Vitamin K for Healthy Bones & a Lean Physique: Rat Study Finds Phylloquinone (K1) & Menaquinone (K2) Ward off Fat Gain and Cut Triglycerides by Half

Until not too long ago, scientists thought vitamin D was all about bone. Every follower of this blog knows that this is a way too narrow perspective on what turned out to be more of a hormone than a vitamin. A recent study (Sogabe. 2011) on the effects of vitamin K supplementation in mice does now suggest that vitamin D's "cofactors" phylloquinone (PK, vitamin K1) and menaquinone-4 (MK-4, vitamin K2) have been similarly mistaken.

Figure 1: Weight of visceral fat pad in g after 85 days of  phylloquinone (PK, vitamin K1) or menaquinone-4 (MK-4, vitamin K2) supplementation (Sogabe. 2011)

Japanese scientists, who wanted to investigate the effect of 85 days of vitamin K supplementation (PK: 600 mg/kg; MK-4: 600 mg/kg) on bone development in mice, were surprised to find that vitamin K did not only improve bone mass and structure, but that...

the addition of PK or MK-4 significantly decreased the total fat accumulation (p < 0.01 and p < 0.05, respectively), and serum triglycerides were reduced by 48% in the PK group and 29% in the MK group compared with the control.

This is an interesting result, which is not related to increases in growth hormone release, as one might expect in view of the bone-building effects of vitamin K. The scientists speculate: "The effect of vitamin K on fat mass could be mediated through adiponectin regulation which itself has been found to be associated with fat mass." This, as well as the dose response relationship (the human equivalence dose for the amount of PK and MK-4 used in the study would be about 7.5g!) warrant further investigation - and, as always, the SuppVersity is the place to read about it, first!

Glycogen-Depleted Athletes may Benefit from 0.3g/kg BCAA Supplementation: Improved Endurance & Lipid Oxidation

If you have ever read up on the general recommendations concerning "cardio on an empty stomach" you will most likely have encountered the advice to supplement with branched-chained amino acids (BCAA) before or in the course of the workout. I have always considered this to be a solid advice, up to now, I had yet not seen a study underpinning the common sense reasoning behind the suggestion.

Now, Gualano et al. (Gualano. 2011) published a study that investigated the effect of BCAA supplementation on exercise performance and energy metabolism in glycogen-depleted athletes (let's assume by now that an athlete following a low carb diet is in fact glycogen-depleted when he wakes up). In a double-blind placebo controlled fashion the scientists provided their subjects with either 0.3g/kg BCAA or placebo for 3 days...

On the second day, subjects were submitted to an exercise-induced glycogen depletion protocol. They then performed an exhaustive exercise test on the third day, after which time to exhaustion, respiratory exchange ratio (RER), plasma glucose, free fatty acids (FFA), blood ketones and lactate were determined. BCAA supplementation promoted a greater resistance to fatigue when compared to the placebo (+17.2%). Moreover, subjects supplemented with BCAA showed reduced RER and higher plasma glucose levels during the exhaustive exercise test.

For all of you who are now asking themselves, what validates the claim of increased fatty acid oxidation, its the reduced respiratory exchange ratio. Although its arguable how reliable a measure the ratio between O2 in and CO2 out is in terms of fatty acid metabolism, these results support the hypothesis and real world observation that BCAA-supplemented cardio on an empty stomach reliably promotes fat loss.

Grass-Fed Beef: Does CLA make the difference? Probably Not.

You certainly have heard of the benefits of the meat of grass-fed, i.e. naturally nourished, cows. Well, although I do not want to question its general superiority to corn-fed high omega-6 meat, it probably is not the CLA content which distinguishes good from not so good meat sources.

A recent study, which was conducted by scientists from the Iowa State University (Brown. 2011), scientists investigated the effect of a "balanced nutritionally complete diet" (31% energy from lipid, 13% from protein, and 54% from carbohydrate) with either high (1.17 g/d) or low (0.35 g/d) CLA content on various health parameters of 18 healthy women aged between 20 to 39 years over a 8 weeks period. These are the results:

The CLA diet did not result in any differences in insulin sensitivity, body composition, circulating blood lipids, or other measured disease risk factors as compared with the control diet.

