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Ver la versión completa : Carne y cáncer



sujal
09-dic-2008, 15:00
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
09-dic-2008, 15:05
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
09-dic-2008, 15:07
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
22-ene-2009, 02:07
Hola Sujal,

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

Un abrazo!

Fer

sujal
22-ene-2009, 09:11
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 (http://www.mancia.org/foro/nutricion/20783-nutricion-vegetariana.html) y de donde surgió la idea de este subforo. Desde aquí, gracias a krisnesh.:)

SofíaCC
22-ene-2009, 09:34
Muy buena esta información, gracias Sujal.

sujal
02-jul-2009, 10:18
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/10/20090701/tot-oesen-salud-vegetarianos-cancer-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/v101/n1/full/6605098a.html

erfoud
06-jul-2009, 12:43
Bueno, eso se "soluciona" con llamamientos a comer menos carne roja y más de la otra. ¡Todos a jamar pollo! (no hay derecho:por 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
06-jul-2009, 13:17
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_tecnologia/2009/07/090701_cancer_vegetariano_men.shtml

Gyzmo
06-jul-2009, 13:19
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.

Machy
06-jul-2009, 20:16
Mi padre dejó de comer carne definitivamente cuanto tuvo un cancer de próstata.

Malatesta
06-jul-2009, 21:54
Mi padre dejó de comer carne definitivamente cuanto tuvo un cancer de próstata.
En una de las charlas del congreso vegetariano de Santander comentaron que la dieta vegetariana reducía las posibilidades de padecer cáncer de próstata, ya que con esta dieta se disminuía la cantidad de testosterona, que es lo que alimenta el cáncer de próstata.

Micorriza
21-feb-2010, 15:08
Más info (para los muy curiosos, hay miles de estudios referenciados al final)

Cancer Facts - Meat Consumption and Cancer Risk
The World Health Organization has determined that dietary factors account for at least 30 percent of all cancers in Western countries and up to 20 percent in developing countries. When cancer researchers started to search for links between diet and cancer, one of the most noticeable findings was that people who avoided meat were much less likely to develop the disease. Large studies in England and Germany showed that vegetarians were about 40 percent less likely to develop cancer compared to meat eaters.1-3 In the United States, researchers studied Seventh-day Adventists, a religious group that is remarkable because, although nearly all members avoid tobacco and alcohol and follow generally healthful lifestyles, about half of the Adventist population is vegetarian, while the other half consumes modest amounts of meat. This fact allowed scientists to separate the effects of eating meat from other factors. Overall, these studies showed significant reductions in cancer risk among those who avoided meat.4 In contrast, Harvard studies showed that daily meat eaters have approximately three times the colon cancer risk, compared to those who rarely eat meat.

A number of hypotheses have been advanced to explain the connection between meat consumption and cancer risk. First, meat is devoid of fiber and other nutrients that have a protective effect. Meat also contains animal protein, saturated fat, and, in some cases, carcinogenic compounds such as heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH) formed during the processing or cooking of meat. HCAs, formed as meat is cooked at high temperatures, and PAHs, formed during the burning of organic substances, are believed to increase cancer risk. In addition, the high fat content of meat and other animal products increases hormone production, thus increasing the risk of hormone-related cancers such as breast and prostate cancer.

In 2007, the American Institute for Cancer Research (AICR) published their second review of the major studies on food, nutrition, and cancer prevention. For cancers of the oesophagus, lung, pancreas, stomach, collorectum, endometrium, and prostate, it was determined that red meat (beef, pork, or lamb) and processed meat consumption possibly increased cancer risk. For colorectal cancer, a review of the literature determined that there is convincing scientific evidence that red meat increased cancer risk and that processed meat, saturated/animal fat, and heavily cooked meat were also convincing of increased risk.5

Carcinogenic Compounds in Cooked Meat

Heterocyclic Amines
HCAs, a family of mutagenic compounds, are produced during the cooking process of many animal products, including chicken, beef, pork, and fish. Even meat that is cooked under normal grilling, frying, or oven-broiling may contain significant quantities of these mutagens.6,7,8 The longer and hotter the meat is cooked, the more these compounds form. In some studies, grilled chicken has formed higher concentrations of these cancer-causing substances than other types of cooked meat.9

The major classes of heterocyclic amines include amino-imidazo-quinolines, or amino-imidazo-quinoxalines (collectively called IQ-type compounds), and amino-imidazo-pyridines such as PhIP. IQ-type compounds and PhIP are formed from creatine or creatinine, specific amino acids, and sugars.10 All meats (including fish) are high in creatine, and HCA formation is greatest when cooking meat at high temperatures, as is most common with grilling or frying. Consumption of well-done meat and PhIP has been associated with increased risk of breast cancer and colon cancer, as discussed in greater detail below. A recent case-control study at the University of Utah that included 952 subjects with rectal cancer and 1205 controls found that men and women with the highest consumption of processed or well-cooked meat had an increased risk of rectal cancer.11

