Alguns Suplementos Podem Aumentar O Risco De Desenvolver Câncer De Próstata

[PBV 64]

Um estudo publicado na British Journal of Cancer está relacionado alguns suplementos utilizados por fisiculturistas ao câncer de próstata. O autor do estudo, o Dr. Tongzhang Zheng, concluiu que o risco é ainda maior para os homens que começaram a usar os suplementos antes dos 25 anos ou que os usaram frequentemente por vários anos.

Segundo Zheng, a relação observada entre os suplementos e os casos de câncer foi forte. Para chegar aos resultados, o pesquisador entrevistou 900 homens das cidades estadunidenses de Massachusetts e Connecticut e avaliou centenas de critérios. 356 participantes haviam sido diagnosticados com o câncer e 513 não.

Os dados mostram que os homens que usaram suplementos constantemente têm 65% mais risco de desenvolver o tumor na próstata quando comparados com os que nunca os ingeriram. O número salta para 165% quando mais de um tipo de suplemento foi utilizado. Pessoas que começaram a ingerir os estimulantes antes dos 25 anos também estão entre as mais afetadas pela doença.

Os suplementos apontados no estudo são os baseados em creatina e androstenediona. Outros tipos de produtos não foram citados na publicação científica e outras pesquisas mais específicas devem ser realizadas para tentar isolar os componentes que aumentam o risco de câncer.

Fonte:http://www.megacurioso.com.br/saude-e-beleza/69891-alguns-suplementos-podem-aumentar-o-risco-de-desenvolver-cancer-de-prostata.htm

http://www.nature.com/bjc/journal/v112/n7/full/bjc201526a.html

EDIT:

https://news.brown.edu/articles/2015/04/muscles

http://suppversity.blogspot.com.br/2015/04/will-muscle-building-supplements-give.html

Editado Abril 15, 2015 às 13:52 por PBV

[Torf 11505]

Muito vago... Só mesmo lendo o artigo completo para ver mesmo.

[C.Golden 1622]

É preocupante, mas com tantos alimentos ruins hoje em dia, o risco de câncer vem de todos os lados. Infelizmente.

[PBV 64]

Muito vago... Só mesmo lendo o artigo completo para ver mesmo.

É por isso que tem as fontes '-'

[Visitante usuario_excluido2333]

Realmente muito vago, nem menciona nada, além de o fator de impacto desta revista nem ser muito alto se não estou enganado...

Edit: Foi mencionada a creatina mesmo.

Editado Abril 15, 2015 às 13:46 por fitnessboy123

[PBV 64]

Desculpem, não entendi o que querem dizer com "muito vago", apesar de não achar que esse "estudo" tenha credenciais para tal afirmação, porém, não é vago. É a penas a título de informação

PROVIDENCE, R.I. [brown University] — Men who reported taking muscle-building supplements, such as pills and powders with creatine or androstenedione, reported a significantly higher likelihood of having developed testicular cancer than men who did not use such supplements, according to a new study in the British Journal of Cancer.

Moreover, said study senior author Tongzhang Zheng, the associated testicular germ cell cancer risk was especially high among men who started using supplements before age 25, those who used multiple supplements and those who used them for years.

“The observed relationship was strong,” said Zheng, who led the study at Yale University before joining the Brown University School of Public Health as a professor of epidemiology. “If you used at earlier age, you had a higher risk. If you used them longer, you had a higher risk. If you used multiple types, you had a higher risk.”

Testicular cancer incidence rose to 5.9 cases per 100,000 men in 2011, from 3.7 cases in 100,000 in 1975, Zheng said. Researchers aren’t sure why.

“Testicular cancer is a very mysterious cancer,” he said. “None of the factors we’ve suspected can explain the increase.”

The study is the first analytical epidemiological study of the possible link between supplements and testicular cancer, the authors wrote in the journal. The work was inspired by mounting evidence that at least some supplement ingredients may damage the testes.

“Our study found that supplement use was related to a higher risk of developing testicular cancer. These results are important because there are few identified modifiable risk factors for testicular cancer,” said Russ Hauser, professor of environmental health science at Harvard T.H. Chan School of Public Health and a main collaborator of the research.

