Carne y cáncer

[sujal]

Bueno, aprovecho para colgar algún estudio de esos científicos:

Meat Consumption and Cancer Risk
Jeanine M. Genkinger, Anita Koushik*
Published: December 11, 2007


Jeanine M. Genkinger is at the Department of Oncology, Division of Cancer Genetics and Epidemiology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, D. C., United States of America. Anita Koushik is at the Département de médecine sociale et préventive, Université de Montréal, and Axe Santé des populations, Centre de recherche du CHUM, Montreal, Quebec, Canada.

*To whom correspondence should be addressed. E-mail: anita.koushik@umontreal.ca


The large international variation in incidence rates of cancer, together with findings from migrant studies, suggest that environmental factors such as diet are associated with cancer risk. The intake of meats, such as beef, varies 3-fold across the world—consumption is highest in developed countries (23 kg/capita) compared to less developed countries (6 kg/capita) [1]. Based on Richard Doll and Richard Peto's work in 1981, it has been estimated that approximately 35% (range 10%–70%) of cancer can be attributed to diet, similar in magnitude to the contribution of smoking to cancer (30%, range 25%–40%) [2].

Meat consumption in relation to cancer risk has been reported in over a hundred epidemiological studies from many countries with diverse diets. The association between meat intake and cancer risk has been evaluated by looking both at broad groupings of total meat intake, and also at finer categorizations, particularly intakes of red meat, which includes beef, lamb, pork, and veal, and also more specifically processed meats, which includes meats preserved by salting, smoking, or curing.

Although the association of cancer and meat intake may be partially explained by high-energy or high-fat (“westernized”) diets, of greater interest is a possible direct role of potentially carcinogenic compounds that are found in meats, including N-nitroso compounds, heterocyclic amines, or polycyclic aromatic hydrocarbons. N-nitroso compounds are broad-acting potent carcinogens in animal models [3] and include nitrosamines, which require metabolic activation to be converted to a carcinogenic form, and nitrosamides, which do not require activation. Similarly, heterocyclic amines are classified as mutagens and animal carcinogens [4–8]. These compounds and others present in meats (salts, nitrates, nitrites, heme iron, saturated fat, estradiol) have been theorized to increase DNA synthesis and cell proliferation, increase insulin-like growth factors, affect hormone metabolism, promote free radical damage, and produce carcinogenic heterocyclic amines [9–16], all of which may promote the development of cancer.

Traducción:

La gran variedad registrada mundialmente en las tasas de inicidencia del cancer, junto con las mediciones de estudios sobre poblaciones que migran, sugieren que factores ambientales, como la dieta, están asociadas al cancer. La ingestión de carnes, como la carne de vaca, tiene variaciones de consumo de hasta tres veces según las regiones, siendo el consumo en los paieses desarrollados máximo (23 kg / cápita) comparado con paieses menos desarrollados (6 kg/ cápita).
Basados en los trabajos de Richard Doll y Richard Peto, de 1981, se ha estimado que aproximadamente el 35% (con un rango de 10% a 70%) de lo cánceres pueden ser atribuidos a la dieta, valores similares a la contribución del cáncer del uso de cigarrillos. (30% , rango 25% a 40%).

El consumo de carne relacionado al cáncer, ha sido recogido en mas de 100 estudios epidemiológicos efectuados en muchos paises. La asociación entre el consumo de carne y el riesgo de cáncer ha sido evaluado analizando el consumo de carnes en total, y analizando consumos particulares, como vacuno, cerdo, cordero, ternera, y también aún mas específicamente, como carnes procesadas, que incluyen sales, ahumado, y otros conservantes.