Polycyclic Aromatic Hydrocarbons

Grilling or broiling meat over a direct flame results in fat dropping on the hot fire and the production of polycyclic aromatic hydrocarbon-containing flames. Polycyclic aromatic hydrocarbons (PAHs) adhere to the surface of food, and the more intense the heat, the more PAHs are present.5 They are widely believed to play a significant role in human cancers.12 A fairly consistent association between grilled or broiled, but not fried, meat consumption and stomach cancer implies that dietary exposure to PAHs may play a role in the development of stomach cancer in humans.5

Breast Cancer

Countries with a higher intake of fat, especially fat from animal products, such as meat and dairy products, have a higher incidence of breast cancer.13,14,15 In Japan, for example, the traditional diet is much lower in fat, especially animal fat, than the typical western diet, and breast cancer rates are low. In the late 1940s, when breast cancer was particularly rare in Japan, less than 10 percent of the calories in the Japanese diet came from fat.16 The American diet is centered on animal products, which tend to be high in fat and low in other important nutrients, with 30 to 35 percent of calories coming from fat. When Japanese girls are raised on westernized diets, their rate of breast cancer increases dramatically. Even within Japan, affluent women who eat meat daily have an 8.5 times higher risk of breast cancer than poorer women who rarely or never eat meat.17 One of the proposed reasons is that fatty foods boost the hormones that promote cancer.

According to new findings from the Shanghai Women's Health Study, soy food intake provides protection against premenopausal breast cancer when consumed during adolescence and as an adult. The usual dietary intake of 73,223 Chinese women during adulthood and adolescence was assessed after a mean follow-up of 7.4 years. Those with the highest intake of soy protein or isoflavone versus those with the lowest had about half the risk of premenopausal breast cancer regardless of age at time of consumption. No significant association with soy foods was found for postmenopausal breast cancer.18

The consumption of high-fat foods such as meat, dairy products, fried foods, and even vegetable oils causes a woman’s body to make more estrogens, which encourage cancer cell growth in the breast and other organs that are sensitive to female sex hormones. This suggests that, by avoiding fatty foods throughout life, hormone-related cancer risk decreases. A 2003 study, published in the Journal of the National Cancer Institute, found that when girls ages eight to ten reduced the amount of fat in their diet—even very slightly—their estrogen levels were held at a lower and safer level during the next several years. By increasing vegetables, fruits, grains, and beans, and reducing animal-derived foods, the amount of estradiol (a principal estrogen) in their blood dropped by 30 percent, compared to a group of girls who did not change their diets.19

Harvard researchers recently conducted a prospective analysis of 90,655 premenopausal women, ages 26 to 46, enrolled in the Nurses’ Health Study II and determined that intake of animal fat, especially from red meat and high-fat dairy products, during premenopausal years is associated with an increased risk of breast cancer. Increased risk was not associated with vegetable fats.20

In addition, researchers at the Ontario Cancer Institute conducted a meta-analysis of all the case-control and cohort studies published up to July 2003 that studied dietary fat, fat-containing foods, and breast cancer risk. Case-control and cohort study analyses yielded similar risk results, with a high total fat intake associated with increased breast cancer risk. Significant relative risks for meat and saturated fat intake also emerged, with high meat intake increasing cancer risk by 17 percent and high saturated fat intake increasing cancer risk by 19 percent.21

Several studies show meat intake to be a breast cancer risk factor, even when confounding factors, such as total caloric intake and total fat intake, are controlled.22,23 Part of the reason may be that meat becomes a source of carcinogens and/or mutagens, such as HCAs, that are formed while cooking meat at high temperatures. A review of HCAs showed that certain HCAs are distributed to the mammary gland and that humans can activate HCAs metabolically.24 As a consequence, frequent meat consumption may be a risk factor for breast cancer.22

Micorriza
21-feb-2010, 15:08
Colorectal Cancer

As with breast cancer, frequent consumption of meat, particularly red meat, is associated with an increased risk of colon cancer.25,26 Total fat and saturated fat, which tend to be substantially higher in animal products than in plant-derived foods, and refined sugar, all heighten colon cancer risks. At Harvard University, researchers zeroed in on red meat, finding that individuals eating beef, pork, or lamb daily have approximately three times the colon cancer risk, compared to people who generally avoid these products.26,27 A review of 32 case-control and 13 cohort studies concluded that meat consumption is associated with an increase in colorectal cancer risk, with the association being more consistently found with red meat and processed meat.12 And, in the recently published Cancer Prevention Study II, involving 148,610 adults followed since 1982, the group with the highest red meat and processed meat intakes had approximately 30 to 40 percent and 50 percent higher colon cancer risk, respectively, compared to those with lower intakes.28 In this study, high red meat intake was defined as 3 ounces of beef, lamb, or pork for men and 2 ounces for women daily, the amount in a typical hamburger. High processed meat intake (ham, cold cuts, hot dogs, bacon, sausage) was defined as 1 ounce eaten 5 or 6 times a week for men, and 2 or 3 times a week for women—the amount in one slice of ham. In addition, earlier studies have also indicated that those consuming white meat, particularly chicken, have approximately a threefold higher colon cancer risk, compared to vegetarians.29

Secondary bile acids are probably part of the problem. In order to absorb fat, the liver makes bile, which it stores in the gallbladder. After a meal, the gallbladder sends bile acids into the intestine, where they chemically modify the fats eaten so they can be absorbed. Unfortunately, bacteria in the intestine turn these bile acids into cancer-promoting substances called secondary bile acids. Meats not only contain a substantial amount of fat; they also foster the growth of bacteria that cause carcinogenic secondary bile acids to form.

