shaw. 2010)
Van Loon et al. (2003) for example observed a 60% reduction in IMTG content in type 1 muscle fibers following two hours of cycling exercise performed at 60% maximum oxygen uptake (VO2max) and Shaw, Clark and Wagenmakers point out that
"the specific depletion of IMTG in type 1 muscle fibers is a consistent finding and is in line with the greater capacity for IMTG storage and fatty acid oxidation in these fibers. The use of IMTG as a fuel source does not appear to be limited to endurance exercise either, as several studies have also demonstrated a significant reduction in IMTG content after a single bout of resistance exercise." (Shaw. 2010)
Against that background, it is maybe no longer that surprising to hear that a group of Harvard researchers found that those of the overweight children in their study who did not just receive "standardized healthful lifestyle advice" for 8 weeks, but were also randomized to an in-home supervised exercise intervention exhibited increases in both fitness and intramuscular triglycerides ( McCormack. 2013).
Figure 2: Overview of some of the main results of the Harvard study (McCormack. 2013)
What I am pretty sure, though, is going to surprise you is the fact that these increases in the amount of fat in the musculature of the kids (average age 13y) showed a highly significant correlation with greater resting energy expenditure (r = 0.78, P = 0.005) and a decrease in fasting respiratory quotient (r = -0.70, P = 0.02). Or to put is simply: The more intramuscular fat, the more energy your burn sitting around and the more of this energy is going to be from fat.

Against that background, studies investigating the role of ITMG in both obesity and exercise performance begin to appear in a very different light. Let's take insulin's inhibitory effect on adipose tissue lipid oxidation, as an example. Logically you should assume that this effect was a major bummer for any endurance athlete and guzzling glucose containing drinks before or even during a workout would be stupid.

Different rules for glycogen loading and re-pletion (more on the latter)
As Shaw et al. point out in their review, this insulin-induced inhibition of adipose tissue lipolysis could yet lead to an increase in IMTG utilization that would mirror the increase in IMTG utilization seen after pharmacological suppression of adipose tissue lipolysis by Acipimox (= a special form of niacin; van Loon. 2005a, 2005b). In fact, the use of IMTG has been shown to increase ∼twofold when high-GI-index meals are eaten the day preceding exercise.

Moreover, Shinora et al. were able to show that the increase in intra-muscular lipids after a 7-day glycogen loading protocol as it is commonly used by endurance athletes increased the amount of IMTGs and bumped up the fatty acid oxidation rate by 5-6% (Shinohara. 2010)

Still much to be learned: It remains to be seen how this relates to the increases in energy expenditure the Harvard researchers just observed. What appears to be certain, though is that the common vilification of IMTG is another instance of hilarious over-generalization that does not stand the test of science.

Facebook News Round-Up

As far as the official Short News are concerned, that's it for today. If you want more, I suggest you head over to the SuppVersity Facebook Wall and check out one of the following news items that appeared in the course of the week:
  • Some supplements are for drag queens and wanna-be eunuchs, only: "Study Finds 17x Elevated Estrogen, High Progesterone + Reduced DHEA Levels in 65% of Ecdysteroid, Tribulus, Phytoestrogen, Phytosterol and/or Soy Protein Users!" (read more)
    Caffeine stops cirrhosis of the liver -- That's at least what a recent paper from the Department of Gastroenterology, Hanyang University Medical Center in Korea would suggest | read more...
  • GH is an abdominal fat annihilator -- While most of you will have seen this news already, you may want to take a peek at the additional information on the "optimal" dosing regimen, I posted, yesterday | lean more...
  • Dairy & vitamin B6 decrease, green tea & co increase homocysteine -- Good to know, yet what's even more important to know is that homocysteine is not even associated with an increased risk of CVD | read more...
  • Improved body composition w/ DHEA supplementation -- Review of RCTs w/ 1353 elderly male participants says the effects are mediated by the conversion to testosterone and estrogen | learn more...
You've digested them all? Well, in that case you've two options left: (A) You begin practicing Thai-Chi or (B) you start right into an exciting weekend... whatever your choice may be, I hope you enjoy the rest of the day and come back tomorrow for more news from the realms of nutrition, exercise and supplementation sciences.

References:
  • McCormack SE, McCarthy MA, Harrington SG, Farilla L, Hrovat MI, Systrom DM, Thomas BJ, Torriani M, McInnis K, Grinspoon SK, Fleischman A. Effects of exercise and lifestyle modification on fitness, insulin resistance, skeletal muscle oxidative phosphorylation and intramyocellular lipid content in obese children and adolescents. Pediatr Obes. 2013 Jun 25
  • Mottola MF, Inglis S, Brun CR, Hammond JA. Physiological and metabolic responses of late pregnant women to 40 minutes of steady-state exercise followed by an oral glucose tolerance perturbation. J Appl Physiol jap.00487.2013; published ahead of print June 27, 2013.
  • Nimitphong H, Saetung S, Chanprasertyotin S, Chailurkit LO, Ongphiphadhanakul B. Changes in circulating 25-hydroxyvitamin D according to vitamin D binding protein genotypes after vitamin D₃ or D₂ supplementation. Nutr J. 2013 Apr 4;12:39.
  • Shaw CS, Clark J, Wagenmakers AJ. The effect of exercise and nutrition on intramuscular fat metabolism and insulin sensitivity. Annu Rev Nutr. 2010 Aug 21;30:13-34. 
  • Shinohara A, Takakura J, Yamane A, Suzuki M. Effect of the classic 1-week glycogen-loading regimen on fat-loading in rats and humans. J Nutr Sci Vitaminol (Tokyo). 2010;56(5):299-304.
  • van Loon LJ, Koopman R, Stegen JH, Wagenmakers AJ, Keizer HA, Saris WH. Intramyocellular lipids form an important substrate source during moderate intensity exercise in endurance-trained males in a fasted state..J. Physiol. 2003. 553:611–25.
  • van Loon LJ, Manders RJ, Koopman R, Kaastra B, Stegen JH, et al. Inhibition of adipose tissue lipolysis increases intramuscular lipid use in type 2 diabetic patients. Diabetologia. 2005a, 48:2097–107.
  • van Loon LJ, Thomason-Hughes M, Constantin-Teodosiu D, Koopman R, Greenhaff PL, et al. Inhibition of adipose tissue lipolysis increases intramuscular lipid and glycogen use in vivo in humans. Am. J. Physiol. Endocrinol. Metab. 2005b. 289:E482–93.
  • Wang N, Zhang X, Xiang YB, Li H, Yang G, Gao J, Zheng W, Shu XO. Associations of Tai Chi, Walking, and Jogging With Mortality in Chinese Men. Am J Epidemiol. 2013 Jun 27. [Epub ahead of print]
  • Yang M, Qin Z, Zhu Y, Li Y, Qin Y, Jing Y, Liu S. Vitamin D-binding protein in cerebrospinal fluid is associated with multiple sclerosis progression. Mol Neurobiol. 2013 Jun;47(3):946-56.

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