A pesar de que la relación ha sido parcialmente explicada por el elevado consumo de “energía” o dietas con altos nieveles de grasas (dieta occidentalizada), es de gran interes el potencial rol cancerígeno de compuestos presentes en la carnes, tales como los N – nitroso, aminas heterocíclicas, hidrocarburos aromáticos policíclicos. Los compuestos N- nitrosos son cancerígenos potentes de amplio espectro , al menos en animales, dentro de los cuales están las nitrosaminas, las cuales deben ser metabolizadas para convertirse en formas activas carcinogénicas y las nitrosamidas, las cuales no requieren activación. Similarmente, las aminas heterocíclicas se clasifican en mutágenos y carcerígenos sobre animales. Estos compuestos , sumados a otros también presentes en las carnes (sales, nitratos, nitritos, hierro hemo - constituyente de la hemoglobina y la mioglobina, entre otros – grasas saturadas, estradiol) se piensa que incrementan la síntesis de ADN y la proliferación celular, aumentan factores de crecimiento tipo insulina, alteran el metabolismo hormonal, promueven el daño de radicales libres, y producen aminas heterocíclicas , lo que puede promover el desarrollo de lo cánceres.

[sujal]

Red Meat Consumption during Adolescence among Premenopausal Women and Risk of Breast Cancer.
2008 Aug;17(8):2146-51. Epub 2008 Jul 31.

Linos E, Willett WC, Cho E, Colditz G, Frazier LA.
Channing Laboratory, Department of Medicine, Harvard Medical School and Brigham and Women's Hospital; Departments of Nutrition and Epidemiology, Harvard School of Public Health; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.

BACKGROUND: Adolescence may be a period of increased susceptibility to breast cancer due to regular division of undifferentiated cells that occurs between puberty and first birth. Red meat consumption during early adult life has been associated with breast cancer, but intake during adolescence has not been examined prospectively. We aimed to assess the relationship between red meat intake during adolescence and premenopausal breast cancer.

METHODS: We examined the incidence of invasive premenopausal breast cancer prospectively within the Nurses' Health Study II. A total of 39,268 premenopausal women who completed a validated 124-item food frequency questionnaire on their diet during high school, were followed for 7 years, from 1998 to 2005. Cox proportional hazards regression was used to estimate relative risks (RR) and 95% confidence intervals (95% CI).RESULTS: 455 cases of invasive premenopausal breast cancer were diagnosed between 1998 and 2005. Compared with women in the lowest quintile of red meat intake during high school, the multivariate-adjusted RR for the highest quintile of intake was 1.34 (95% CI, 0.94-1.89; Ptrend = 0.05). A significant linear association was observed with every additional 100 g of red meat consumed per day (RR, 1.20; 95% CI, 1.00-1.43; P = 0.05). This association was more pronounced in hormone receptor-positive tumors (RR, 1.36; 95% CI, 1.08-1.70; P = 0.008) and was not significant in hormone receptor-negative tumors (RR, 0.99; 95% CI, 0.61-1.61, P = 0.97).

CONCLUSION: Higher red meat intake in adolescence may increase the risk of premenopausal breast cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(8):OF1-6).

Traducción de las conclusiones: Grandes conusmos de carnes rojas en la adolescencia, es probable que aumente el riesgo de cancer de mama durante la pre menopausia.

Dietary patterns and breast cancer risk in the shanghai breast cancer study.
2007 Jul;16(7):1443-8. Epub 2007 Jul 10.

Cui X, Dai Q, Tseng M, Shu XO, Gao YT, Zheng W.
Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA.