Testing the odds

To conduct the study, Zheng’s research team conducted detailed interviews of nearly 900 men from Massachusetts and Connecticut — 356 of whom had been diagnosed with testicular germ cell cancer, and 513 who had not. In the interviews, researchers asked the men not only about their supplement use but also about a wide variety of other possible factors such as smoking, drinking, exercise habits, family history of testicular cancer, and prior injury to their testes or groin.

After tallying their data and accounting for all those possible confounders, as well as age, race, and other demographics, the researchers found that the men who used supplements had a 1.65 odds ratio (a 65-percent greater risk) of having developed testicular cancer compared to the men who did not use supplements.

The researchers defined “use” as consuming one or more supplements at least once a week for four consecutive weeks or more.

The odds ratios increased to 2.77 (a 177-percent greater risk) among men who used more than one kind of supplement, and to 2.56 among men who used supplements three years or longer. Men who started using supplements at age 25 or younger also had an elevated associated odds ratio of 2.21, the researchers calculated.

“Considering the magnitude of the association and the observed dose-response trends, muscle-building supplements use may be an important and modifiable exposure that could have important scientific and clinical importance for preventing testicular germ cell cancer development if this association is confirmed by future studies,” the authors conclude in the study.

Future large epidemiologic studies and lab experiments would be necessary to establish a causal link between supplements and testicular cancer.

The study’s lead author is Ni Li of Yale University and the Chinese Academy of Medical Sciences. Other authors are Pat Morey of Harvard T.H. Chan School of Public Health; Theodore R. Holford, Yong Zhu, Yawei Zhang, Bryan A. Bassig, Stan Honig, and Helen Sayward of Yale; Chu Chen and Stephen Schwarz of the Fred Hutchinson Cancer Research Center; Peter Boyle of the International Prevention and Research Institute in Lyon, France; Zhibin Hu and Hongbin Shen of Nanjing Medical University; and Pable Gomery of Massachusetts General Hospital.

The U.S. National Institutes of Health, the National Natural Science Foundation of China, The Beijing Natural Science Foundation, and the Beijing Nova Program supported the research.

Ou então

http://suppversity.blogspot.com.br/2015/04/will-muscle-building-supplements-give.html

hat being said, reason #1 to take the results of the study with the necessary skepticism is a combination of false recall and flat-out lies / not disclosing one's complete "supplement" regimen. Moreover, the fact that the subjects were asked about a finite set of 30 different types of MBS powders or pills which certainly didn't include powerful designer steroids made it even easier for the study subjects to conceal some o the "supplements" (haha) they actually took. Against that background it's a bold claim to say that

That's even more true in view of the fact that lies and recall errors are one thing that hampers the reliability of the results, while a statistically significant difference in the rate of (again) reported injuries to the groin which has long been shown to increase the risk of testicular cancer (Coldman. 1982; Oliver. 1994) is another one and reason #2 to take the results of this study with appropriate skepticism.

No, creatine does not give you cancer due to elevated DHT. As you know from a previous SuppVersity article, the increase in DHT that was observed in only one study may be statistically significant, but physiologically irrelevant (learn more).

The fact that the 95% confidence levels (95% CI: 1.11–2.46 total cancer risk, 95% CI: 1.34–3.63 cancer before 25, 95% CI: 1.39–4.74 long-term use) adds another question mark to the claim that using creatine once or regularly is going to give you germ cell cancer.
Figure 2: While both undescended testes and injuries to testes and groin can increase the risk of testicular cancer, only the latter shows a statistical significant inter-group difference between cases and controls (Li. 2015). In conjunction with reason #3 which is the fact that there is absolutely no mechanism that would explain pro-carcinogenic effects of non-steroidal supplements in general and creatine and protein supplementation in particular (creatine has even been shown to inhibit breast cancer and general tumor growth | Miller. 1993; Juhn. 1998 and anti-tumor effects mostly in the colon, though, of whey protein have been reported among others by Eason, 2004; Xiao, 2005 & 2006; Parodi, 2007; Attaallah, 2012; etc.), you may even call it "bad science" or "sensationalism" that that none of the several "reviews" of this study on the Internet mention the most important of all findings, which is the non-significance of the results of the TGCC subtype analysis and reason #4:

"Analyses by TGCC subtype suggested similar associations between use of MBS and the risk of seminoma and nonseminoma (all the P-values for hierarchical coefficients tests were >0.05)."