Cooking methods that promote the formation of HCAs are believed to play a significant role in colorectal cancer risk. A case-control study in North Carolina that analyzed meat intake by level of doneness, cooking method, and estimated intake of HCAs in 620 colon cancer patients and 1038 controls, found that not only was red meat intake positively associated with colon cancer risk, but also pan-frying was the riskiest way to prepare meat due to high HCA formation.30 Confirmation of the link between frying and colorectal cancer risk was adduced in the review mentioned above, where high frying temperature was found to increase colon cancer risk almost twofold, and rectal cancer risk by 60 percent.12

Colorectal cancer is steadily becoming more common among young adults, according to an American Cancer Society analysis. Incidence rates among adults ages 20 to 49 increased 1.5 percent per year in men and 1.6 percent per year in women from 1992 to 2005. The increase may be tied to rising rates of obesity, a major risk factor for colorectal cancer. Increased consumption of meat (especially in fast food) over the past three decades could also be a key factor. Previous studies have suggested that diets free of red and processed meats and rich in plant-based foods may significantly reduce colorectal cancer risk.31

Prostate Cancer

Prostate cancer is one of the leading cancers among men in the U.S., and researchers have explored a number of possible dietary factors contributing to prostate cancer risk. These include dietary fat, saturated fat, dairy products, and meat, as well as dietary factors that may decrease risk, such as the consumption of carotenoids and other antioxidants, fiber, and fruit. As with breast cancer risk, a man’s intake of dietary fat, which is abundant in meat and other animal products, increases testosterone production, which in turn increases prostate cancer risk. One of the largest nested case-control studies, which showed a positive association between prostate cancer incidence and red meat consumption, was done at Harvard University in an analysis of almost 15,000 male physicians in the Physicians’ Health Study.32 Although this study primarily analyzed plasma fatty acids and prostate cancer risk, the authors found that men who consumed red meat at least five times per week had a relative risk of 2.5 for developing prostate cancer compared to men who ate red meat less than once per week. The most comprehensive dietary cohort study on diet and prostate cancer risk reported on nearly 52,000 health professionals in Harvard’s Health Professionals Follow-Up Study, which completed food frequency questionnaires in 1986.33 The report, based on 3 to 4 years of follow-up data, found a statistically significant relationship between higher red meat intake and the risk of prostate cancer, with red meat as the food group with the strongest positive association with advanced prostate cancer. These and other study findings suggest that reducing or eliminating meat from the diet reduces the risk of prostate cancer.34

A new review published in the Journal of Human Nutrition and Dietetics assessed whether certain modifications in diet have a beneficial effect on the prevention of prostate cancer. Results suggest that a diet low in fat, red meat, dairy, and calcium, yet high in fruits and vegetables is beneficial in preventing and treating prostate cancer. Consumption of highly processed or charcoaled meats, dairy products, and fats seemed to be correlated with prostate cancer.35

Other Cancers

Although not as extensively studied as breast, colon, and prostate cancer risk, a number of studies have concluded that meat consumption may play a significant role in kidney and pancreatic cancer risk. Three of eight case-control studies examining the relationship between renal cell carcinoma and meat consumption found a statistically significant increase in risk with a high consumption of meat. In addition, a prospective study in Japan found that people consuming meat daily had higher death rates from kidney cancer than those eating meat less frequently.5

Red meat and high glycemic index foods could be risk factors for kidney cancer, according to a 2009 study in the Journal of the American Dietetic Association. Researchers studied food questionnaires for 335 people with renal cell carcinoma, the most common form of kidney cancer, and 337 healthy controls. They found that men and women who ate red meat five or more times a week were more than four times as likely to develop the disease, compared to those who consumed red meat less than once a week. The study also found that white bread, white potatoes, and other high glycemic index foods increased the cancer risk threefold. High glycemic index foods affect insulin-like growth factors, which impact tumor development.36

Pancreatic cancer is relatively uncommon, yet it is frequently fatal, with fewer than 20 percent of cases surviving for one full year. Daily meat intake has been shown to be associated with increased pancreatic cancer risk in a number of prospective, cohort, and case-control studies.5 Some of these studies have singled out beef and pork consumption and have concluded there is a higher risk for pancreatic cancer with a higher intake of these foods.5

