Are There Pro-Oxidant, Cytotoxic and DNA-Damaging Anti-Oxidants in Your Supplements? Not all Forms of Vitamin C and Vitamin A are Equally "Harmless"!

Image 1: The common believe that you could not satisfy your micro-nutrient requirements without the use of a daily multi-vitamin flushes >8 billion US$ into the coffers of the industry.

I assume just one of the consumers who spent about >8 billion dollars in total for multi-vitamins each year (Balluz. 2000), aren't you? Now, tell me: Did it ever occur to you that some of those cheap vitamins, which are meant to provide you with all the vital nutrients you are supposed to be missing, because you are eating pizza, pasta and burgers instead of real food, could actually be killing your cells and damaging your DNA? In case you haven't I suggest you read on and take a look at the results of a recently published study by Therese Bergström, Jan Bergmann and Lennart Möller from the Department of Biosciences and Nutrition in Huddinge, Sweden (Bergström. 2011).

Before we get to the details, I want you to to go and take a look at the bottle of the multivitamin (or multiple vitamin products) in your supplement stash... ok, look at the label - what does it say? I suppose somewhere on the top you will find both Vitamin A and vitamin C listed, maybe even with the adjunct "antioxidants". If you bought one of the higher quality products it will probably also say "from..." followed by the specific type of vitamin A or C used in your product - usually this is hardly legible, so you better have your magnifying glass at hand ;-) If you bought your supplement in Europe, you could find one of the following ingredients there:

Figure 1: Compounds permitted in supplements by the European Parliament’s directives 2002/46/EC (EU. 2002)

Strange, isn't? While most people have been indoctrinated to believe that beta-carotene was the "better", "healthier" and "safer" alternative to "real vitamin A", few know that there are three different forms of preformed, i.e. "real" vitamin A, and even fewer people are aware of the broad range of vitamins C that can be used in dietary supplements according to the European Parliament and Council’s directive 2002/46/EC.

Image 2: Partly apoptotic HL-60 cells
under the microscope (img.
avemar.world-cancer.net)

Why leukemia cells? It is certainly a valid question to ask, why the researchers used leukemia cells in this trial, although their intention was not to investigate desirable cytotoxic effects of high dose anti-oxidants on cancer cells, but to find out whether or not high doses of commonly used dietary supplements could exhibit undesirable cytotoxic, pro-oxidant and DNA-damaging side-effects. The reason is pretty simple a a typical example of how counter-intuitive science can be: Those cells are simply and easily available and highly versatile and standardized(!) model for studying the molecular events of myeloid differentiation and the effects of physiologic, pharmacologic, and virologic elements on this process. Asking "why HL-60" is thus similar to asking "why rats" - convenience and conventionalism!

A similar ignorance exists towards the possible pro-oxidant and cytotoxic effects of those "vital" nutrients, everyone believes he would be deficient in, if he did not pop one of those high dosed vitamin preperations on a daily basis - better safe than sorry, no? According to the results of the study at hand, that largely depends on a) how high-dosed your vitamin supplement really is, and b) on which form of the antioxidants the manufacturer of your supplement has used (and you bet that you get what you pay for ;-)

Figure 2: Cytotoxicity [in % of non-viable cells] of vitamin A compounds on the viability of HL-60 cells after 24-h exposure at a concentration of 20µM; each bar represents the average of a minimum of four independent experiments; * p<0.001 (data adapted from Bergström. 2011).

As far as its cytotoxity is concerned retinal certainly stands out (cf. figure 2). Of the five tested vitamin A compounds, retinal was the only one with literally sure-fire cytotoxic effects (94%; p<0.001!) on HL-60 cells after 24h of incubation at 10 times the normal plasma concentration of retinol (2µM; cf. Zemplini. 2007). Unfortunately, that does not mean that the other vitamins A are "safe": Both, plain retinal and retinol at physiological concentrations of 2µM, as well as the cheap and widely used retinyl acetate at slightly super-physiological doses of 6µM did increase dG oxidation (the occurrence of 8-oxo-dG, the oxidized form of deoxyguanosine is an indicator of DNA damage) in a acetate buffer (0.03M Zn2+). Interestingly, the oxidative damage due to both retinal and retinol, but not the one caused by retinyl acetate, were significantly reduced, if, instead of the acetate buffer, a phosphate buffer was used.

Figure 3: Cytotoxicity [in % of non-viable cells] of vitamin C compounds on the viability of HL-60 cells after 24-h exposure at a concentration of 500µM (for AA6P solubility was so low that a lower dose had to be used); each bar represents the average of a minimum of four independent experiments; ** p<0.01, * p<0.05 (data adapted from Bergström. 2011).

As the data in figure 3 goes to show, at 10x the normal plasma concentration (50µM; cf. Duarte. 2005), which is basically what is supposed, but actually won't be achieved* (see red box below) by the mega-doses of vitamin C you see in recommended treatments for all sorts of ailments on various more or less reliable health-related websites, plain ascorbic acid (28%) and sodium ascorbate (28%) exhibit statistically significant cytotoxity. In case of the "buffered vitamin C" calcium ascorbate, even only 32 out of 100 promyelocytic leukemia cells (HL-60) survived the profoundly cytotoxic anti-oxidant bath.

*Note: In view of the ability of your body to clear "superfluous" vitamin C from the blood and regulate serum vitamin C levels so, that they will constantly remain in the < 200µM range, it is very unlikely that oral supplementation with whatever form of vitamin C will be actually suffice to induce cytotoxic damage to your cells (thx. to majkinetor for the heads up). On the other hand, this does also mean that you are unlikely to achieve those exorbitant levels which have been associated with the often touted active (not preventive) anti-cancer effects of vitamin C. Keeping an eye on your daily intake to maintain adequate levels is thus probably a very good idea, The use of high dose supplements (>500-1,000mg) for the average human being (including athletes) however is probably unnecessary.

My multi has one of the "toxic" vitamins in it! I will throw it away, right?

Table 1: Overview of the tested compounds and their potentially deleterious side-effects in the petri dish (Bergström. 2011)

All this may now easily sound like you have to flush your beloved vitamins down the toilette - at least, if you do not happen leukemia or any other form of cancer and wanted to use your A's and C's as a natural chemotherapy. In view of what you probably have read about "hormesis" and the general idea of balance and  moderation it would however be much wiser to...

• first, evaluate how much of each of the vitamins you are already getting from your diet - chances are this is much more than you have been made to believe (at least if you stick to a whole foods diet)
• second, select those supplements you really need and do not apply the "more helps more principle", the opposite is usually the case

In the unlikely case that you are following a whole-foods diet and still find that you are deficient in any of those vitamins you could not get by simply adding another servings of vegetables or fruit to your diet, pick the next best low dose supplement to meet your requirements.

Circadian Rhythmicity: Retinol (Vitamin A) & Caffeine and Their Effects on the Central & Peripheral Clocks of the Body

Image 1: Is it a bad idea to "wake yourself up" with a pot of coffee in the morning, I mean from a circadian rhythm perspective?

