viernes, diciembre 15, 2006

El consumo de leche de vaca y el cáncer, segunda parte

El blog Ciencia y Lejos ha publicado un post titulado "Cómo aprendimos rápidamente a usar la lactosa". Una vez que he leído ese interesante artículo, me he puesto en contacto con su autora, Azuara, y le he preguntado su opinión sobre la teoría que relaciona el consumo de leche de vaca con el cáncer y me ha respondido lo siguiente:


Tiene varios puntos para que sospeches de "artículos" como éste.Las fuentes... Sólo encontrarás este tipo de textos alarmistas en páginas muy concretas (vegetarianas y veganas), por supuesto sin fuentes y si las hay sospechosamente vagas. Nada de citar Nature o Science como el artículo anterior.Además cuando llegan mediante mensajes en cadena, la cosa todavía está más clara. Una rápida búsqueda en Google y todos lo resultados que hablan de cáncer y leche se refieren a esta misma mujer y su libro. ¿No hay más referencias?Ah, y de la página discovery salud no te creas nada, pero nada, nada... Alguna vez he hablado de ellos, porque dicen cosas bastante peligrosas en temas de salud.En cuanto al propio texto (avalado por una señora cuya diplomatura no existe "Medicina Tradicional China), es bastante pobre. No puedes hacer un estudio epidemiológico en el salón de tu casa y publicarlo tan alegremente. Me explico, ha tomado varios parámetros (los que le interesan):- Causa: Consumo de leche- Consecuencia: Cáncer de mama- Grupos a comparar: Occidentales vs Orientales¿No te parece que falta mucha información? Cuando hablamos de cáncer es muy difícil ceñirse a una sola causa. Su estudio podría haber afirmado tranquilamente que el alcohol causa cáncer de mama (porque los orientales también tienen más intolerancia al alcohol) o que la soja protege (quién sabe) o que los ojos rasgados son una ventaja.Cita varias sustancias como culpables del cáncer. Me parecen increíbles las cantidades industriales de IGF-1 que contiene la leche según el artículo. Y aunque así fuera, es un polipéptido, una proteína, se destruye en el estómago. Si fuera cierto, estaríamos tratando la diabetes con pastillas (ojalá). Se ha liado analizando los estudios que menciona: el nivel de IGF-1 se utiliza como una parte del diagnóstico de algunos tipos de cáncer, no es la causa del cáncer :-/ Me explico, para ver si el hígado está bien, se miden las transaminasas por ejemplo, pero las transaminasas no producen hepatitis, aumentan como consecuencia.Piensa que su descubrimiento "importante" como ella dice, no ha sido publicado en ninguna revista científica; no te digo ninguna importante, hay de muchas clases. Ha tenido que escribir un libro, para regocijo de vegetarianos...


Gracias a Azuara por tener el detalle de darme su opinión al respecto.

2 comentarios:

Azuara dijo...

de nada :) Ahí queda mi opinión para quien la quiera leer.

Sinceramente me parece una "falacia del tercer factor", quizá no intencionada (el cáncer de mama tiene un componente psicológico incluso mayor que otros tipos de cáncer más graves, y lo entiendo).

Hoy he leído un estudio que relaciona este tipo de cáncer con la terapia hormonal que se toma para combatir la menopausia. En teoría aumentaría el riesgo de cáncer. Si comparas con el anterior, este estudio se ha realizado con muchas más mujeres, durante más tiempo, y sobre todo es un estudio controlado. Y con todo, los investigadores no se atreven a decir que los resultados sean concluyentes.

Anónimo dijo...

Claro que hay estudios, mira....


Big mistake

One of the biggest mistakes made by doctors and nutritionists today is telling people to drink lots of milk and to eat lots of other dairy foods like cheese and yoghurt.

Milk and dairy foods cause lots of health problems, including cancer. I will give some details of these problems later. But first, let's take a look at how nutritionists think and understand how they come to make this big mistake.

The science of nutrition is very simplistic. Its logic goes like this: Our bones are made of calcium. Milk is rich in calcium. Therefore milk is good for our bones. Therefore milk is good for our health. Therefore all of us should drink lots of milk.

It seems to make sense. But this was exactly the same mistake nutritionists used to make regarding meat.

They used to tell us that our flesh is made of protein. Meat contains lots of protein. Therefore meat is good for health. Therefore we should all eat lots of meat.

And the people who followed such advice ended up with lots and lots of health problems, including heart disease, kidney failure, gout and various types of cancer.

The same sort of simplistic logic is now being applied to milk. Nutritionists never seem to learn from their past mistakes.

Because they never change their way of thinking. They look at what a food contains, rather than what the food does to us.

If you look at what milk contains, well, it contains lots of nutrition - protein, fats, sugars, vitamins and minerals, including plenty of calcium. You will reach the conclusion that milk is "the perfect food".

But if you at the effects of drinking lots of milk, you will realise that milk does more harm than good. A lot more harm than good.

Here's a brief summary of some of the more important scientific studies and observations about the harm caused by milk:

CANCER

The highest rates of female cancers (breast, womb and cervical cancers) in the world can be found in milk-producing / milk-drinking countries:

1. Denmark (139 per 100,000 population)
2. Scotland (136)
3. Hungary (129)
4. England / Wales (127)
5. Ireland (126)
6. New Zealand (124)
7. Northern Ireland (123)

Singapore ranks 18th (110), on par with the US.