According to a new study, fat from red meat and dairy products is associated with increased risk of pancreatic cancer. As part of the National Institutes of Health-AARP Diet and Health Study, researchers followed and analyzed the diets of more than 525,000 participants to determine whether there is an association between dietary fat and pancreatic cancer. This same study found no association between plant-food fat and pancreatic cancer.37

A recent study in the British Journal of Cancer found that vegetarians are 12 percent less likely to develop cancer than meat-eaters. After following 61,000 meat-eaters and vegetarians for over 12 years, researchers also discovered that cancers of the blood—such as leukemia, multiple myeloma, and non-Hodgkin lymphoma—were drastically reduced by as much as 45 percent for those following a vegetarian diet. Although this study points to an overall reduced risk, this may well be an underestimate of the benefit of a vegetarian diet. Previous studies have shown as much as a 40 percent reduced risk for all cancers.38

Conclusion

Two themes consistently emerge from studies of cancer from many sites: vegetables and fruits help to reduce risk, while meat, animal products, and other fatty foods are frequently found to increase risk. Consumption of dietary fat drives production of hormones, which, in turn, promotes growth of cancer cells in hormone-sensitive organs such as the breast and prostate. Meat is devoid of the protective effects of fiber, antioxidants, phytochemicals, and other helpful nutrients, and it contains high concentrations of saturated fat and potentially carcinogenic compounds, which may increase one’s risk of developing many different kinds of cancer.

Vegetarian diets and diets rich in high-fiber plant foods such as whole grains, legumes, vegetables, and fruits offer a measure of protection.5 Fiber greatly speeds the passage of food through the colon, effectively removing carcinogens, and fiber actually changes the type of bacteria that is present in the intestine, so there is reduced production of carcinogenic secondary bile acids. Plant foods are also naturally low in fat and rich in antioxidants and other anti-cancer compounds. Not surprisingly, vegetarians are at the lowest risk for cancer and have a significantly reduced risk compared to meat-eaters.39