In the last installment of this series we have been dealing with breakfast. Now, if you are following the mainstream advice neither of the two subjects of this installment should actually be a staple of it. Vitamin A, in its active form, retinol, is "bad and dangerous" and only present in such "evil cholesterol laden foods" such as eggs. And since coffee will sure give you a heart attack, you better stick to your calcium fortified orange juice, a minimal amount of white water, ah.. I mean low fat "milk" (learn more about the difference between white water and milk in "Mutant Milk!? New Research Fuels the Flames on Hushed Up Concerns About Ill Health Effects of Homogenized Milk") and - of course - "healthy cereals". And while you will hardly be able to argue that skipping a breakfast like that is probably the best you can do for your health, this was the topic of the last installment, while vitamin A and caffeine, will be what this episode of the Circadian Rhythmicity Series will be all about.

Vitamin A the circadian vitamin?

Only recently (officially, at least; preliminary results have been published ahead of print in March 2012, already; cf. Golini. 2012) a group of researchers from the Multidisciplinary Institute of Biological Research San Luis (IMIBIO-SL), at the National University of San Luis in Argentina found that contrary to the peripheral clock gene expression in the liver, which does not appear to be disturbed by vitamin A deficiency (Shirai. 2006), the superordinate (=master) clock gene expression in the hippocampus of rats housed at a regular 12h-light/dark interval gets profoundly compromised, when the rodents are fed a vitamin A (retinol, not beta carotene!) deficient diet (Navigatore-Fonzo. 2012). According to Navigatore-Fonzo et al. the effects are mediated by modified temporal patterns of the retinoic acid receptor in the hippocampus, which plays an essential role in the activation of a whole set of clock-genes that, in turn, have been implicated - among others in the anti-cancer effects of vitamin A, you've read about at the SuppVersity not too long ago!

In the light of these recent results many previously observed, but not fully understood effects of vitamin A deficiency, such as the permanent memory impairments (Etchamendy. 2003) and its repeatedly suggested involvement as a signaling molecule (and as it now turns out potential zeitgeber) in physiological (synaptic plasticity, learning and memory, sleep), as well as pathological (schizophrenia, depression, Parkinson disease, and Alzheimer disease) neurological conditions (cf. Tafti. 2007).

The fact retinol availability is so tightly regulated alone tells us something about its importance

Is there a fluctuation in serum retinol levels as well or is vitamin A only a prerequesite for the circadian rhythm to function normally? With the activity level of vitamin A depending on both the availability as well as the release and binding of retinoic acid from the stores (mostly) in the liver and to the respective binding proteins, which are also produced in the liver, it is obvious that the liver is the most important regulator of vitamin A metabolism (Buzio. 1989). Maybe this is also why it is protected against circadian disturbances subsequent to vitamin A deficiency.

Unfortunately, our understanding of the exact function of the retinol binding proteins is still very limited, what we do know, however, is that their release and renal clearance show a distinct circadian rhythm which is synchronized to meal ingestion and the excretion of (Buzio. 1989). Our understanding of these mechanisms is yet still too preliminary to make any supplement recommendations besides "don't avoid the full-fat vitamin A rich foods, we have been eating for ages!". This is all the more true, since the range, within which beneficial effects can be seen is not just very narrow, but will also depend on (a) your baseline vitamin A status and (b) the way your body metabolizes dietary and supplemental vitamin A, the latter of which usually comes in the form of retinyl palmitate.

At doses in the <10,000IU/day range vitamin A is regarded as totally benign, but even doubling that dosage, which was basically what Behr et al. did for their recently published paper on the potential anti-oxidant effects of vitamin A on menopausal increases in oxidative brain damage, when they  supplemented the diets of ovariectomized rats with 1,500IU /kg retinol palmitate (human equivalent ~20,000IU) per day, can result in profound increases in cerebral oxidative damage (Behr. 2012 Jul).

In conjunction with vitamin A's beneficial effect on serum markers of oxidative damage Behr et al. had observed in a previous trial with 500IU/kg and 1,500IU/kg per day (human equivalent ~6,700IU / ~20,000IU) in the same ovariectomized rodent model of menopause (Behr. 2012 Apr), the latest results from the laboratories of the Center of Oxidative Stress Research, at the Federal University of Rio Grande do Sul in Rio Grande do Sul, Brazil, only contribute to the emerging image of the hitherto hardly understood "Dr. Jekyll and Mr. Hide nature" of the (imho) most underrated vitamin there is (sorry, for the rant, but I won't get tired of raising the awareness that retinoic acid is, contrary to its overrated cousin, "vitamin D", a "real vitamin", in the sense that it is a substance we must necessarily get from our diet, while "vitamin D" is nothing but a cholesterol metabolite we should actually be able to produce ourselves, if we just got enough dietary cholesterol and sun exposure).

Figure 1: The profound loss of the rhythmicity of clock gene expression (BMAL1, PER1, top)  subsequent to three months of a virtually retinol free diet could not be restored after only 15 days on the regular rodent chow (same as control). These changes coincide with a similar loss of / shift in the expression of the antioxidant enzymatic cascade (shown here is the GPx activity) and subsequent increases shifts (deficiency) and increases in malondeyaldehyde expression (vitamin A refed group; bottom right - based on Fonzo. 2009

A closer analysis of the expression of selected markers of antioxidant activity and oxidative damage in the brain of vitamin A deficient rodents (3 months on a virtually retinol free diet) and vitamin A replete animals, who were fed the control chow for only 15 days after the depletion phase appears to confirm some of these results (Fonzo. 2009):

As expected, temporal patterns of CAT and GPx activities observed in the rat hippocampus were consistent with the rhythm of lipoperoxidation. While the lowest CAT activity occurs during the light period and, at least in part, brings lipid peroxidation into the maximal level, highest CAT and GPx activities, practically concur with the nocturnal peak of lipoperoxidation. Thus, antioxidant enzymes would have a complementary and proper timing for protecting hippocampus against peroxides, maintaining lipoperoxidation at controlled fluctuating levels, with the lowest MDA concentration occurring during the diurnal, anabolic, period in rats [...] the location of enzymes activity peaks during the night-feeding-period, may suggest the influence of feeding cycle, and macro or micronutrients, such as proteins, carbohydrates, aspartate, glutamate or some vitamins, on those rhythms, [...] the nocturnal peaks of CAT and GPx antioxidant activity seen in the hippocampus of our control rats would be in phase with the best time for performing learning and memory tests."

In this context it is interesting to see that the peak of CAT and GPX (in figure 1, only GPx is shown) does still coincide with the nightly (remember, rats eat during the dark period!) drop in GPX activity. The daily (=sleep / low activity phase) steady decline of which Fonzo et al. state that in coincides with the variation in the expression and activity of the BMAL1:CLOCK and the PER1 protein activity with

• a peak in GPx and Cat activity following the the BMAL1 protein peak at the end-of-the-night/beginning-of-the-day in the control rats, and 
• a trough of the Cat and GPx experssion after the negative regulator, PER1 protein peaks at the end of the activity phase during the day,

on the other hand, is profoundly disturbed in the vitamin A deficient animals that present with a complete loss of the BMAL1 and PER1 rhythm (figure 1, top). It does therefore appear obvious that we are (once more) dealing with two controlling mechanism:

1. an "externally" modulated, food (in the widest sense) induced regulatory mechanism and 
2. a fundamental, time- or rather light-dependent, centrally mediated circadian rhythm 

And while the latter of the two can be partly restored by vitamin A repletion. The 15-day repletion phase in the study at hand was obviously not long enough for the GPx and lipid peroxidation levels (as measured in malondyaldehyde TBARs) to return to their pre-intervention levels. If this is, as the scientists argue a result of transcriptional changes in the vitamin A receptor (RXR) "sensitivity", it is however likely that both the GPx peak activity (which should increase) and the closely related formation of lipid oxidation byproducts (MDA) should return to baseline, as soon as the stores are fully replete and the RXR levels have recovered.