- World Health Statistics Annuals, 1987-90
cited in The Cancer Prevention Diet, by Michio Kushi

Cancer of the lung, breast and colon increased 2 to 3 times among Japanese women between 1950 and 1975. During that period, milk consumption increased 15 times, meat, poultry and eggs climbed 7 1/2 times, and rice consumption dropped 70 percent.

- Y Kagawa, Preventive Medicine, 7:205-17, 1978

A study of 250 women with breast cancer in Vercelli, Italy, found that they tended to consume considerably more milk, high-fat cheese and butter than 499 healthy women.

- Paolo Toniolo et al, Journal of the National Cancer Institute, 81:278-86, 1989

A 1977 study based on 111 cases with prostate cancer and 111 hospital controls showed that the cancer patients consumed more high-fat foods, including beef, pork, eggs, cheeses, milk, creams, butter and margarine.

- I D Rotkin, Cancer Treatment Reports, 61:173-80, 1977

Harvard University researchers asked hundreds of women with ovarian cancer to record in detail what they normally ate. There was one thing that they had eaten much more frequently than women without cancer – dairy products, especially the supposedly “healthy” dairy products such as yoghurt and cottage cheese.

The problem is the milk sugar, not the milk fat, so it is not solved by non-fat products.

- Cramer D W, et al, Lancet, 2:66-71, 1989

A 16-nation study, based on WHO statistics, indicated that consumption of beef and dairy products increased the risks of lymphosarcoma by 70% and Hodgkin’s disease by 61%.

- A S Cunningham, Lancet, 2:1184-86, 1976

ALLERGIES

A teenage boy in hospital with muscular and skeletal pains, bronchial asthma, abdominal pains, headache and dark circles under the eyes experienced substantial improvement within 2 days when milk and chocolate were taken out of the diet. When milk was given to him again after 3 weeks, the pallor, dark circles and other symptoms returned.

- E G Weiberg, Annals of Allergy 31:209-11, 1973

ANAEMIA

Many studies have measured the blood iron levels of people with different diet-styles. Vegetarians consistently fared better in these tests than do meat eaters. The only people who run into trouble are the ones who eat a lot of dairy products, fatty foods, sugar and junk foods....

- John Robbins, Diet for a New America

ARTHRITIS

A 38-year-old woman had, for 11 years, been suffering from steadily worsening rheumatoid arthritis. Three weeks after doctors removed all dairy products from her diet, she showed signs of improvement. In four months, her arthritic symptoms had completely disappeared.

In the interest of scientific curiosity, she once again ate some cheese and milk. The next day, her joints were swollen, stiff and painful. Her symptoms again disappeared as she resumed her abstinence from dairy products.

- Parks A, British Medical Journal, 282:2027, 1981

ASTHMA

Twenty five patients with bronchial asthma were put on a strict vegetarian diet. They showed 71 percent improvement within 4 months, and 92 percent improvement within one year. The experimental diet avoided meat, dairy food, eggs, fish, sugar, chocolate, salt and other foods.

- O Lindahl et al, Journal of Asthma 22:45-55, 1985

CATARACTS

Populations that consume large amounts of dairy foods have a much higher incidence of cataracts.

The problem appears to be the milk sugar, lactose. In the digestive tract, lactose breaks down into two simple sugar molecules, glucose and galactose. When blood concentration of galactose increase, it can pass into the lens of the eye. . . (and) can lead to opacities of the lens.

Nursing children can generally handle galactose. As we age, many of us lose this capacity to break down galactose. There are even rare cases of genetic defects in which children cannot break down galactose. These children can form cataracts within the first year of life.

- Couet C et al, Journal of the American College of Nutrition 10(1):79-86, 1991

CRIME + DELINQUENCY

Researchers at the University of Washingtom found that juvenile deliquents drank a lot more milk. Male offenders consumed an average of 64 ounces of milk a day, while the control group consumed an average of 30 ounces. For girls, the figures were 35 and 17 ounces respectively.

In some cases, the researchers reported, “eliminating milk from the diet can result in dramatic improvement in behaviour, especially in hyperactive children.”

- Alexander Schauss, Diet, Crime & Delinquency

DIABETES

Cow’s milk protein can enter the infant’s bloodstream and stimulate the formation of antibodies which, in turn, destroy the pancreatic cells that produce insulin. Diabetes occurs when 80 - 90 percent of these cells are destroyed.

Researchers from Canada and Finland found high levels of antibodies to a specific cow’s milk protein in every one of 142 diabetic children they studied.

Antibodies can apparently form in response to even small quantities of cow’s milk. Cow’s milk protein can even reach a breast-feeding baby if the mother drinks milk.

- Scott F W, American Journal of Clinical Nutrition, 50:728-30, 1989

OSTEOPOROSIS

MILK ACTUALLY WORSENS OSTEOPORSIS!

Countries where dairy products are commonly consumed - the US and North European countries - actually have more osteoporosis than other countries. Milk does contain calcium, but diets that are high in protein, especially animal protein, causes the body to lose calcium.

- Hegsted R et al, Journal of Nutrition, 111:553-62, 1981

A study – funded by the US National Dairy Council for the purpose of showing the benefits of milk – showed that women continued to develop osteoporosis even when they drank an extra three 8-ounce glasses of low-fat milk every day for a year.

Scientists who conducted the tests said this was due to “the average 30% increase in protein intake during milk supplemtation.”

- Recker R, American Journal of Clinical Nutrition, 2:1061, 1974

The calcium in kale is more efficiently absorbed than the calcium in milk.

- Robert P Heaney & Connie Weaver,
American Journal of Clinical Nutrition, 51:656-57, 1990

Fuente: http://www.richardseah.com/naturalhealth/nomilk.html