Cromo...

[Eagle]

ancora

Med Sci Sports Exerc. 1998 Dec;30(12):1730-7. Links

Chromium picolinate effects on body composition and muscular performance in wrestlers.

Walker LS, Bemben MG, Bemben DA, Knehans AW.
Department of Health & Sport Sciences, University of Oklahoma, Norman, USA.
PURPOSE: The purpose of this study was to assess the effects of 14 wk of chromium picolinate supplementation during the final 16 wk of a preseason resistance and conditioning program on body composition and neuromuscular performance in NCAA Division I wrestlers. During this phase of training, wrestlers are primarily interested in trying to improve physical performance and wrestling technique and are not engaged in severe, acute weight loss practices commonly employed before competition. METHODS: This double-blinded, randomized placebo-controlled study involved 20 wrestlers from the University of Oklahoma assigned to either a treatment group (Cr+3; N = 7; 20.4 yr +/- 0.1) receiving 200 micrograms chromium picolinate daily, a placebo group (P; N = 7; 19.9 yr +/- 0.2), or a control group (C; N = 6; 20.2 yr +/- 0.1) using a stratified random sampling technique based on weight classification. Body composition, neuromuscular performance, metabolic performance, and serum insulin and glucose were measured before and immediately following the supplementation and training period. RESULTS: Repeated measures ANOVA indicated no significant changes in body composition for any of the groups. Aerobic power increased significantly (P < 0.002) in all groups, independent of supplementation. There were significant trial and group x trial interactions for upper body endurance (P = 0.038) and relative bench press power (P = 0.050). Post-hoc analyses revealed that the C group increased upper body endurance (P = 0.006), but none of the pre- to post-test changes in bench press power were significant. CONCLUSIONS: These results suggest that chromium picolinate supplementation coupled with a typical preseason training program does not enhance body composition or performance variables beyond improvements seen with training alone.

[Eagle]

Sports Med. 2003;33(3):213-30. Links

The potential value and toxicity of chromium picolinate as a nutritional supplement, weight loss agent and muscle development agent.

Vincent JB.
Department of Chemistry and Coalition for Biomolecular Products, The University of Alabama, Tuscaloosa, Alabama 35487-0336, USA. jvincent@bama.ua.edu
The element chromium apparently has a role in maintaining proper carbohydrate and lipid metabolism in mammals. As this role probably involves potentiation of insulin signalling, chromium dietary supplementation has been postulated to potentially have effects on body composition, including reducing fat mass and increasing lean body mass. Because the supplement is absorbed better than dietary chromium, most studies have focused on the use of chromium picolinate [Cr(pic)(3)]. Cr(pic)(3) has been amazingly popular with the general public, especially with athletes who may have exercise-induced increased urinary chromium loss; however, its effectiveness in manifesting body composition changes has been an area of intense debate in the last decade. Additionally, claims have appeared that the supplement might give rise to deleterious effects. However, over a decade of human studies with Cr(pic)(3) indicate that the supplement has not demonstrated effects on the body composition of healthy individuals, even when taken in combination with an exercise training programme. Recent cell culture and in vivo rat studies have indicated that Cr(pic)(3) probably generates oxidative damage of DNA and lipids and is mutagenic, although the significance of these results on humans taking the supplement for prolonged periods of time is unknown and should be a focus for future investigations. Given that in vitro studies suggest that other forms of chromium used as nutritional supplements, such as chromium chloride, are unlikely to be susceptible to generating this type of oxidative damage, the use of these compounds, rather than Cr(pic)(3), would appear warranted. Potential neurological effects (both beneficial and deleterious) from Cr(pic)(3) supplementation require further study.

[Eagle]

Nutr Rev. 1998 Sep;56(9):266-70. Links

Effects of chromium on body composition and weight loss.

Anderson RA.
Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA.
Chromium is an essential nutrient involved in the regulation of carbohydrate and lipid metabolism. Normal dietary intake of chromium in humans and farm animals is often suboptimal. In addition to its effects on glucose, insulin, and lipid metabolism, chromium has been reported to increase lean body mass and decrease percentage body fat, which may lead to weight loss in humans. The effects of chromium on body composition are controversial but are supported by animal studies, which increase their validity. A subject's response to chromium depends on his or her chromium status, diet consumed, type and amount of supplemental chromium, and study duration. There have been no confirmed negative effects of chromium in nutritional studies. Chromium is only a small part of the puzzle in the control of weight loss and body composition, and its effects, if present, will be small compared with those of exercise and a well-balanced diet.

[richard]

Quindi se uno studio tossicologico scopre che il cromo picolinato e' cancerogeno, ad alte dosi, oltre tutto non dicendo niente relativamente a quelle basse, uno non deve tenerne conto, perche' quello non e' uno studio che noi dobbiamo leggere?

Ho espresso il mio pensiero sul significato ed il valore da attribuire ad una ricerca scientifica (o, meglio, alla relativa pubblicazione) qui (terzo post, in particolare):

http://www.bodyweb.it/forums/showthread.php?t=156483


Perdona se non mi ripeto (anche perché, come noterai, è un discorso lunghetto ).