Accordingly, the scientists concluded "that a diet naturally enriched with over a 3-fold increase in CLA from pasture-fed cattle "did not provide a health benefit when compared to "a similar diet composed of foods from grain-fed cattle."

While these results stand in line with the generally equivocal findings on possible health benefits from CLA supplementation in human beings, it remains questionable whether with a "nutritionally less complete [from a government standpoint]" diet, i.e. a diet with less carbohydrate content and a consequently higher meat consumption, the results would not have been totally different.

Figure 1: Fatty acid composition of grass-fed vs. conventional meats.

All that aside, a study by Irish scientists (McAfee. 2011) showed that the CLA content of grass-fed vs. conventional meat is not all that different, anyway. According to McAfee et al. it is rather the n-3 PUFA content of grass fed meat which "can significantly increase consumer plasma and platelet LC n-3 PUFA status" and may thus have a positive influence on metabolic risk factors in general and n-6 to n-3 PUFA ratio in particular.

Macronutrient Ratio of a Meal does not Impact Psychological and Physiological Stress Response

Many people say: "I need my carbs to relax!" But is it actually true that high-carb meals facilitate better stress management? According to a recently published study (Lemmens. 2011) this claim belongs to the realms of nutritional mysticism - at least in the short run.

Subjects (n = 38, 19m/19f, age = 25±9 yrs, BMI = 25.0±3.3 kg/m²) reported to the lab fasted and ingested either a high-carb (-C) or a high-protein (-P) meal before half of them performed a computer based stress test (S-), while the other half served as a "rested" control (R-). Groups were changed and the procedure was repeated.

Figure 1: Salivary cortisol concentrations (mean±SEM) at six time points (0, 30, 80, 125, 155, and 205 min) throughout the four test sessions: rest-carbohydrate (RC), stress-carbohydrate (SC), rest-protein (RP), stress-protein (SP); for men (n = 19, M) and women (n = 19, F). (Lemmens. 2011)

As the measured salivary cortisol levels in figure 1 show the stress response does not depend on the macronutrient composition of the previous meal. Thus, after all, another holdout of the supporters of high carb diets starts to falter.

To be fair, one must however say that the picture might have been a different one if the "stressor" had been an intense weight bearing or endurance exercise. Exercise induced hypoglycemia, for example, would unquestionably have induced a significant amount of cortisol release. Yet, my personal experience tells me that you generally do not run out of fuel if you follow a consequent low carb diet. I tend to run into problems (hypoglycemia) only, when I overdo on carbs - a consequent low carb diet, on the other hand, provides me with a steady stream of energy.

3g BCAA + Arginine + Carbs Pre-Workout Modulates Hormonal Response to Single Bout of Treadmill Running to Exhaustion

BCAAs + Arginine + Carbohydrates before workout!? Sounds familiar, doesn't it? In fact many of the first generation preworkout products were either formulated like that or consumers were advised to stack them with a branched amino acid (BCAA) product of the same company. Studies which investigated the combined ergogenic effect of these nutrients are yet scarce. So, I thought that it would be worth posting the results of a recent study from China (Hsu. 2011).

Before they started exercising on a treadmill, the subjects, 14 male physical active college students, received a beverage containing either 3g of BCAA (2:1:1) + 0.5g Arginine + 12.1g carbohydrates or placebo. Blood samples of each subject were collected before exercise, 0, 10, 20, 40, 60, 120 min and 24 h after exercise and the procedure was repeated after two weeks (cross-over design). The results were as follows:

No significant differences in the levels of lactate, ammonia, creatine kinase and glycerol between the two groups were observed at any of the time points. However, the levels of glucose and insulin were significantly higher in the BA trial as compared to those in the PL trial at the 40 and 60 min recovery points. Furthermore, the testosterone to cortisol ratio at the 120 min recovery point was significantly higher in the BA trial as compared to that in the PL trial.

While higher glucose and insulin levels are hardly surprising in view of the fact that the placebo contained no calories whatsoever, the improved hormonal recovery (measured as testosterone / cortisol ratio) in the supplemented group appears to be pretty interesting.