From vitamins to ergogenics, from chronic to acute, from retinol to caffeine

Contrary to the effects of vitamin A which can be stored and released whenever our bodies deem it necessary, the impact of caffeine on the circadian rhythm is by the very nature of its metabolism acute and relatively short lived. This is at least true as long as the caffeine-induced circadian shifts do not lead to permanent deteriorations of the circadian rhythm. Intuitively, we all believe that caffeine can effect the circadian rhythm (or what our mainstream understanding is telling us, the circadian rhythm would be). It's not by chance that millions (ab?)use coffee and caffeine beverages on a regular basis to get going in the morning or keep going in the evening - times when our natural, undisturbed circadian rhythm should be telling us that our bed is the place our body would prefer to be, now.

One of the more exercise specific studies on this matter comes from the Exercise Physiology Laboratory at the University of Castilla-La Mancha in Toledo, Spain, where Mora-Rodríguez and his colleagues investigated the effects of a standardized caffeine containing (6mg/kg) or caffeine-free breakfast (ingested at 9:15AM) on early morning (10:00AM) or late afternoon (18:00PM) workout performance.

Figure 2: Hormone levels, performance and catecholamine levels on AM during AM and PM training sessions with or without caffeine containing breakfast (red = AM breakfast contained 3mg/kg caffeine); * indicates significant difference to AM (Placebo), PM trials were always performed on separate days with regular breakfast (based on Mora-Rodríguez. 2012)

As the data in figure 2 goes to show the whopping dose of 225mg of caffeine (note: in the graphical summary the scientists write 6mg/kg, if this is correct and the 3mg/kg that are repeatedly being mentioned in the text, then the dosage would have been 450mg) the twelve highly resistance trained men (75kg body weight; age 20; body fat 11%) did compensate for the "early morning weakness" of the participants and increased their bench press and squat performance as well as their isokinetic leg extensor strength (not shown in figure 2) to late afternoon levels, without inducing statistically significant changes in any of the measured hormonal parameters (growth hormone, testosterone, cortisol) compared to the placebo trial.

Short-term stimulation is not (yet?) equivalent to changes in circadian rhythmicity

Hack your training, not your rhythm? If the chronic use of caffeine and other stims to increase your performance at times of the day, where your circadian rhythm does not allow for maximal performance, entails possible negative downstream effects on the regular expression of your clock-genes, why don't you just train by the clock, then? Basically this is also what Hayes et al. suggested in their 2010 paper in Chronobiology International, where they state that despite the higher testosterone levels in the morning "an increased resistance exercise-induced T response [...] in the late afternoon [would suggest a] greater responsiveness of the hypothalamo-pituitary-testicular axis" later in the day - that this is bullshit, is something you should be aware by now, as the increased expression of testosterone has, as Hayes et al. have to coincide little to no influence on the hypertrophy response to training. Rather than that, they do therefore suggest to obey to the "individual responsiveness" and train whenever you feel you perform best (without the use of stims).

At times, when this is not possible, the use of stims (esp. caffeine, which is still among the "less damaging" stimulants on the OTC market), can provide temporary relief - as soon as even  3 cups of coffee only make you sleepy it is more than high time to take a break from caffeine and high intensity training (see "Tapering & Detraining - When and How to Take a Break")

For Mora-Rodríguez et al. these observations are a clear-cut sign of "circadian rhythm effects", but are they really related to changes in circadian rhythmicity? They blunt the morning reduction in muscle performance due to circadian rhythm - there is no debating that, but the study does not provide convincing evidence that this is due to changes in the expression of zeitgeber proteins and thus a direct consequence of a shift in circadian rhythmicity. If we take another look at figure 2, we would thus expect to see similar hormonal expressions, as well. After all, both the spike in cortisol in the morning as well as the steady decline of testosterone and even steeper decline in cortisol that occurs in the course of the day are both mediated by the circadian rhythm. The adrenaline spike in response to the ingestion of caffeine, which is unquestionably responsible for the observed performance enhancing effects in the study at hand, on the other hand, has nothing to do with circadian rhythmicity.

Did I mention that results from in-vitro studies suggest that cortisol spikes, esp. the huge spike in the morning, could act as a "reset switch" for the circadian clock? (cf. Balsalobre. 2000)

If anything, we could - based on the acute catecholamine response in the Mora-Rodíguez study, that chronic morning caffeine consumption could lead to subsequent downstream changes in the expression of zeitgeber genes, which would in turn trigger a 12h shift in circadian rhythmicity with low morning and high evening cortisol levels that would basically reverse the natural pattern as it was observed in the AM/PM(Placebo) trials.That this would entail a whole host of negative health effects is something you should by now be familiar and renders the (long-term) use of caffeine to "avoid the morning reduction in muscle performance due to circadian rhythm" at least highly questionable, as it would go- in the most fundamental sense of the word - against our nature. If chronic caffeine consumption did actually induce the aforementioned changes in circadian rhythmicity. So, the next question would be...

Are the effects of caffeine even of circadian origin / does it affect circadian rhythms?

The answer to this question is not exactly easy to find, as most studies follow the flawed assumption that "being more awake" would equal "being able to hack the circadian rhythm", when it could just as well be nothing more (and nothing less) than a highly effective way to outwit the latter. Against that background it's strange that Oike et al. were the only scientists I found that explicitly mention that it "remains unknown" "whether or not [caffeine] affects mammalian circadian clocks remains unknown" (Oike. 2011).

Figure 3: The in-vitro exposure of human osteosarcoma cells (a common model used in gene essays) messes with the previously mentioned clock genes Per2 and  Bmal1 genes (left) and the in vivo ingestion of coffee / administration of caffeine in drinking water did increase the locomotor activity period length of mice after normal lighting conditions (first two weeks lower panel) and constant darkness (upper panel, right; based on Oike. 2011).

Luckily Oike at el. did not just nag at the absence of reliable evidence for / against the effects of caffeine on circadian rhythmicity, but also conducted a couple of in vitro and in vivo studies, in the course of which they were able to show that notwithstanding it's disturbing effects in on clock gene expression in the petri dish (figure 3, left), the "real-world" test with coffee and caffeine did

• lengthen the circadian rhythm of reporter gene expression in liver explants of the rodents, without affecting the time of the rhythm peak in the liver explants (not shown), while
• left the period length in the likewise explanted suprachiasmatic nuclei unchanged, but delayed the peak time of the rhythm

the real world results of these somewhat schizophrenic modulatory effect of caffeine on the peripheral (liver) and central (suprachiasmatic nucleus) rhythm is an increased length of the circadian pattern in dark-exposed (=constant day for mice!) mice, without affecting the locomotor activity in the presence of appropriate light cues!

In other words: The effects of caffeine will only mess with your circadian rhythm if they are not overridden by appropriate light cues!

Similar results have been reported by Sherman et al. who made an even more complex experiment which the results of which will be part of the next installment of this series, as the inclusion of a restricted feeding regimen a la intermittent fasting with a minimalist 3h feeding window segues quite nicely into the discussion of the metabolic implications of caffeine and nutrient (esp. glucose) availability, we will take up in the next installment of the Circadian Rhythmicity Series.