The association of breast cancer with dietary patterns such as a western diet has not been studied in Asian women. We examined this among Shanghai Breast Cancer Study participants. Cases were of ages 25 to 64 years, diagnosed 08/1996-03/1998, and identified through a rapid case ascertainment system supplemented by the Shanghai Cancer Registry. Controls, selected from the general population of urban Shanghai, were frequency matched to cases by 5-year age group. Participants provided information on diet, lifestyle, and reproductive factors. In principal component analysis among 1,556 controls, two patterns emerged: a "vegetable-soy" pattern (tofu, cauliflower, beans, bean sprouts, green leafy vegetables) and a "meat-sweet" pattern (shrimp, chicken, beef, pork, candy, desserts). In adjusted unconditional logistic regression analyses including 1,446 cases and 1,549 controls with complete covariate data, risk was not associated with the vegetable-soy pattern. It was associated with the meat-sweet pattern (4th versus 1st quartile: odds ratio, 1.3; 95% confidence interval, 1.0-1.7; P(trend) = 0.03), but only in postmenopausal women, specifically among those with estrogen receptor-positive tumors (4th versus 1st quartile: odds ratio, 1.9; 95% confidence interval, 1.1-3.3; P(trend) = 0.03). Our findings indicate that a western diet increases breast cancer risk in postmenopausal Chinese women. They also suggest the value of quantifying aggregate risk for common combinations of foods.
PMID: 17623805 [PubMed - indexed for MEDLINE]

Conclusiones
Nuestros hallazgos indican que las dietas tipo occidental , incrementan el riesgo de cáncer de mama en mujeres chinas postmenopáusicas.

En el estudio las dietas comparadas fueron:
1. Basadas en vegetales y soja - vegetariana (tipo oriental)
2. Basadas en carnes (rojas, pollo, etc) (tipo occidental)

[sujal]

Prospective study of red and processed meat intake in relation to cancer risk.
2007 Dec;4(12):e325.

Cross AJ, Leitzmann MF, Gail MH, Hollenbeck AR, Schatzkin A, Sinha R.
Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland, United States of America. crossa@mail.nih.gov

BACKGROUND: Red meat and processed meat have been associated with carcinogenesis at several anatomic sites, but no prospective study has examined meat intake in relation to a range of malignancies. We investigated whether red or processed meat intake increases cancer risk at a variety of sites. METHODS AND FINDINGS: The National Institutes of Health (NIH)-AARP (formerly the American Association for Retired Persons) Diet and Health Study is a cohort of approximately 500,000 people aged 50-71 y at baseline (1995-1996). Meat intake was estimated from a food frequency questionnaire administered at baseline. Cox proportional hazards regression was used to estimate hazard ratios and 95% confidence intervals within quintiles of red and processed meat intake. During up to 8.2 y of follow-up, 53,396 incident cancers were ascertained. Statistically significant elevated risks (ranging from 20% to 60%) were evident for esophageal, colorectal, liver, and lung cancer, comparing individuals in the highest with those in the lowest quintile of red meat intake. Furthermore, individuals in the highest quintile of processed meat intake had a 20% elevated risk for colorectal and a 16% elevated risk for lung cancer.

CONCLUSIONS: Both red and processed meat intakes were positively associated with cancers of the colorectum and lung; furthermore, red meat intake was associated with an elevated risk for cancers of the esophagus and liver.

PMID: 18076279 [PubMed - indexed for MEDLINE]

Traducción de las conclusiones: ambas, carnes rojas procesada y no procesada estuvieron asociadas positivamente con los cánceres de colon / recto, y de pulmon. Ademas, el cosumo de carnes rojas fue asociado con un elevado riesgo de cánceres de esofago e higado.

[Fernando]

Hola Sujal,

Esta genial esta sección!. Seria interesante que a los articulos le añadieses el link de donde lo obtubiste.

Un abrazo!

Fer

[sujal]

Copiando el título en un buscador, salen algunas referencias como el Pubmed.
Estas concretamente y las del hierro las copié de un foro sobre ciencias de la salud llamado MANCIA y de donde surgió la idea de este subforo. Desde aquí, gracias a krisnesh.

[SofíaCC]

Muy buena esta información, gracias Sujal.

[sujal]

Los vegetarianos son menos propensos a contraer cáncer

Las personas vegetarianas son un 12 por ciento menos proclives que los consumidores de carne a desarrollar cáncer y esa tendencia es particularmente acentuada cuando se trata de cánceres de la sangre, informaron el miércoles investigadores británicos.

