|I did miss my own 1000-posts jubilee!|
Apropos regularly, it's Saturday and thus about time for a couple of "On Short Notice" items. So let's not waste any time flattering and get to the science news business:
Vitamin A essential for liver regeneration. Plus: β-carotene and cancer even in non-smokers
|So much for the vitamin A vs. D antagonism - in fact, one can't go without the other: Vitamin A & D synergize against liver cancer and increase survival rates by more then 75% (read more)|
Missing half your liver? Not a problem if you got enough "liver building" vitamin A ;-)
In a mouse model which has been genetically modified so that the rodents weren't able to store adequate levels of retinoids (yeah, there is a whole family of "vitamins A") in the liver, showed a delayed and incomplete regenerative response to partial hepatectomy (cutting away parts of the liver; PHE). As the scientists point out,
"[t]he requirement for proper retinoic acid signaling to allow for normal liver regeneration is underscored by studies of hepatocyte-specific RXRα-null mice [mice lacking the retinoid receptor]. When RXRα is ablated there is reduced hepatocyte lifespan, which is accompanied by premature hepatocyte death and the appearance of necrotic areas. RXRα ablation also results in delayed hepatocyte proliferation following PHE." (Blaner 2013)At first sight this observation goes again the often cited liver-toxicity of vitamin A. In view of nature's favorite dose-response curve, which is bell-shaped and indicates that bad things (often similar or even identical ones) happen in both deficiency and toxicity states, it's only logical, though. Plus, similar effects have been observed for wound-healing decades ago (Gerber. 1982) and Ehrlich and Hunt report in a 1968 paper in the Annals of Surgery that the administration of vitamin A blunts the negative effects on cortisol on wound healing and appears to be necessary for optimal tissue regeneration (Ehrlich. 1968).
So, another good reason to pop vitamin A supplements?
|Supplementation with very high doses of isolated beta-carotene could in fact induce a state of "vitamin A resistance" in response to the formation of a metabolite that blocks the RXR receptor just like a SERM like clomiphene citrate block the estrogen receptor (read more).|
Polydextrose has non-noticeable, but significant satiety effects(Astbury. 2013) -- I know the headline sounds confusing, but basically that's the long and short of the results, Astbury, Taylor and MacDonald present in their most recent isse in the British Journal of Nutrition. The scientists fed 12 male and 9 female healthy university students (mean age 23.2y; BMI 22.3kg/m²) who had consumed identical breakfasts at 8:00am with isocaloric (210kcal) "preload" mid-morning snacks at 10:45am and 90min before they had a pasta-based test meal, of which they were supposed to eat as much as it would take to feel comfortably full.
|Figure 1: Food intake (in kcal) after mid-morning snack with different amounts of polydextrose (left); caloric intake on the subsequent meals of the day (right; Astbury. 2013)|
50% energy availability, a source of SCFA, tasty & easy to process - perfect diet 'food'?
|With only 50% energy availability and 50% being fermented to short chain fatty acids (SFCA), the 89% dextrose, 10% sorbitol & 1% percent citric acid molecule, polydextrose could actually be a better choice for dieters than WMHDP (learn more about the SCFA based fat burning effects of resistant starches and how to make fat burning pancakes)|
If that worked with every meal and you could achieve a ~20% reduction in energy intake, this alone should help you shed some weight pretty effortlessly. And as if that was not enough, already the polydextrose drinks was even more palatable than the sugary original; with the highest polydextrose content being perceived as most "creamy" - bon appetit ;-)
Even shorter news - "On real short notice", so to say ;-)I am well aware that what began as short news has as of late turned into a bunch of regular news - well, almost. So I decided to try and cut the last two items in today's installment short, in order to have them fit into what you would actually expect from a "on short notice" ;-)
- Exercise nullifies bad effects of high fructose diet (Moraes-Silva. 2013) -- A paper by scientists from the University of Sao Paulo
puts the "lack of exercise / insuficient activity" hypothesis of
obesity back on the radar. Even with an otherwise highly detrimental liquid
fructose overload of 100g/l in their drinking water, the rodents in the
study Moraes-Silva et al. conducted, did have normal (within
statistical limits) glucose tolerance, blood pressure and heart disease
risk as the rodents in the sedentary and the exercised control groups.
Figure 2: Regular exercise maintains insulin sensitivity, cardiovascular disease risk and blood pressure even in the presence of pathologically high liquid fructose ingestion (Moraes-Silva. 2013)
Diabetes and female sexual dysfunction correlate (Pontiroli. 2013) -- We already know that diabetes is a, if not the #1 risk factor for male sexual dysfunction, these days. Now a recent meta-analysis that's going to be published in one of the future issues of The Journal of Sexual Medicine found a 150% increase in sexual dysfunction in type II diabetes. Whether or not this was related to the higher depression rates in diabetic women cannot be said. What is certain, though, is that the BMI was a positive predictor of the effect size. In other words, the negative impact on sexual function increased with the degree of adiposity.
Additional read for those women who feel it's their husband's performance that's to blame for their anorgasmia: "Pedalium murex Linn. fruits more effective than sildenafil in the long run and increases testosterone by 125%" (read more)
The obligatory reminder: In the mean time I'd suggest you devour the latest SuppVersity Facebook News @ www.facebook.com/SuppVersity. As usual they will receive a couple of updates way before the next official SuppVersity post is going to see the light of the day. Let's see, some of the most recent news are even remotely related to the On Short Notice items of today:
- Penis pumps - Scientists believe they are going to make a revival as a means of penile rehabilitation after surgery for prostate cancer (read more)
- Stress renders cancer immortal - What has just been observed in a rodent model of prostate cancer could have important implications for other cancers, as well (read more)
- PDE5 inhibitor for him, PDE-4 inhibitor for her? Study suggests: PDE-4 inhibitors could improve female sexual function (read more)
- Goose liver for the liver - When it's high in selenium goose liver could protect your liver from the assault of excessive alcohol consumption (read more)
- Astbury NM, Taylor MA, Macdonald IA. Polydextrose results in a dose-dependent reduction in ad libitum energy intake at a subsequent test meal. Br J Nutr. 2013 Jan 23:1-9.
- Druesne-Pecollo N, Latino-Martel P, Norat T, Barrandon E, Bertrais S, Galan P, Hercberg S. Beta-carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials. Int J Cancer. 2010 Jul 1;127(1):172-84.
- Ehrlich HP, Hunt TK. Effects of cortisone and vitamin A on wound healing. Ann Surg. 1968 Mar;167(3):324-8.
- Gerber LE, Erdman JW Jr. Effect of dietary retinyl acetate, beta-carotene and retinoic acid on wound healing in rats. J Nutr. 1982 Aug;112(8):1555-64.
- Moraes-Silva IC, Mostarda CT, Moreira ED, Silva KA, Dos Santos F, De Angelis K, Farah VD, Irigoyen MC. Preventive role of exercise training in autonomic, hemodynamic and metabolic parameters in rats under high risk of metabolic syndrome development. J Appl Physiol. 2013 Jan 17.
- Pontiroli AE, Cortelazzi D, and Morabito A. Female Sexual Dysfunction and Diabetes: A Systematic Review and Meta-Analysis. J Sex Med. 2013 [e-pub ahead of print]