Image 2: I admit that all this is not easy to understand and many of the implications on our everyday lives are yet not clear, either. I still hope you don't feel you have wasted your valuable time with this post.

Before I let you go, I do yet still want to give you the elevator pitch on this long and allegedly very complicated post. While much of what we have been studying today must still be considered preliminary (also on the expert level) there are three important and theoretically, as well as experimentally relatively well certain take home messages. The first pertains to the importance of light cues as the main regulators of the central clock gene expression in the brain, the second relates to the vital, hence "vitamin", importance of vitamin A for the integrity of the central clock, and the third relates to the modulatory effect certain molecules, such as caffeine, can have on the peripheral clocks.

The practical implications of these insights, on the other hand are pretty straight forward and for most of you probably no real news, anyway:

1. stick to the "natural" dark/light cycle - reread episodes one and two of the series for tips on how you can make do so in our "light polluted" world
2. get adequate amounts of vitamin A in your diet - there is no need to supplement, your body manges the levels of vitamin A very effectively, so that a piece of liver once in a while is a way better choice than a vitamin pill every day
3. don't be scared of coffee - as long as you still stick to the natural cycle (see first point), your circadian rhythm may exhibit slight shift, it will yet only break if you use caffeine + light as in popping a caffeine pill and surfing on the Internet with your melatonin suppressing iPad (see episode I) in the middle of the night

Now, before you switch off your iPad and go to bed today, I suggest you check out the SuppVersity Facebook Wall, for the latest news - it is no coincidence that an item about the -57% reduced Parkinson's risk in habitual coffee drinkers who consume at least three or more cups per day, as well as a reference to the latest confirmation of the liver protecting effects of coffee there... ah, and by the way, it could be that we will be able to track those back to circadian gene expression (peripherally, obviously ;-) in the next installment, as well...

References:

• Balsalobre A, Brown SA, Marcacci L, Tronche F, Kellendonk C, Reichardt HM, et al. Resetting of circadian time in peripheral tissues by glucocorticoid signaling. Science 2000;289:2344–7
• Behr GA, Schnorr CE, Moreira JC. Increased blood oxidative stress in experimental menopause rat model: the effects of vitamin A low-dose supplementation upon antioxidant status in bilateral ovariectomized rats. Fundam Clin Pharmacol. 2012 Apr;26(2):235-49.
• Behr GA, Schnorr CE, Simões-Pires A, da Motta LL, Frey BN, Moreira JC. Increased cerebral oxidative damage and decreased antioxidant defenses in ovariectomized and sham-operated rats supplemented with vitamin A. Cell Biol Toxicol. 2012 Jul 18.  
• Buzio C, Mutti A, Capani F, Andrulli S, Perazzoli F, Alinovi R, Negro A, Rustichelli R. Circadian rhythm of proteinuria: effects of an evening meat meal. Nephrol Dial Transplant. 1989;4(4):266-70.
• Fonzo LS, Golini RS, Delgado SM, Ponce IT, Bonomi MR, Rezza IG, Gimenez MS, Anzulovich AC. Temporal patterns of lipoperoxidation and antioxidant enzymes are modified in the hippocampus of vitamin A-deficient rats. Hippocampus. 2009 Sep;19(9):869-80.
• Golini RS, Delgado SM, Navigatore Fonzo LS, Ponce IT, Lacoste MG, Anzulovich AC. Daily patterns of clock and cognition-related factors are modified in the hippocampus of vitamin A-deficient rats. Hippocampus. 2012 Aug;22(8):1720-32. 
• Hammouda O, Chtourou H, Chahed H, Ferchichi S, Chaouachi A, Kallel C, Miled A, Chamari K, Souissi N. High Intensity Exercise Affects Diurnal Variation of Some Biological Markers in Trained Subjects. Int J Sports Med. 2012 Jul 12.
• Mora-Rodríguez R, García Pallarés J, López-Samanes Á, Ortega JF, Fernández-Elías VE. Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men. PLoS One. 2012;7(4):e33807. Epub 2012 Apr 4. 
• Navigatore-Fonzo LS, Golini RL, Ponce IT, Delgado SM, Plateo-Pignatari MG, Gimenez MS, Anzulovich AC. Retinoic acid receptors move in time with the clock in the hippocampus. Effect of a vitamin-A-deficient diet. J Nutr Biochem. 2012 Aug 16.
• Oike H, Kobori M, Suzuki T, Ishida N. Caffeine lengthens circadian rhythms in mice. Biochem Biophys Res Commun. 2011 Jul 8;410(3):654-8. Epub 2011 Jun 13.
• Shirai H, Oishi K, Ishida N. Circadian expression of clock genes is maintained in the liver of Vitamin A-deficient mice. Neurosci Lett. 2006 May 1;398(1-2):69-72.
• Tafti M, Ghyselinck NB. Functional implication of the vitamin A signaling pathway in the brain. Arch Neurol. 2007 Dec;64(12):1706-11.

SuppVersity Cellulite Special: The Etiology of Cellulite, Genetical and Behavioural Risk Factors? Physical and Supplemental Treatment Strategies & Their Efficacy

This photo of a 37-year old woman some of you may already have seen Facebook testifies to the success of 12 weeks on 333U/cc retinol cream + high intensity laser pulses (Fink. 2006)

I guess, or should I say, I'd hope (?) that some of you have already been waiting eagerly for the write-up of yesterday's Special Installment of the SuppVersity Science Round-Up on the Super Human Network and all the details and obviously the supps, Carl and I could not squeeze into this 1h+ show.

Before you go over this huge (and this is also why it took me so long to post this) serving of the "Seconds", I do yet highly recommend that you download and listen to the podcast, first. You can grap the MP3, right here.  It's free and if you don't like the ads, just skip forward, but please come to terms with the fact that a daily 2h radio has to be financed one way or another!

Let's dig right into this lumpy-bumby skin condition, now!

Despite the fact that they did not identify the underlying reasons for the development of cellulite correctly, Alquier and Paviot (1920), who described cellulite as a non-inflammatory complex cellular dystrophy of the mesenchymal tissue caused by a disorder of water metabolism, which produced saturation of adjacent tissues by interstitial liquids that was brought about by a reaction to traumatic, topical, infectious or glandular stimuli, already had a pretty decent understanding of the structural characteristics of cellulite (cf. Rossi. 2000).

Figure 1: Overview of the four main stages in the development of cellulite. If you take closer look they actually reflect much of what Alquier & Paviot (1920) already suspected: a disorder in water metabolism and a complex tissue dystrophy, which can yet become inflammatory in the late stages

The fact that cellulite is nothing but the highly visible manifestation of the messed up structural grid that holds the skin (epidermis) and the underlying fat layer in place is also important in view of the fact that up to today, way too many people look at cellulite as if it was something like a transient allergic reactions you could get rid of, once you stop eating things high GI carbs or whatever the contemporary dietary villain may be.

Unfortunately, this is not the case so that Nürnber et al. are not totally off, when they write a a 1978 paper about the ..