A closer look at the exact data does yet reveal that the supplemented group had a higher testosterone / cortisol ratio to begin with. So, if we calculate the relative changes in the T/C ratio 120min after exercising to exhaustion, these are +13.2% in the placebo group and only +6.8% in the supplemented group.
Does that mean that the money you are spending on preworkout products is wasted? From a hormonal perspective, maybe. From a psychological perspective, we do yet still have another result of the study: "Fatigue score increased immediately at exhaustion in both groups, but the decrease in the fatigue score at 120 min recovery point was significant only in BA trial." Consequently, even if it does not improve the hormonal milieu in the early recovery period, supplementation with branched chain amino acids, arginine and carbohydrates could provide the psychological edge you need to drag yourself to the gym regularly ;-)

On a side note: It would have been interesting to see T/C levels measured beyond the 120 minutes post exhaustion. Based on the fact that the recovery of the T/C levels of the supplemented group sped up from T=60min to T=120min, one may well hypothesize that there would be measurable (hormonal) advantages for the BA group at T=180min and beyond.

L-Citrulline Improves Sexual Performance: 50% Chance of Improvement with just 1.5g/day

You probably receive the same amount of daily spam mails trying to refer you to dubious viagra retailers somewhere on the Cayman Islands, or wherever else in the world. In case, you ever even thought about ordering stuff like that, you may as well consider getting some l-citrulline from your local supplement store first.

Scientistsfrom the University of Foggia in Italy (Cormio. 2011) have found that supplementation with as little as 1.5g/day l-citrulline improved erection hardness in men with mild erectile dysfunction (and I always thought Italian men would not have any erection problems ;-):

Significant improvement in the EHS [erection hardness score] from 3 to 4 was reported by 2 (8.3%) of the 24 men when taking the placebo and 12 (50%) of the 24 men when taking L-citrulline (P < .01). The mean number of intercourses per month, a nonvalidated patient-reported outcome we have commonly used in patients treated for ED, was 1.37 ± 0.93 at baseline, 1.53 ± 1.00 at the end of the placebo phase (P = .57), and 2.3 ± 1.37 at the end of the treatment phase (P < .01). For treatment satisfaction, all 12 patients reporting an EHS improvement from 3 to 4 scored very satisfied, and the remaining 12 scored not satisfied and all asked for a PDE-5 inhibitor prescription at the end of the study phase. Finally, no AEs [adverse events] occurred.

So, this is a 50% chance of improvement. In view of the price of l-citrulline (as bulk-powder) it would be worth a try. I promise, I won't tell anyone ;-)

A Natural Cure for Obesity and Insulin Resistance!? Promising Results from Animal Experiments with Bitter Melon Bioactives

In a very recent investigation, researchers from the Pennington Biomedical Research Center (Wang. 2011) found that high-fat diet fed mice gained less weight and had less compromised insulin response, if they received an (unfortunately) unspecified amount of an aquaeus extract from bitter melon:

Body weight, plasma glucose, insulin, leptin levels and HOMA-IR values were significantly lower in the BM-fed HFD group when compared to the HFD group. BM supplementation significantly increased IRS-2, IR β, PI 3K and GLUT4 protein abundance in skeletal muscle, as well as phosphorylation of IRS-1, Akt1 and Akt2 when compared with HFD (P<.05 and P<.01). BM also significantly reduced muscle lipid content in the HFD mice. BM extract greatly increased glucose uptake and enhanced insulin signaling in L6 myotubes. 

There is however two major caveat to these findings. Firstly, mice ain't a particularly good model for predictions concerning the effect of supplements that are added to a high fat diet. And secondly, even if we would see similar results in human beings, the most obvious conclusion one MUST (but obviously nobody does) draw from the results of this study is that without supplementation the low fat diet, i.e. the group of mice that consumed a diet that is appropriate to their genetic make-up, gained the least amount of weight, had the lowest leptin levels and the best insulin sensitivity.

Figure 1: Insulin levels of the mice on a low fat diet (LFD), a high fat diet (HFD) and a high fat diet supplemented with bitter melon extract (BM)

Does this tell you that you should revert to a low fat diet? No, at least not if you ain't a mouse. What it should tell you, however, is that revamping your diet, making correct food choices and eating according to what our bodies are made for is the key to health and long jeopardy - the "natural cure for obesity and insulin resistance", it's already out there. Don't even think about dietary supplements before you've got that in check...