Estudios previos habían mostrado que comer mucha carne roja o procesada se relaciona con una mayor tasa de cáncer de estómago y este nuevo trabajo, en el que participaron más de 60.000 personas, confirmó un riesgo menor tanto de tumores de estómago como de vejiga entre los vegetarianos.

Pero la diferencia más sorprendente fue en los cánceres sanguíneos, como la leucemia, el mieloma múltiple y el linfoma no Hodgkin, en los cuales el riesgo de sufrir la enfermedad era un 45 por ciento más bajo entre los vegetarianos que en los consumidores de carne.

Se necesitan más estudios para sustentar estos resultados y buscar los motivos de estas diferencias, dijo Tim Key, autor del trabajo e investigador de la unidad epidemiológica de Investigación del Cáncer de la universidad de Oxford.

Key y sus colegas, que publicaron sus hallazgos en el British Journal of Cancer, realizaron un seguimiento durante más de 12 años en 61.000 consumidores de carne y personas vegetarianas, durante el cual 3.350 fueron diagnosticados con cáncer.

La investigación, que observó 20 tipos distintos de cáncer, reveló que las diferencias en el riesgo eran independientes de otros factores, como el tabaquismo, el consumo de alcohol y la obesidad, todas condiciones que pueden elevar las posibilidades de desarrollar tumores.

http://es.noticias.yahoo.com/10/2009...r-4b7b872.html

Cancer incidence in British vegetarians
T J Key1, P N Appleby1, E A Spencer1, R C Travis1, N E Allen1, M Thorogood2 and J I Mann3

Received 2 April 2009; Revised 24 April 2009; Accepted 24 April 2009; Published online 16 June 2009.

Background: Few prospective studies have examined cancer incidence among vegetarians.

Methods: We studied 61 566 British men and women, comprising 32 403 meat eaters, 8562 non-meat eaters who did eat fish ('fish eaters') and 20 601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use.

Results: There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07–1.20) in fish eaters and 0.36 (0.16–0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18–0.77) in fish eaters and 0.69 (0.45–1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36–1.81) in fish eaters and 0.47 (0.25–0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56–1.29) in fish eaters and 0.55 (0.39–0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73–0.93) in fish eaters and 0.88 (0.81–0.96) in vegetarians (P for heterogeneity=0.001).

Conclusion: The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters.

http://www.nature.com/bjc/journal/v1.../6605098a.html

[erfoud]

Bueno, eso se "soluciona" con llamamientos a comer menos carne roja y más de la otra. ¡Todos a jamar pollo! (no hay derechoor qué yo?)
Y fijáos cómo se suele abordar el tema: de una manera muy tenue, etérea, con suaves mensajes para comer menos carne roja,pero nunca de forma decidida y contundente. Y, por supuesto, ni hablar sobre recomendar explícitamente la dieta vegetariana, que hay poderosos intereses en la industria cárnica, y esto le haría pupa...
Conclusión: puajjj por la repugnante connivencia entre los grupos cárnico-lácteos y los medios de manipulación

[margaly]

en esta web dice:

"El mensaje, tanto para la gente vegetariana como para los carnívoros, es que con este solo estudio todavía no tenemos suficiente evidencia para poder recomendar a la gente que deje de comer carne totalmente o que sólo consuma vegetales".

"Lo que hay que seguir haciendo es reducir el consumo de sal, de grasas saturadas y no comer demasiada carne" expresa el investigador.
http://www.bbc.co.uk/mundo/ciencia_t...iano_men.shtml

[Gyzmo]

A pesar de la veracidad de estos estudios.Como mucho consiguen que los Mc Donalds pongan cuatro lechugas en un bote y se autoproclamen defensores de la salud pública.

De todas formas, como fumador que soy, no me veo capaz de esgrimir el argumento del cancer para la defensa de una dieta vegetariana, me sentiría un poquillo hipócrita.