“[…] the essential normality and inevitability of [cellulite] in women, the supervention of it in hormonally feminized men, and the near futility of treating the non-disease” (Review by Nürnberger. 1978)

It is, and this is something that was completely missing from the previously cited first description of the “disease”, in fact partly Mother Nature who is to blame for the

• abnormal hyperpolymerization of the connective tissue,
• primary alterations in the fatty tissue,
• microcirculatory alterations

with genetic and hormonal factors determining the basic risk profile and inactivity, a messed up diet, obesity, medication etc. being nothing but corroborating factors.

If you will, the X-chromosome and is myriad downstream effects that make a man a men could even be perceived as a genetic factor – a highly protective one that is.

Figure 2: Relative contribution of perpendicular, tilted and parallel septae to the "structural part" of the dermis (left; Querleux. 2002); comparison female vs. male skin (Rosenbaum. 1998), note: the comparison misses the important parallel structures esp. in the male skin, but I guess it still conveys the basic idea

As you can see in figure 2 (right), the mere fact that the upper most parts of the skin, the Epidermis and the Corium is much thicker in men than in women would already conceal major parts of the pumpy structure in a man. In women, on the other hand, the sclerotic macronodules that form during step four in the etiology of cellulite are highly visible through the “thin skin” of a woman.

Female skin with and without cellulite – what are the differences?

Figure 3: Photos of patients with grade II-IV cellulite. Mind the extreme difference between the contracted and uncontrated state in grade II (top vs. bottom; Rossi. 2002)

In addition to the general sex differences, Querleux et al. (2002) observed that women who suffer from cellulite have a 4x higher fat volume in the dermis, than normal women (note: the total amount of fat in men and women is not significantly different).

It goes without saying that this increase in volume would actually require an increase in strength or the number of stabilizing elements in the flexible structure that holds the fat, liquids and other components of the skin in place.In conjunction with the increased interstitial pressure that is a result of the microcirculatory alterations and the defect in collagen synthesis this increase in fat volume is however more than the comparatively unorganized fibrous structure of the female skin can hold.

If you think of the skin as three-dimensional grid that is filled with balls and lacks the structural components that separate the balls in the 1st row from those in the 2nd, 3rd, … etc. row, it should be obvious that any endogenously (interstitial pressure) or exogenously applied pressure (from within = muscle; or from outside = pinching) will push the balls or rather fat cells against the top-layer that's covering the grid (the uppermost parts of the skin) and cause pumps to appear at the surface.

A very similar mechanism is responsible for the appearance of the bumps and the valleys you see through the thin layer that’s covering the underlying fluid and fat-filled part of the dermis in women with cellulite.

Cold, not valsodilated & "lumpy-bumpy"

The presence of the sclerotic perpendicular macronodules in-between the pumps and dentures, only contribute to the nasty appearance and do little to maintain the structural integrity of the tissue that’s actually supposed to be pervaded by numerous small & flexible, randomly but highly crosslinked septae that keep the fat cells in place.

Figure 4: I assume you would not have needed this thermograph to tell me that cellulite ain't exactly hot ;-)

If you look at the thermograph to the right of this paragraph you will also notice that the metabolic activity of the tissue is similarly irregular and (don’t get fooled by the colors) overall much lower in women with cellulite compared to their “healthy” counterparts.

This is both a contributing factor, as well as a results of the decreased micro-circulation in the dermis (see cold green areas) and contributes to the increased water retention in the skin. The latter will increase the pressure and worsen the condition… it is a self-perpetuating viscous cycle, yet one that opens therapeutic doors not to reverse, but at least to halt the progress of the ongoing dystrophic processes.

Estrogen drives cellulite development

And while we are going to deal with the "therapeutic" options in just a minute, let's briefly recapitulate, what I said about the causes / confounding factors during yesterday's show (listen to the podcast for details):

• genes and sex - simply being a women predisposes you to develop cellulite; I know it's not fair, but that's how it is; the same goes for the genes: if your mother and grandmother had it, chances are you will develop it, as well 

• 

  Figure 5: The influence of estrogen on the pathophysiology of cellulite (Rossi. 2002); easy to see, estrogen is the motor of cellulite development

  high estrogen, low progesterone (e.g. puberty, pregnancy, birth control, PMS; partial revision in menopause possible) - estrogen (E2) increases the accumulation of fat, spec. in the areas that are typically affected by cellulite, it renders the fibroblasts more hydrophobic and predisposes to water retention and edema, it increases the permeability and thus the leakage from the cells and promotes the formation of sclerotic tissue (figure 5)
• insulin resistance / diabetes - does not only accelerate fat gain (at least as long as there is still some insulin around), but will also increase the production of glycosaminoglycans which will draw even more water into the tissue (Lotti. 1990)
• obesity (and obesogenic diets) - the faster the fat accumulates and the larger the cells become the greater the demand on the structural components of the dermis and the more likely it will give in and the bumps and start to appear (remember: cellulite is not about having too much body fat, if it is acquired slowly and you are not genetically pre-dispositioned to cellulite you can accumulate quite an amount of fat without developing cellulite)
• hypothyroidism - thyroid hormone increases hyaluronic acid and chondroitin sulphate production, low levels will thus hamper the formation and renewal of the structural parts of the dermis
• stress / corticosteroids - if you are not taking exogenous corticosteroids like prednisone, stress and high corticosteroid levels are actually identical and have similar effects as low thyroid hormone (by the way, stress, even "eu-stress" such as exercise, will also have thyroid hormone levels plummet; learn more)
• lack of exercise - decreased vasodilation, increased weight gain, increased water retention, increased risk of diabetes... I don't have to enumerate all of them, right?
• low potassium, zinc, copper and selenium intake - while the former will help your body regulate the water balance, zinc and copper are important for the formation of the net that keeps the fat in place and have, just as selenium anti-oxidant properties as part of Copper/Zinc Superoxide Dismutase
• smoking and boozing - both will promote the decline in micro-circulation

Now that you know what you cannot change and / or should not do, let's take a look at what you can do as far as physical treatments and supplements / drugs are concerned.

Currently available physical "treatment" options

I highly encourage you to also listen to the podcast, as I am going to keep this short in view of the fact that Carl went through all the items, anyway:

• Iontophoresis: Applies a galvanic current on the surface of the skin to depolarize it and alllow drugs pass through the dermis; it is also used to increase the vasomotor action (vasoconstriction, followed by vasodilation) of which practitioners of this method believe that it may have a positive effect on the compromised metabolism in cellulite skin
• Acoustic wave therapy / ultrasound: Uses high frequency vibrations, which have a thermic and vasodilator effect; is also used as an adjunct to "hammer" drugs into the skin; there is some evidence that it can provoke lipolysis and is thus used during liposculpture procedures. Russe-Wifingseder et al. reported only recently that the use of ultrasaund that acts only on the subcutaneous tissue produced "improvement in number and depth of dimples, skin firmness and texture, in shape and in reduction of circumference" (Russe-Wifingseder. 2013) in placebo-controlled trial.
• Thermotherapy: The heat is suppose to increase vasodilation. Experts say that its effectiveness is questionable, as some reports suggest that it did actually aggravated cellulite, maybe in consequent protein denaturation due to the high temperature. 
• Pressotherapy / Massage therapy: Either done by hand or with a pneumatic massager, the intention is to help the skin to release the liquid that's accumulating in the tissue and activate the venous return; it is also used to to treat lymphatic, venous or mixed oedema of the limbs, so that you can expect cosmetic effects of unknown (probably short ;-) duration
• Lymphatic drainage: While it has been used since 1936, the pumping movements using gentle and rhythmic pressures will stimulate the lymphatic flux, but have no proven and above all persistent effect on cellulite
• Laser therapy Low‐level, dual‐beam laser energy, as well as high intensity pulsed laser that are commonly used for "body-contouring" have been reported in several studies to "help" with cellulite. Most of those do yet only report reductions in subcutaneous fat and results like "increased well-being" among the particpants.
• Elecrolipophyresis: Unlike with the #1 on the list the electric current is not applied to the surface of the skin, but rather to several pairs of thin (0.3 mm) long (5–15 cm) needles which are connected to a low frequency current generator. This generates an electromagnetic field which is supposed to modify the interstitial tissue and aid in the circulatory drainage, as well as lipolytic processes. High quality evidence for its usefulness is absent.
• Mesotherapy – This is the well known injections of "solvents" into the adipose tissues. While there are various protocols available most involve phosphatidylcholine. What they all have in common is a highly questionable safety profile and the fact that they yield very ambiguous (mainly negative in peer-reviewed studies) results. Aside from that, dissolving the fat cells within an already corrupted structure is not exactly what I would deem helpful...