Micorriza
21-feb-2010, 15:10
References
1. Thorogood M, Mann J, Appleby P, McPherson K. Risk of death from cancer and ischaemic heart disease in meat and non-meat eaters. Br Med J. 1994;308:1667-1670.
2. Chang-Claude J, Frentzel-Beyme R, Eilber U. Mortality patterns of German vegetarians after 11 years of follow-up. Epidemiology. 1992;3:395-401.
3. Chang-Claude J, Frentzel-Beyme R. Dietary and lifestyle determinants of mortality among German vegetarians. Int J Epidemiol. 1993;22:228-236.
4. Barnard ND, Nicholson A, Howard JL. The medical costs attributable to meat consumption. Prev Med. 1995;24:646-655.
5. World Cancer Research Fund. Food, nutrition, physical activity, and the prevention of cancer: A global perspective. American Institute of Cancer Research. Washington, DC:2007.
6. Skog KI, Johansson MAE, Jagerstad MI. Carcinogenic heterocyclic amines in model systems and cooked foods: a review on formation, occurrence, and intake. Food and Chem Toxicol. 1998;36:879-896.
7. Robbana-Barnat S, Rabache M, Rialland E, Fradin J. Heterocyclic amines: occurrence and prevention in cooked food. Environ Health Perspect. 1996;104:280-288.
8. Thiebaud HP, Knize MG, Kuzmicky PA, Hsieh DP, Felton JS. Airborne mutagens produced by frying beef, pork, and a soy-based food. Food Chem Toxicol. 1995;33(10):821-828.
9. Sinha R, Rothman N, Brown ED, et al. High concentrations of the carcinogen 2-amino-1-methyl-6-phenylimidazo-[4,5] pyridine [PhlP] occur in chicken but are dependent on the cooking method. Cancer Res. 1995;55:4516-4519.
10. Jagerstad M, Skog K, Grivas S, Olsson K. Formation of heterocyclic amines using model systems. Mutat Res. 1991;259(3-4):219-233.
11. Murtaugh MA, Ma KN, Sweeney C, Caan BJ, Slattery ML. Meat Consumption patterns and preparation, genetic variants of metabolic enzymes, and their association with rectal cancer in men and women. J Nutr. 2004;134(4):776-784.
12. Norat T, Riboli E. Meat consumption and colorectal cancer: a review of epidemiologic evidence. Nutr Rev. 2001;59(2):37-47.
13. Armstrong B, Doll R. Environmental factors and cancer incidence and mortality in different countries, with special reference to dietary practices. Int J Cancer. 1975;15:617-631.
14. Carroll KK, Braden LM. Dietary fat and mammary carcinogenesis. Nutrition and Cancer. 1985;6:254-259.
15. Rose DP, Boyar AP, Wynder EL. International comparisons of mortality rates for cancer of the breast, ovary, prostate, and colon, and per capita food consumption. Cancer. 1986;58:2363-2371.
16. Lands WEM, Hamazaki T, Yamazaki K, et al. Changing dietary patterns. Am J Clin Nutr. 1990;51:991-993.
17. Hirayama T. Epidemiology of breast cancer with special reference to the role of diet. Prev Med. 1978;7:173-195.
18. Sang-Ah Lee, Xiao-Ou Shu, Honglan Li, et. al., Adolescent and adult soy food intake and breast cancer risk: results from the Shanghai Women's Health Study. Am J Clin Nutr. 2009; 89: 1920-1926.
19. Dorgan JF, Hunsberger SA, McMahon RP, et al. Diet and sex hormones in girls: findings from a randomized controlled clinical trial. J Natl Cancer Inst. 2003;95:132-141.
20. Cho E, Spiegelman D, Hunter DJ, et al. Premenopausal fat intake and risk of breast cancer. J Natl Cancer Inst. 2003;95:1079-1085.
21. Boyd NF, Stone J, Vogt KN, Connelly BS, Martin LJ, Minkin S. Dietary fat and breast cancer risk revisited: a meta-analysis of the published literature. Br J Cancer. 2003;89(9):1672-1685.
22. De Stefani E, Ronco A, Mendilaharsu M, Guidobono M, Deneo-Pellegrini H. Meat intake, heterocyclic amines, and risk of breast cancer: a case-control study in Uruguay. Cancer Epidemiol Biomarkers Prev. 1997;6(8):573-581.
23. Matos EL, Thomas DB, Sobel N, Vuoto D. Breast cancer in Argentina: case-control study with special reference to meat eating habits. Neoplasma. 1991;38(3):357-366.
24. Snyderwine EG. Some perspectives on the nutritional aspects of breast cancer research. Food-derived heterocyclic amines as etiologic agents in human mammary cancer. Cancer. 1994;74(3 suppl):1070-1077.
25. Singh PN, Fraser GE. Dietary risk factors for colon cancer in a low-risk population. Am J Epidemiol. 1998;148(8):761-74.
26. Giovannucci E, Rimm EB, Stampfer MJ, Colditz GA, Ascherio A, Willett WC. Intake of fat, meat, and fiber in relation to risk of colon cancer in men. Cancer Res. 1994;54(9):2390-2397.
27. Willett WC, Stampfer MJ, Colditz GA, Rosner BA, Speizer FE. Relation of meat, fat, and fiber intake to the risk of colon cancer in a prospective study among women. N Engl J Med. 1990;323:1664-1672.
28. Chao A, Thun MJ, Connell CJ, et al. Meat consumption and risk of colorectal cancer. JAMA. 2005;293:172-82.
29. Fraser GE. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am J Clin Nutr. 1999;70(suppl):532S-538S.
30. Butler LM, Sinha R, Millikan RC, Martin CF, Newman B, Gammon MD, Ammerman AS, Sandler RS. Heterocyclic amines, meat intake, and association with colon cancer in a population-based study. Am J Epidemiol. 2003;157(5):434-445.
31. Siegel RL, Jemal A, Ward EM. Increase in incidence of colorectal cancer among young men and women in the United States. Cancer Epidemiol Biomarkers Prev. 2009;18:1695-1698.
32. Gann PH, Hennekens CH, Sacks FM, Grodstein F, Giovannucci EL, Stampfer MJ. Prospective study of plasma fatty acids and risk of prostate cancer. J Natl Cancer Inst. 1994;86(4):281-286.
33. Giovannucci E, Rimm EB, Colditz GA, Stampfer MJ, Ascherio A, Chute CC, Willett WC. A prospective study of dietary fat and risk of prostate cancer. J Natl Cancer Inst. 1993;85(19):1571-1579.
34. Kolonel LN. Nutrition and prostate cancer. Cancer Causes Control. 1996;7(1):83-44.
35. Ma RW, Chapman K. A systematic review of the effect of diet in prostate cancer prevention and treatment. J Hum Nutr Diet. 2009;22(3):187-1899; quiz 200-202. Epub 2009 Apr 1.
36. Dolwick Grieb SM, Theis RP, et al. Food groups and renal cell carcinoma: results

from a case-control study. J Am Diet Assoc. 2009;109:656-667.
37. Thiébaut ACM, Jia L, Silverman DT, et al. Dietary fatty acids and pancreatic cancer in the NIH-AARP Diet and Health Study. J Natl Cancer Inst. 2009;101:1001-1011.
38. Key TJ, Appleby PN, Spencer EA, et. al. Cancer incidence in British vegetarians. British Journal of Cancer. 2009;101:192–197.
39. Phillips RL. Role of lifestyle and dietary habits in risk of cancer among Seventh-day Adventists. Cancer Res. 1975;35(suppl):3513-3522.