Against that background I would be curious how the scientists were able to do an exploratory stratified analysis which found that "both creatine and proteins increased the risk of TGCC significantly (OR =2.55, 95% CI: 1.05–6.15)" (Li. 2015).
Table 1: Association Between MBS Use and the Risk of TGCC, Connecticut and Massachusetts, 2006–2010 (Li. 2015). That sounds very odd considering the facts that (a) no associations were found for a complete analysis, that ( there's no mention what exactly the data was stratified for and that © no previous epidemiological study provides the slightest hint that there may be a potentially causal association between supplement use and testicular cancer.

Speaking of causality, you are aware that the "odds ratios" from the case-control study like the one at hand provide extremely weak evidence? Evidence that cannot provide any information about cause and effect? If that's not your first visit to the SuppVersity you probably knew that already. If it's not, I believe it may be worth remembering that correlation and causation are two different pairs of shoes; or, like my friend Carl Lanore likes to explain it: Just because there are firefighters all over the place, whenever a house burns down (association), they're not the cause of the fire (causation).

Learn more about the old-wife's tale about creatine, DHT and hair loss. Overall, it's probably rather the Yale and Harvard labels than the quality of the data that made this study pop up all over the Internet. With less than 1000 subjects, a possible reporting bias, error of recall, an interview that used a pre-compiled list of agents instead of just asking which product the subjects used and reconciling the data afterwards and the hushed up non-significance of the results of the full agent-specific analysis should be four good reasons not to freak out about possible increase of testicular cancer risk from 0.2% in the general population (Schottenfeld. 1980) to 0.6% which would be the corresponding 155% risk increase Li et al. report for creatine or protein supplements.

If anything, there may be a generally increased risk of prostate cancer due to high(er) protein intakes and correspondingly increased IGF-1 levels as it was observed among others by the scientists who conducted the European Prospective Investigation into Cancer (cf. Key. 2014). If you re-read my previous posts on dairy and cancer risk (article I, article II, article III, article IV), though, you will notice that even this association is a weak one that was observed in some, but by no means all studies on dairy intake and cancer risk. Corresponding evidence for creatine is - in spite of the existence of tons of long-term safety studies for what probably is the best researched ergogenic on the market, simply non-existent | Comment on Facebook!

References:

• Attaallah, Wafi, et al. "Whey protein versus whey protein hydrolyzate for the protection of azoxymethane and dextran sodium sulfate induced colonic tumors in rats." Pathology & Oncology Research 18.4 (2012): 817-822.
• Coldman, A. J., J. M. Elwood, and R. P. Gallagher. "Sports activities and risk of testicular cancer." British journal of cancer 46.5 (1982): 749.
• Eason, Renea R., et al. "Dietary exposure to whey proteins alters rat mammary gland proliferation, apoptosis, and gene expression during postnatal development." The Journal of nutrition 134.12 (2004): 3370-3377.
• Li, N., et al. "Muscle-building supplement use and increased risk of testicular germ cell cancer in men from Connecticut and Massachusetts." British journal of cancer 112.7 (2015): 1247-1250.
• Juhn, Mark S., and Mark Tarnopolsky. "Potential side effects of oral creatine supplementation: a critical review." Clinical Journal of Sport Medicine 8.4 (1998): 298-304.
• Key, Timothy J. "Nutrition, Hormones and Prostate Cancer Risk: Results from the European Prospective Investigation into Cancer and Nutrition." Prostate Cancer Prevention. Springer Berlin Heidelberg, 2014. 39-46.
• Miller, Elizabeth E., Audrey E. Evans, and Mildred Cohn. "Inhibition of rate of tumor growth by creatine and cyclocreatine." Proceedings of the National Academy of Sciences 90.8 (1993): 3304-3308.
• Oliver, M. C. "Social, behaviouraland medical factors in the aetiology of testicular cancer: results from the UK study." Br. J. Cancer 70 (1994): 513-520.
• Parodi, Peter W. "A role for milk proteins in cancer prevention." Australian journal of dairy technology 53.1 (1998): 37-47.
• Schottenfeld, Davit, et al. "The epidemiology of testicular cancer in young adults." American Journal of Epidemiology 112.2 (1980): 232-246.
• Xiao, Rijin, Thomas M. Badger, and Frank A. Simmen. "Dietary exposure to soy or whey proteins alters colonic global gene expression profiles during rat colon tumorigenesis." Molecular Cancer 4.1 (2005): 1.
• Xiao, Rijin, et al. "Dietary whey protein lowers serum C-peptide concentration and duodenal SREBP-1c mRNA abundance, and reduces occurrence of duodenal tumors and colon aberrant crypt foci in azoxymethane-treated male rats." The Journal of nutritional biochemistry 17.9 (2006): 626-634.