[Sergio]

* * *

http://www.chromiumpicolinate.org/SA...xic_damage.htm

* * *

[LEFT]One study indicated that large amounts of chromium picolinate cause chromosome damage, whereas chromium polynicotinate did not. At first, this study was widely criticized because the chromium picolinate levels were far higher than one would get with normal supplementation. Subsequently, however, many other scientific studies have called into question the safety of chromium picolinate.

Li dice che può produrre danno ai cromosomi disgregando il DNA, qui sostiene il contrario :

http://www.ncbi.nlm.nih.gov/pubmed/18261879?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

1: Toxicol In Vitro. 2008 Apr;22(3):819-26. Epub 2007 Dec 25. Links
Chromium picolinate does not produce chromosome damage.

Komorowski JR, Greenberg D, Juturu V.
Research and Development, Nutrition 21 Inc, 4 Manhattanville Road, Purchase, NY 10577, United States.
Chromium picolinate (CrPic) is used as a dietary supplement and has beneficial effects in reducing diabetes risk factors. The present study evaluated the cytogenetic effects of CrPic in bone marrow cells of Sprague-Dawley rats (5 animals/sex/group). Test animals were dosed orally with 33, 250 or 2000mg/kg of CrPic, which corresponded to doses of 4.1, 30.8 and 246mg/kg of chromium. The lowest dose of CrPic, 33mg/kg is estimated to be the human equivalent for a 50kg person (200mcg Cr). The animals were dosed once, and sacrificed either 18 or 42hours (h) later. The mitotic index was determined for each rat. Metaphase cells (50 or 100/rats) were examined for interstitial deletions, chromatid and chromosome gap, breaks or other anomalies. The average percentage of damaged cells at 18h in vehicle treated males and females were 1.2% and 0.6%, respectively. The mean values at 18h for doses of 33, 250 and 2000mg/kg, were 0.4%, 0.8%, 0.4% for males and 0.6%, 0.2% and 0.6% for females, respectively. At 42h, the mean values for vehicle treated males and females were 0.4% and 0.2%, respectively. For doses of 33, 250 and 2000mg/kg at 42h the average percent damage was 14%, 0.8% and 0.4% for males and 0.2%, 0.2% and 0.0% for females, respectively. None of these values were statistically increased compared to the vehicle controls. The positive control Cyclophosphamide (CPM) induced a significant increase in chromosomal damage at 18h averaging 30% in males and 37% in females, respectively (p<0.001). In the current study CrPic did not induce chromosomal damage in bone marrow cells at single doses of 33, 250 and 2000mg/kg of body weight and thus there was no indication of any toxicity of CrPic.
PMID: 18261879 [PubMed - in process]


Mha..... ad ogni modo il Surgeon General ed il Ministero della salute lo elimineranno immediatamente SE è così pericoloso.

[Sergio]

Ad ogni modo non voglio ridurmi qui a fare botta e risposta con link da pubmed, sappiamo benissimo che possiamo trovare studi su tutto ed il contrario di tutto, per ogni cosa che prendiamo in esame, poi visto che Eagle è medico, lascio a lui il compito di fare terr..... cioè, informazione

[richard]

Li dice che può produrre danno ai cromosomi disgregando il DNA, qui sostiene il contrario :

Sergio, puoi leggere anche tu il link che ho postato ad Eagle (terzo post)?

Perdonate se è un po' lunghetto.

[Sergio]

Sergio, puoi leggere anche tu il link che ho postato ad Eagle (terzo post)?

Perdonate se è un po' lunghetto.

Terzo post di questo thread (è mio) o terzo post tuo ?

[richard]

Terzo post di questo thread (è mio) o terzo post tuo ?

Terzo post di qui:

http://www.bodyweb.it/forums/showthread.php?t=156483






Scherzi a parte, ritengo che sia davvero il più giusto atteggiamento da tenere leggendo una pubblicazione scientifica.

[Eagle]

Ho espresso il mio pensiero sul significato ed il valore da attribuire ad una ricerca scientifica (o, meglio, alla relativa pubblicazione) qui (terzo post, in particolare):

http://www.bodyweb.it/forums/showthread.php?t=156483


Perdona se non mi ripeto (anche perché, come noterai, è un discorso lunghetto ).

Ho avuto qualche esperienza in merito a ricerche scientifiche, e non ho mai pensato (sarebbe assurdo) che il forum, me compreso, nella sezione integrazione, e quando uno parla a livello personale, abbia alcuna pretesa di rigore scientifico.

Oltre tutto in questo 3ad mi sembra di aver espersso una mia confusione, delle mie valutazioni personali, basandomi, in modo NON rigorosamente scientifico, sui dati di cui sono entrato in possesso nel giro di 10 minuti di web surfing. Quindi dati assolutamente parziali. Ma l'ho anche scritto passo per passo ...

Non voleva e non era presentata come una ricerca scientifica sulle azioni del cromo, ne tantomeno sullo stato della ricerca sulla supplementazione a base delle diverse forme di cromo.