Before we go on to the supplements, let me briefly mention that a meta-analysis of cosmetic products marketed for cellulite reduction did show an overall effect, with respect to the thigh circumference (-0.46cm, analysis of 21 original papers; cf. Turati. 2013), while there was no consistent improvement in the nasty look of the skin.

Supplements & drugs for cellulite prevention (and reduction!?)

As mentioned on the show, most of the supplements in the following list are going to help mitigate some of the symptoms, reduce the fat load (literally) on the weak structure of improve the micro-circulation. Aside from retinol and maybe silicon, of which esp. the former appears to have a direct effect on what's going on beneath the surface of the skin, most don't hold much promise for getting rid of the underlying problems.

• 

  Suggested read: "Brown Algae Extract Reduces Body Fat Without Dieting or Exercise. Ecklonia Cava Polyphenols Help Shed Weight Even in The Presence of a Slight Caloric Surplus." | read more...

  Supplements to burn the fat - Methylxanthines (theobromine, theophylline, aminophylline, caffeine), which act through phosphodiesterase inhibition, isoproterenol and adrenaline which are beta-adrenergic agonists, and yohimbine, piperoxan, phentolamine and dihydroergotamine which are alpha-antagonists and will "encourage" the fat cells in this "stubborn fat area" to release more of the fat that's stored in them -- just pick the next best fat-burner from your local supplement story invent something that will have it pass through the stratum corneum and you got your "topical fat burner", of which I can only repeat that it will not get rid of the bumps - if anything it will reduce the severity.
  
  In view of the importance of Co-enzyme A in this process, adequate vitamin B5 and cysteine, which are used for its synthesis and maybe even carnitine, which helps to transport and burn the fat that's actually released from the fat traps on your thighs can enhance the effects of the previously mentioned agents. This is important because free fatty acids may saturate the system, leading to negative feedback of lipolysis (Di Salvo. 1995).

• 

  Suggested read: "How Working Out Changes the Morphology of Your Body Fat" | read more...

  Supplements to increase micro-circulation: Ivy and Indian chestnut extracts, ginkgo biloba and rutin, maybe pycegnol and the pharmacological agent Pentoxifylline, which is a drug commonly sold by Aventis under the brand name Trental it improves microcirculatory perfusion through its effect on haemorrheological factors, including erythrocyte shape, platelet aggregation and plasma fibrinogen concentration. While Pentoxifylline has been used to treat chronic venous insufficiency, stasis ulcers in controlled studies, its efficacy wrt to cellulite has not been proven.

• Antioxidant and immune modulatory supplements: Vitis Vinifera, borage oil, fucus. The latter is a common type of brown algae, that will also enhance the metabolism and reduce the oedema and intestinal inflammation.  

• Asiatic centella extract aka guta cola: The main reason this is a standalone is the frequency with which it is mentioned in the literature. Centella has a vegetable origin and consists of asiaticosideo (40%), madecassic acid (30%) and Asiatic acid (30%), triterpenic derivatives which act in vitro on fibroblasts, stimulating collagen and mucopolysaccharide synthesis.
  
  

  

  Chronic overtraining is no solution and the stress could in fact cause your to your cellulite problems. In addition, it is also the cause of chronic injuries, which persist even, when you finally realized that your own ambition is about to ruin your health (learn more).

  It has been used in the past both topically and systemically, and reported benefits of the oral administration route must probably be ascribed to its beneficial effects on the micro-circulation. According to Hausen (1993) it does neither lead to cutaneous hypersensitivity, nor does it have a toxic effect, when it is ingested.
  
  In a histopathological, double-blind study by Hachem & Borgoin from the late seventies it the administration of 60 mg of dry Asiatic centella extract orally once a day for 90 days brought about a significant reduction in the diameter of adipocytes in both the deltaoid and gluteofemoral regions in the patients who received centella compared to those who received placebo. Interestingly, this reduction was more apparent on the gluteofemoral region and went in hand with a decrease in interadipocyte fibrosis. 
  
  If it were not for the missing placebo control in most of the hitherto published studies, this could actually be a supplement worth trying.

• 

  Suggested read: "Evidence From the Metabolic Ward: 1.6-2.4g/kg Protein Turn Short Term Weight Loss Intervention into a Fat Loss Diet" 2x-3x higher than RDA protein intakes work equally well for men and women, to get and stay lean and lose fat and build / maintain muscle - it does not always take supplements, you see (learn more)?

  Sillicium: While you probably never thought about it, sillicium (organic) is present in celery, peppers, carrots, potatoes, unrefined grains and cereals and beets, all sorts of veggies and fruits, basically everything that growth on earth that has silica in it. The maximum daily recommended dose is 10.5 mg Si/day; and being a structural element of the connective tissue, it is actually not surprising that studies (mostly in vitro or rodent, unfortunately) have demonstrated that silanols (groups of hydrogen and sillicium compounds, similar to the hydrocarbides) provoke the formation of bridges between the hydroxylated amino acids of the elastic fibres and collagen fibres protecting them from non-enzymatic glycolysation and decreasing their degradation rate.
  
  Sillicum also acts as a coenzyme during interstitial matrix macromolecule synthesis. As such it helps reorganize structural glycoproteins and proteoglycans by stimulating polar amino acid grouping and normalizing hydrophilic capacity. Both effects which would obviously be highly desirable for someone suffering from a compromised dermal glycoprotein matrix. 
  
  In view of the fact that it has also been reported to increase microcirculation by modifying venous capillary and lymphatic permeability and has even been shown to stimulates cAMP synthesis as well as triglyceride hydrolysis and thus promote the release of fatty acids from the stored fat cells, it appears to be the perfect nutrient for any woman suffering from cellulite... in view of this fact it is surprising that I could not find a single reputable study proving its effects (note: I did not find one showing the opposite either) 

Actually, the next and last item on the list would be retinol,  but instead of just adding it to the bottom I want to briefly recapitulate that it was a 12-week treatment with weekly applications of intense pulsed light (the equipment used was a Quadra Q4 IPL) with a wavelength of 585-nm and nightly applications of a compounded retinyl-based cream (330 U/cc) that was applied after the ladies had used some aceton to remove the protecive layer of the skin 5x / week (Fink. 2006).