[Torf 11505]

É por isso que tem as fontes '-'

Mas o artigo completo é PAGO... Ou näo? Você tem disponibilizado?

Pelo que deu a entender, pelo resumo do resumo, a metodologia se baseou apenas em entrevistas. Gostaria de saber que tipo de perguntas foram feitas. Se foi feita sondagem também acerca da alimentacäo, outros hábitos, etc.

[PBV 64]

Mas o artigo completo é PAGO... Ou näo? Você tem disponibilizado?

Pelo que deu a entender, pelo resumo do resumo, a metodologia se baseou apenas em entrevistas. Gostaria de saber que tipo de perguntas foram feitas. Se foi feita sondagem também acerca da alimentacäo, outros hábitos, etc.

Veja se te ajuda, o mesmo artigo, em outros links:

Não li:

http://www.upi.com/Health_News/2015/04/13/Muscle-building-supplements-linked-to-testicular-cancer/7361428937517/

http://www.medicaldaily.com/using-bodybuilding-supplements-may-increase-risk-testicular-cancer-329294

Li:

http://www.washingtonpost.com/news/to-your-health/wp/2015/04/13/study-finds-troubling-link-between-use-of-muscle-building-supplements-and-cancer/

http://suppversity.blogspot.com.br/2015/04/will-muscle-building-supplements-give.html

https://news.brown.edu/articles/2015/04/muscles

Editado Abril 15, 2015 às 14:01 por PBV

[Sh'lac 9]

Não sei se o estudo é vago pois ainda não o li todo. Mas a sua chamada é meio tendenciosa. Ainda que você diga "alguns suplementos" no título, no corpo do texto dá a entender como se fossem todos. Porque em vários trechos o leitor não é lembrado de que são alguns, e há um trecho que diz algo como "quem usa mais de um tipo de suplemento tem o risco potencializado", o que obviamente leva quem lê rápido a uma análise equivocada.

Vou ler os artigos em si. Mas acho melhor você especificar quais suplementos logo no seu texto. Existem muitos novatos e desatentos no fórum. A maioria das pessoas toma proteínas ou hipercalóricos, que são para substituir parte da alimentação, e não suplementos para melhorar a performance como creatina, estimulantes e afins, que aparentemente são os tratados nos estudos.

Além disso, seria bom não postar solto assim. Contextualizar com a importância da publicação é válido, por exemplo.

Editado Abril 15, 2015 às 14:25 por Sh'lac

[Torf 11505]

Perae, deixa só eu entender uma coisa a respeito da metodologia.

O uso de suplementos foi isolado na pesquisa?

Pergunto isso porque as pessoas mentem.

Ainda mais no nosso meio, que é um antro de gente mentirosa e hipócrita.

O que mais tem é nego se entupindo de hormônios e dizendo que ficou grande porque toma whey + malto no pós treino.

Aí o cara participa de uma pesquisa que pretende relacionar câncer com uso de suplementos e esconde que usa ou já usou esteroides.

Aí fica difícil estabelecer uma relação de causa e efeito.

Exatamente. =)

Por isso que eu falei que é de extrema relevância conhecer o questionário por completo e que o estudo, do modo que foi apresentado pelo autor do tópico, foi muito vago.