Fuente: Cancer project (http://www.cancerproject.org/diet_cancer/facts/meat.php)

VeG
21-feb-2010, 16:59
¿Alguien sabe cual es la razón por la cual la proteína de origen animal (carnes, lácteos, etc) hace aumentar el insulin like -growth factor, mientras que la de origen vegetal no lo hace?

vegaluz
19-mar-2010, 13:11
Interesante artículo The cancer Project y la asociación americana del cancer, asi que quien no quiera hacerse vegetariano por amor a los animales al menos que lo haga por amor a si mismo ;-)

http://www.cancerproject.org/espanol/CP_ACS.pdf

http://www.cancerproject.org/protective_foods/spanish.php

Cancer Prevention and Survival: La Comida Vegetariana Poderosa para la Salud
La dieta vegetariana ha sido propuesta por muchos, desde filósofos como Platón y Nietzsche hasta líderes políticos como Benjamín Franklin y Ghandi, e ídolos modernos como Paul McCartney y Bob Marley. La ciencia también apoya la dieta vegetariana, existiendo muchos estudios que demuestran sus beneficios para la salud.

Ser “vegetariano” significa no comer producto animal alguno, incluyendo todo tipo de pescado o aves. Los vegetarianos que consumen huevo y leche o sus derivados se denominan “ovo-lacto-vegetarianos” (ovo=huevo, lacto= leche). Quienes evitan por completo todo producto de origen animal se llaman vegetarianos puros o “vegans.” Se ha demostrado que los ovo-lacto-vegetarianos son más saludables que los que comen carne, y los vegans lo son más que los ovo-lacto-vegetarianos.

La Prevención de Cáncer

La dieta vegetariana previene el cáncer. Muchos estudios epidemiológos y clínicos muestran que los vegetarianos tienen un riesgo cincuenta porciento menor de morir de cáncer que los no-vegetarianos.1 De forma similar, el número de casos de cáncer de mama es mucho menor en países como China, donde se come una dieta basada en vegetales. Es interesante que las mujeres japonesas que comen una dieta no vegetariana, en vez de su dieta tradicional, tienen ocho veces mayor riesgo de desarrollar un cáncer de mama.2 Los vegetarianos son también menos afectados por el cáncer de colon.1 Lo que se come del animal casi siempre es alto en grasa y muy bajo en fibra. La carne y productos lácteos contribuyen a muchos tipos de cáncer, incluyendo los de colon, mama, próstata y otros órganos. El cáncer de colon ha sido directamenta asociado al consumo de carne. Las dietas ricas en grasa estimulan la producción de estrógenos, en particular de estradiol, altos niveles del cual se asocian al cáncer de mama. Un estudio reciente demostró la asociación entre el consumo de productos lácteos y un mayor riesgo de desarrollar cáncer de ovario. El proceso de digerir la lactosa (azúcar de la leche) para convertirla en galactosa, evidentemente daña el ovario.3

Los vegetarianos evitan la grasa animal—asociada al cáncer —y consumen mucha fibra y vitaminas, buenos preventivos de esta enfermedad. El análisis de la sangre de los vegetarianos demuestra un nivel más elevado de leucocitos especializados en atacar las células cancerosas.4

La Lucha contra las Enfermedades del Corazón

La dieta vegetariana previene también las enfermedades cardíacas. La carne es la fuente principal de grasa saturada, y casi la única fuente principal de grasa saturada, y casi la unica fuente de colesterol en la dieta. Los vegetarianos evitan estos productos de alto riesgo. Adicionalmente, la carne no contiene fibra, que ayudaría a reducir los niveles de colesterol.5 Un estudio demostró incluso que una dieta vegetariana—pobre en grasas y rica en fibra—asociada a modificaciones del estilo de vida—como el ejercicio y el dejar de fumar—, podía revertir el proceso de aterosclesosis.6

El Control de la Hipertensión

Ya desde comienzos de siglo los especialistas en nutrición notaron que los que no comían carne mantenían una presión arterial màs baja.7 También se descubrió que simplemente dos semanas de dieta vegetariana bastaban para reducir la presión,8 independientemente de los niveles de sodio en la dieta.

La Prevención y la Reversión de la Diabetes

La diabetes no insulino-dependiente puede ser controlada, y a veces curada, con una dieta vegetariana baja en grasas y ejercicio diario. La dieta pobre en grasas pero rica en fibras y carbohidratos complejos permite una acción más efectiva de la insulina, con un control más fácil de los niveles de azúcar en la sangre. En la diabetes insulino-dependiente, la dieta vegetariana no elimina la necesidad de inyectar insulina, pero permite reducir la cantidad de este medicamento. Hay científicos que piensan que la diabetes insulino-dependiente puede ser causada por una reacción del cuerpo contra las proteínas animales.

Litiasis Biliar y Renal, Osteoporosis

Se ha demostrado que la dieta vegetariana reduce el riesgo de formación de cálculos. Las dietas ricas en proteínas, especialmente animales, inducen la eliminación por la orina de calcio y los ácidos oxálico y úrico, que son precisamente los componentes fundamentales de los cálculos renales. Algunos investigadores ingleses aconsejan que las personas propensas a la litiasis renal deben seguir una dieta vegetariana.9 De forma similar, se ha encontrado una relación entre la formación de cálculos biliares y la ingestión de grandes cantidades de colesterol y grasa, típico de las dietas cárnicas.