Some more details on the retinol / retinyl palmitat studies

In that it is interesting to note that the scientists picked retinyl palmitate not just for its better safety profile (compared to all-trans-retinoic acid) but also due to its short half-life, its well-known ability to stimulate type I collagen, and its ability to resist air oxidation.

Figure 6: Increase in blood flow in 20 women with moderate cellulite of the thighs treated twice daily on one side for 6 months with a 0.3% stabilized retinol cream while the opposite side was treated with the vehicle (Kligman. 1999)

In a previous study by Kligman et al. (1999) a similar cream containing 0.3% stabilized retinol did lead to marked increases in the blood flow as well as the synthesis of glycosaminoglycans and collagen in a group of 20 women with moderate cellulite on the thighs. Moreover, ...

"[t]here was also a marked reduction in the density of hypoechogenic areas on the retinol sides, from 53% to 18% of black pixels on image analysis. Blood flow measurements were unchanged on the vehicle sides but increased significantly on the retinol sides. Thickness measurements by ultrasound scan were unchanged on the vehicle sides but increased significantly on the retinol sides, from 1.44 to 1.60 mm." (Kligman. 1999)

In their study, Fink et al. observed responses in both the patients who received the combination treatment with the pulsed laser and retinol, as well as in those who received only the laser therapy; and with 60% (9) of their patients having a ≥ 50% improvement in cellulite at 3 months that lasted for 7 of the women up to the 8-months follow up, the overall results are pretty impressive.

Visible not just measurable improvements most likely due to vitamin A

Before and after pictures of the second, 50 year old patient in the vitamin A + pulsed laser study (Fink. 2006)

As I already mentioned on the show, though, the actual reason I picked this study to anchor the show were the two before and after pictures. The first set of which (see top of the page) is the one I already published on the SuppVersity Facebook Wall as a sneak preview, the other one that was taken from a 50 year-old patient (see image to the right) shows similar improvements. Due to the fact that she started out with a higher grade of cellulite, the end-result is yet not as astonishing as the one of the 37 year-old women you "know" already. Both women were in the combined treatment group and in all honesty, I personally consider the retinol the more promising therapeutic agent of the two.

As I told Carl on the show it cannot be excluded that the combination of tissue breakdown from the laser and the "collagen-anabolic" effects of retinol are perfect synergists. Similarly, it is difficult to say, whether the use of aceton only rendered the 2x/day application that was used in the Kligman study unnecessary or whether it was the removal of the stratum corneum that made the treatment so effective.

---

Bottom line: I would hope to see ongoing research in particular with regards to topical based retinol treatments for cellulite. And if respective results are published outside of the bazillion of small scale "studies" that come with the endless (and endlessly hilarious) amount of patents for all sorts of snake oil, I can guarantee that they will be part of the regular SuppVersity news (NO, I am not going to write another special, I am exhausted any you can keep all typos and worse mistakes for yourself ;-)


References:

• Di Salvo RM. Controlling the appearance of cellulite: surveying the cellulite reduction effectiveness of xanthines, silanes, CoA, 1-carnitine and herbal extracts. Cosm Toil 1995; 110: 50–59.
• Fink JS, Mermelstein H, Thomas A, Trow R. Use of intense pulsed light and a retinyl-based cream as a potential treatment for cellulite: a pilot study. J Cosmet Dermatol. 2006 Sep;5(3):254-62.
• Hachem A, Borgoin JY. Étude anatomo – clinique des effets de l’extrait titré de centella asiatica dans la lipodystrophie localisée. La Méd Prat 1979; 12(4): 17–21.
• Hausen BM. Centella asiatica (indian pennywort), an effective therapeutic but a weak Sensitizer. Contact Dermatitis. 1993; 29(4): 175–179. 
• Kligman AM, Pagnoni A, Stoudemayer T. Topical retinol improves cellulite. Journal of Dermatological Treatment. 1999; 10: 119–25
• Lotti T, Ghersetich I, Grappone C, Dini G. Proteoglycans in so-called cellulite. Int J Dermatol. 1990 May;29(4):272-4.
• Querleux B, Cornillon C, Jolivet O, Bittoun J. Anatomy and physiology of subcutaneous adipose tissue by in vivo magnetic resonance imaging and spectroscopy: relationships with sex and presence of cellulite. Skin Res Technol. 2002 May;8(2):118-24.
• Rosenbaum M, Prieto V, Hellmer J, Boschmann M, Krueger J, Leibel RL, Ship AG. An exploratory investigation of the morphology and biochemistry of cellulite. Plast Reconstr Surg. 1998 Jun;101(7):1934-9.
• Rossi AB, Vergnanini AL. Cellulite: a review. J Eur Acad Dermatol Venereol. 2000 Jul;14(4):251-62.
• Russe-Wilflingseder K, Russe E, Vester JC, Haller G, Novak P, Krotz A. Placebo controlled, prospectively randomized, double-blinded study for the investigation of the effectiveness and safety of the acoustic wave therapy (AWT(®)) for cellulite treatment. J Cosmet Laser Ther. 2013 Jun;15(3):155-62.
• Turati F, Pelucchi C, Marzatico F, Ferraroni M, Decarli A, Gallus S, La Vecchia C, Galeone C. Efficacy of cosmetic products in cellulite reduction: systematic review and meta-analysis. J Eur Acad Dermatol Venereol. 2013 Jun 14.

Put the "A" to the "D": Very High Dietary Vitamin A (Retinol, not Beta Carotene!) Content Ameliorates Visceral Adiposity and Improves Insulin Sensitivity in Obesity Prone Rats

What's the first letter in the alphabet? "D"? Well if you look at current research on vitamins, you would think so. Vitamin D is everywhere, vitamin A - if anything - its toxic antagonist. You, as a faithful student of the SuppVersity know better anyway: balance is where the magic lies; and thus you probably won't be surprised that not vitamin D, but vitamin A supplementation improves insulin sensitivity and ameliorates weight gain in a group of obesity prone rats on their favorite fattening stock-diet (Jeyakumar. 2011).

Image 1: Molecular structure of all-trans retinol

In the Journal of Diabetes, Obesity and Metabolism, Jeyakumar et al. published the results of an early 3-months intervention with a vitamin A-enriched diet (129mg vitamin A/kg diet) on visceral obesity and insulin sensitivity in 50days old obesity prone (WNIN/ob strain) rats:

Compared to stock diet-fed obese rats, vitamin A-enriched diet fed-obese rats had reduced body weight gain, visceral adiposity and improved insulin sensitivity as evidenced by decreased fasting plasma insulin and unaltered glucose levels.

Image 2: WNIN obese (A) and normal rat (B)
aged 12 months (image from Reddy. 2009)

The scientists explain their observations by another observation they made. Compared to rats fed the standard stock-diet, the vitamin A group exhibited an increased phosphorylation of the insulin receptor on the soleus muscle (this was the one the scientists used to access muscular insulin sensitivity via measuring gene transcription). By decreasing protein tyrosine phosphatase1B (PTP1B), consequently increasing insulin receptor phosphorylation and thus locally increasing insulin sensitivity, vitamin A had a glucose repartitioning effect, shuttling blood sugar into the muscle instead of having it converted to triglycerides that would consecutively be stored in the form of unhealthy visceral fat depots.