Era un sasso gettato per vedere se la risonanza avesse prodotto qualche ritorno interessante, in termini di esperienze, positive e negative.
Magari provocatorio come atteggiamento, ma non mi sembra vietato dal regolamento ... fino ad ora almeno ...

Ne ho invece ricavato una lezione magistrale su come vanno interpretati gli studi scientifici, delle critiche di fare dell'allarmismo ingiusitificato da (mala)interpretazione fai da te della scienza vera, Sergio che se la prende perche' faccio notare alcune piccole differenze di prezzo, e nessuno che abbia scritto qualche cosa di interessante sul cromo come integratore nel bb ...

Che dire ... un successo ... ringrazio con inchino, e abbandono l'arena, chissa' che il prossimo 3ad non mi vada meglio ...

Eagle

[Sergio]

Opps... scusa, ho letto ora. Facevi riferimento al regolamento esteso, anzi, motivo in più per ritirarmi dalla discussione e suggerirei (poi fate come preferite) di postare e/o spostare questi articoli nella sezione "Scientific Corner", qui in "Integrazione" la gente a malapena legge un lungo articolo in italano, figuriamoci in ingelse.

[Eagle]

Ad ogni modo non voglio ridurmi qui a fare botta e risposta con link da pubmed, sappiamo benissimo che possiamo trovare studi su tutto ed il contrario di tutto, per ogni cosa che prendiamo in esame, poi visto che Eagle è medico, lascio a lui il compito di fare terr..... cioè, informazione

Come al solito, non capisci un caxxo (battuta, ma il senso e' quelo)

Io il cormo lo volevo provare sul serio, e non cercavo di fare terrorismo.

E non ho comunque trovato niente, su pubmed, che dica che funziona.
Quel primo studio fatto in texas nel 1998 non c'e' su pubmed (o almeno io non lo trovo).

Sui danni ho trovato molti studi che dicono che il picolinato non e' la forma migliore, ma studi che documentino danni sull'uomo ce ne sono pochi.

Ma il "PROBLEMA" di un integratore e' il bilancio tra i possibili o probabili danni e gli effetti.

Trovami uno studio su pubmed che ha visto qualche effetto nel mettere muscoli o nel perdere grasso mantenendo i muscoli.
Io non l'ho trovato, ti ripeto, ma non ho tutta la gioranta, posso fare ricerche di 10-15 minuti, poi devo chiudere.
Se lo trovi non mi fai certo un dispetto, ANZI!

Eagle

[richard]

Ragazzi, non volevo minimamente inibire la discussione.

Mi preme davvero che, postando uno studio, in generale, non si dia significato diverso/estraneo a quello che il lavoro di ricerca vuole essere. Sono in quest'ottica possiamo capire realmente perché quelle che noi consideriamo "studi contraddittori" per la Ricerca non lo siano e come mai abbiano il medesimo valore.

Il principio che deve guidare è "informarci ed informare", non "informarci e convincere."

[Sergio]

http://www.ncbi.nlm.nih.gov/pubmed/16034167?ordinalpos=5&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

Biol Trace Elem Res. 2005 Summer;105(1-3):229-48. Links
Supplementation with chromium picolinate recovers renal Cr concentration and improves carbohydrate metabolism and renal function in type 2 diabetic mice.

Mita Y, Ishihara K, Fukuchi Y, Fukuya Y, Yasumoto K.
Division of Human Life Studies, Graduate School of Life Studies, Sugiyama Jogakuen University, Nagoya, 464-8662 Japan.
To study the preventive effect of supplemented chromium picolinate (CrPic) on the development of diabetic nephropathy in mice, we analyzed the effects of CrPic supplementation on renal function and concentrations of serum glucose and tissue chromium (Cr). In experiment 1, male KK-Ay obese diabetic mice were fed either a control diet (control) or a diet supplemented with 2 mg/kg diet (Cr2) or 10 mg/kg diet (Cr10) of Cr for 12 wk. Cr10 significantly ameliorated hyperglycemia after a glucose load, creatinine clearance rates, and urinary microalbumin levels (p<0.05). In experiment 2, the Cr10 diet was fed to male KK-Ay obese diabetic mice and C57BL nondiabetic mice for 4 wk. The CrPic diet reduced urinary albumin excretion in the diabetic mice (p<0.05). Inductively coupled plasma-mass spectrometry analysis revealed that the renal Cr content and the recovery of renal Cr concentration after Cr supplementation were significantly lower in the diabetic mice than in the nondiabetic mice (p<0.01). These observations suggest that Cr supplementation of type 2 diabetic mice reduces the symptoms of hyperglycemia and improves the renal function by recovering renal Cr concentration.
PMID: 16034167 [PubMed - indexed for MEDLINE]

E ne esistono a bizzeffe di artcoli come questo...

Che poi sarebbe quello che si suol dire del cromo, che stabilizza, riduce la glicemia nel sangue, tutto li, non trasforma, ne fa "dimagrire", ne fa miracoli.

[Black87]

Comunque le ricerche su pubmed in questo campo lasciano il tempo che trovano. Se proprio si vuole si possono trovare studi anche contro il Nesquik