Por razones semejantes, los vegetarianos tienen un menor riesgo de padecer de osteoporosis. Como los productos animales inducen la decalcificación del hueso, el comer carne favorece la osteoporosis. Esta enfermedad es menos común en países donde predomina el vegetarianismo, cuando se les compara con Estados Unidos,10 aún cuando en este último país el consumo de calcio es mayor.

vegaluz
19-mar-2010, 13:12
Asma Bronquial

Un estudio sueco de 1985 mostró que los asmáticos que logran mantener durante un año una dieta vegetariana experimentan una dramática reducción en la frecuencia y severidad de sus ataques, y en su consumo de medicamentos.11 Veintidós de las veinticuatro personas estudiadas constataron una mejoría en su enfermedad.

Preocupaciones

Algunos se preocupan de que una dieta vegetariana no pueda cumplir con los requisitos nutricionales del cuerpo humano. La realidad es que es fácil mantener una nutrición adecuada, a través de una dieta vegetariana, que garantiza una cantidad suficiente de proteínas. Además, no es necesaria una combinación especial de comidas para obtener las proteínas necesarias, pues cualquier combinación vegetariana lo garantiza. Es cierto que la dieta vegetariana tiene menor contenido proteico que una dieta basada en carnes, pero esto es una ventaja. El exceso de proteínas se asocia, como ya vimos, con la formación de cálculos renales, la osteoporosis, y posiblemente con las enfermedades cardíacas y el cáncer. Una dieta basada en legumbres, granos, frutas y vegetales, contiene la cantidad necesaria de proteínas. No es necesaria la excesiva ingestión proteica de las dietas cárnicas.

Es fácil obtener calcio a partir de una dieta vegetariana, pues lo contienen muchos vegetales verde-oscuros y frijoles. Los granos, legumbres y frutas contienen una importante cantidad de hierro.

La Vitamina B12

Quienes no comen nada de carne, huevos ni productos lacteos, tienen una mayor dificultad en obtener la necesaria cantidad de vitamina B12. La bacteria que produce esta vitamina crece en la tierra y se encuentra entre las raíces, así que un vegetariano puede obtenerle ingiriendo el miso y el tempeh que se comen abundantemente en los países asiáticos. La industrialización y normas higiénicas modernas han conducido a una reducción en las fuentes de vitamina B12, que sí abunda en la carne donde se encuentra la bacteria necesaria para ello.

Son pocos los vegetarianos que desarrollan un déficit de B12. Sin embargo, es mejor contar con una fuente adicional de la misma, para lo que se recomiendan cereales o leche de soya fortificados, o vitaminas. Esto es especialmente importante para la mujer embarazada y la que está lactando.

Preocupaciones Especiales: El Embarazo, los Lactantes y Niøos en General

Las necesidades nutricionales aumentan con el embarazo. La Asociación Dietética Americana ha encontrado que la dieta vegetariana contiene todo lo necesario para un embarazo, pero que tanto las embarazadas como las que lactan deben suplementar su dieta con vitaminas B12 y D. La mayoría de los médicos también recomienda suplementos de ácido fólico y hierro en estos casos, pero los vegetarianos consumen una mayor cantidad de acido folico que quienes consumen dietas cárnicas.

Las mujeres vegetarianas sufen menos pre-eclampsia durante el embarazo, y producen una leche màs pura después. El análisis de la leche de una madre vegetariana muestra un menor contenido de contaminantes del medio ambiente.12 Se ha encontrado que en las familias con alta incidencia de problemas alérgicos, si la mujer mantiene una dieta vegetariana durante el embarazo, logra reducirse la incidencia de alergia en su descendencia.13 En las que se mantienen tomando leche de vaca, sin embargo, le pasan a su bebé lactante los anticuerpos de este animal, que provocan en el niño problemas alérgicos y cólicos.

Los niños logran una buena nutrición con la comida vegetariana, debiendo sólo cuidarse de administrarles un suplemento de vitamina B12. La dieta vegetariana prolonga la vida. Los niños vegetarianos pueden crecer más lentamente, alcanzar más tardíamente la pubertad. Esto es algo my deseable para las mujeres pues la menarquia precoz es un factor de riesgo para el desarrollo de cáncer mamario. Además, este más lento desarrollo infantil y puberal prolonga la expectativa de vida.