Although news like this usually go unrecognized, this is by far not the first study showing beneficial effect in obesity prevention and even treatment. In a 2005 study published in the Journal of Molecular Endocrinology,  Jeyakumar et al. had already published similar findings, indicating that an increase in dietary Vitamin A intake resulted "in a significant reduction in the adiposity index and retroperitoneal white adipose tissue (RPWAT) weight in obese rats" (Jeyakumar. 2005).

Jeyakumar et al.'s results stand in line with previous largely unrecognized studies on the effects of low vitamin A levels on adipose tissue development about which Ribot et al. (Ribot. 2001) write in the research journal Obesity:

Vitamin A-deficient diet feeding led to a marked increase of adiposity and to a small increase of body weight. Hypertrophy of white adipose tissue depots correlated with enhanced PPAR-gamma-2 expression. Hypertrophy of BAT, in contrast, correlated with a decrease of PPAR-gamma-2 expression that may contribute to the known reduced thermogenic potential of BAT under conditions of vitamin A restriction. Treatment with tRA [trans retinoic acid =vitamin A] triggered a reduction of adiposity and body weight that correlated with a down-regulation of PPAR-gamma-2 expression in all adipose tissues.

And in July 2003 Felipe et al. (Felipe. 2004) submitted a paper to the American Diabetes Association describing how

RA [retinoic acid] administration to normal mice resulted in reduced resistin mRNA levels in brown and white adipose tissues, reduced circulating resistin levels, reduced body weight, and improved glucose tolerance

in mice. While there appear so be a difference in the localization of resistine expression in rodents and humans (in rodents it is mainly released by fat cells, in humans and primates primarily by immune and epithelial cells), the negative effects of high serum levels of resistin on insulin sensitivity appears to be same in both species.

After all, that seems not so bad for a "vitamin", the reputation of which is almost as bad as that of the most fundamental building block of all your hormones: cholesterol. And guess what, foods such as eggs, liver and other organ meats are high in both: Vitamin A (as retinol not beta carotene, which many people have a hard time to convert) and cholesterol! Wouldn't this be a good reason to (re-)introduce these traditional, once highly appreciated foods back into your diet? One or two eggs a day (of course including the yolk), some liver once a week and a lot of sun and outdoor activity to bolster up both your vitamin A and D levels - what more could you ask for?

Retinol (Vitamin A) - A Re-Discovered Weapon in the Battle Against Atherosclerosis: Reduced Progression in Patients, Protection For Healthy Subjects From 25,000IU/Day Retinol

No it's not fish oil that's going to save your a** from dying of heart attack. It's vitamin A! 25,000IU/day for those who are already suffering from atherosclerotic lesions and heard disease could do the trick.

600,000 people die of heart disease in the United States every year–that’s 1 in every 4 deaths; and at least some could have been prevented, if vitamin A had not been demonized as bone-dissolving kidney and liver killer for decades. That's at least what the results of a recent study from the Shahid Beheshti University of Medical Sciences in the - at least in terms of medical paradigms - open-minded Iran (Mottaghi. 2014). Unlike their Western colleagues who would probably considered the provision of 25,000IU of retinyl palmitate per day an act of personal injury, Azadeh Mottaghi and his colleagues dared administering the said amount of pre-formed vitamin A to 31 atherosclerotic patients and 15 healthy controls for 4 full months; and the results were... Impressive!

One way to maximize your activity is HIIT - learn more at the SuppVersity

Inactivity = global killer!

High Fat & the Heart?

Chocolate not heart healthy

Pre-hypertension not benign!

N3 for heart, N6 for brain

Choline for everyone!

In the atherosclerotic patients, the provision of extra vitamin A supplementation resulted in significant decrease in IL-17 gene expression (-47%) in fresh cell, 18% in PHA activated cells and 35% in ox-LDL activated cells (p<0.05 for all).

RORc gene expression (indicative of the progression of atherosclerosis) in fresh cells as well as ox-LDL activated cells decreased significantly after vitamin A supplementation in atherosclerotic patients (p=0.0001 for both).

Figure 1: IL-17 & RORc levels in LDL- and PHA activated cells relative to baseline (Mottaghi. 2014)

No wonder, I mean, most people tend to be so high on vitamin D (figuratively) that they totally forget about Vitamin A and its crucial roles in mediating immune responses (Winoto. 2002). Retinoic acid and its metabolits and analogues are capable of ameliorating various models of autoimmune diseases such as rheumatoid arthritis (Miyagawa. 2002), type 1 diabetes (Zunino. 2007) and ulceratative colitis (Bai. 2009). A strong suppressive effect of retinoids on pro inflammatory Th17 cells function via down regulation of RORc, as it was observed in the study at hand, has been demonstrated in vitro, before. Retinoids have  can also suppress Th17 function via interactions with the retinoid alpha receptor right on the cell surface.

In vivo, it has been demonstrated that retinoic acid (RA) enhances TGF-β and Foxp3 expression and will thus decrease the differentiation of the rampant Th17 cells and downregulate their IL-17 production (Mucida. 2007) The exact underlying mechanism is not that important in this context, what is important though, is the fact that it worked in fresh cells (see above) and in phytohemagglutinin (PHA) activated cells, i.e. immune cells on a rampage that have been activated by the bean-lectin phytohemagglutinin (the reason you should never eat raw beans).

Apropos rampage, it's worth noticing that the provision of extra vitamin A led to a significant reduction in RORc gene activity and thus atherosclerotic potential in both, the already active, and activated Th-17 cells of the atherosclerotic subjects, and the PHA- and LDL-activated Th-17 cells of the healthy subjects - in conjunction with the increase in RORc in the placebo group (see Figure 1), this observation provides convincing evidence that vitamin A can also protect healthy individuals from developing atherosclerosis.

Vitamin A, D, E & K - They are "the fat-solubles"! But how much fat do you need to absorb them?".| learn

Bottom line: It's unrealistic to assume that the provision of extra vitamin A alone would be enough to send the atherosclerosic lesions into remission. It is, however, very realistic to assume, just as the authors do it, that "vitamin A supplementation may be an effective approach to slow progression of atherosclerosis" - a marginal effect, maybe, but a significant effect for every 4th man and woman in the US who would otherwise die in 2014 due to cardiovascular disease and may now live to see another new year's fireworks. Not too bad for a "dangerous" fat soluble vitamin that cannot be patented, right?

References:

• Bai, Aiping, et al. "All-trans retinoic acid down-regulates inflammatory responses by shifting the Treg/Th17 profile in human ulcerative and murine colitis." Journal of leukocyte biology 86.4 (2009): 959-969.
• Miyagawa, Naoki, et al. "Effect of synthetic retinoid, TAC-101, on experimental autoimmune disease." Pharmacology 67.1 (2002): 21-31.
• Mottaghi, Azadeh, et al. "Vitamin A supplementation reduces IL‐17 and RORc gene expression in atherosclerotic patients." Scandinavian Journal of Immunology (2014).
• Winoto, Astar, and Dan R. Littman. "Nuclear hormone receptors in T lymphocytes." Cell 109.2 (2002): S57-S66.
• Zunino, Susan J., David H. Storms, and Charles B. Stephensen. "Diets rich in polyphenols and vitamin A inhibit the development of type I autoimmune diabetes in nonobese diabetic mice." The Journal of nutrition 137.5 (2007): 1216-1221.