Referencias

1. Phillips RL. Role of lifestyle and dietary habits in risk of cancer among Seventh-Day Adventists. Cancer Res (Suppl) 1975;35:3513-22.
2. Trichopoulos D, Yen S, Brown J, Cole P, MacMahon B. The effect of westernization on urine estrogens, frequency of ovulation, and breast cancer risks: a study in ethnic Chinese women in the Orient and in the U.S.A. Cancer 1984;53:187-92.
3. Cramer DW, Harlow BL, Willett WC. Galactose consumption and metabolism in relation to the risk of ovarian cancer. Lancet 1989;2:66-71.
4. Malter M, Schriever G, Eilber U. Natural killer cells, vitamins, and other blood components of vegetarian and omnivorous men. Nutr Cancer 1989; 12:271-8.
5. Sacks FM, Castelli WP, Donner A, Kass EH. Plasma lipids and lipoproteins in vegetarians and controls. N Engl J Med 1975;292:1148-52.
6. Ornish D, Brown SE, Scherwitz LW. Can lifestyle changes reverse coronary heart disease? Lancet 1990;336:129-33.
7. Salie F. Influence of vegetarian food on blood pressure. Med Klin 1930;26:929-31.
8. Donaldson AN. The relation of protein foods to hypertension. Calif West Med 1926;24:328-31.
9. Robertson WG, Peacock M, Heyburn PJ. Should recurrent calcium oxalate stone formers become vegetarians? Br J Urol 1979;51:427-31.
10. Hegsted DM. Calcium and osteoporosis. J Nutr 1986;116:2316-9.
11. Lindahl O, Lindwall L, Spangberg A, Stenram A, Ockerman PA. Vegan regimen with reduced medication in the treatment of bronchial asthma. J Asthma 1985;22:45-55.
12. Hergenrather J, Hlady G, Wallace B, Savage E. Pollutants in breast milk of vegetarians (letter). N Engl J Med 1981;304:792.
13. Allergies in infants are linked to mother's diets. New York Times, 30 August 1990.

sujal
14-ago-2010, 12:29
Well-cooked meat 'may increase risk of bladder cancer'

Read more: http://www.dailymail.co.uk/health/article-1267409/Well-cooked-meat-increase-risk-bladder-cancer.html#ixzz0wZwwCcLG

El consumo de carne bien cocinada mostró estar ligado a un riesgo casi del doble de desarrollar cáncer de vejiga. Cocinar la carne a altas temperaturas produce sustancias cancerígenas llamadas aminos heterocíclicos. Los participantes en el estudio quienes más consumían tocineta, chuletas de cerdo, pollo frito y pescado frito también mostraron tener un riesgo más alto.

Vegetarian Diet Vs. Cancer

Read more: http://usaeu.net/2010/08/vegetarian-diet-vs-cancer/

Hera_malove
09-sep-2010, 13:37
Para que luego digan que el tabaco es el único causante del cáncer... ¬¬

Ecomobisostrans
22-sep-2015, 00:21
De nuevo la $i€n$ia "descubriendo" cosas cuando mas interesa... :rolleyes:

Los científicos han descubierto por qué Finalmente Consumir carne roja causa el cáncer
21 de septiembre 2015 | (Está traducido del inglix pero se entiende bastante bien)

https://translate.google.es/translate?sl=en&tl=es&js=y&prev=_t&hl=es&ie=UTF-8&u=http%3A%2F%2Fanonhq.com%2Fscientists-have-finally-discovered-why-consuming-red-meat-causes-cancer%2F&edit-text=

Ecomobisostrans
26-oct-2015, 23:32
https://www.facebook.com/1500748463518570/photos/a.1507213639538719.1073741828.1500748463518570/1659229671003781/

https://scontent-mad1-1.xx.fbcdn.net/hphotos-xta1/v/t1.0-9/s720x720/12187654_1659229671003781_3057329924048074670_n.pn g?oh=853d2eb53dff2a353241f71636f3cc5d&oe=5688468A

¿Cuánto has tardado OMS para hacer oficial lo que infinidad de asociaciones de nutrición y dietética, así como reputadísimos profesionales de las mejores Universidades de medicina del planeta ya habían comunicado? ¿Por qué tanto tiempo? Ah sí, para proteger el negocio de violación, maltrato, mutilación, muerte y descuartizamiento de inocentes con cuyas vidas sostenéis el sistema más genocida de la historia.

Hoy damos un paso más. Claro que muchos seguirán pagando aún así por masacrarles, pero otros muchos dejarán de hacerlo, creerán más en el vegetarianismo y sumaremos más voces para defenderles. No lo hacemos sólo por salud - que también -, sino sobre todo por justicia.

ABOLICIÓN DEL HOLOCAUSTO ANIMAL

#NoComoAnimales

Marsupial
28-oct-2015, 02:08
Monsanto ha pasado a la ofensiva!!!!

Jorgekristo
28-oct-2015, 10:37
http://fdzeta.com/subir/images/pGDl.png

valentaina01
18-feb-2018, 21:19
Ciertamente está combrobado los grandes daño de la carne en nuestro cuerpo y sigen consumiendose toneladas. Así es el ser humano.

rufinagutierrez55
19-feb-2018, 19:51
Creo que la carne a partir de cierta edad tiene una relación directa con los Sintomas de hipertensión (http://presion-arterial.com/sintomas-de-hipertension/) y otras enfermedades. En mi caso me ha ido mejor cuando me he vuelto vegetariana.