Saturday, October 20, 2007

Eating meat and being healthy

I'm confused

Growing up I always believed that the best diet consisted of meat and 3 veges. Sometimes we might have fish, sometimes chicken - but usually red meat.

Last year, after hearing the publicity surrounding the CSIRO Wellbeing Diet book, I thought this confirmed my belief that red meat was good for - the book recommends lean red meat four times per week, fish twice per week and chicken once per week. I've been following the CSIRO diet believing that, not only will I be able to manage my weight, but also be healthy which is of course my primary interest. The CSIRO was criticized for having too much red meat in the diet however stood by the book and red meat quota.

I was very surprised when I read an article/transcript on the ABC Health website at http://www.abc.net.au/health/healthyliving/stories/2007/10/02/1899699.htm

In particular when I read "Vegetarians are generally a healthy bunch. Compared to meat eaters, they have less heart disease and cancer, lower blood pressure – and they're slimmer"

I found this amazing as it is contrary to everything I have heard - in fact I always thought that vegetarians were unhealthy - and needed to supplement their diet with meat substitutes to keep up with meat eaters. But this article not only says they are healthier that meat eaters but they have less disease and cancer!

Another quote from the article "What's more, red meat – which includes pork but not chicken – has been linked to a slightly higher risk of some cancers. And for processed meats like sausages – along with bacon, ham and salami – the cancer link is stronger ... What's not known is whether there's something in red meat that causes cancer or whether eating meat means there's less room in your diet for other foods that might help prevent cancer. It might be a bit of both."

This piqued my interest so further google searching found this article at http://news.bbc.co.uk/1/hi/health/4662934.stm which in part says "regular meat eaters are significantly more likely to develop bowel cancer", http://www.cancercouncil.com.au/editorial.asp?pageid=1861 says that "diets high in red meat are associated with a slight increase in risk of bowel cancer", http://www.goveg.com/cancer.asp says that "Vegetarians are about 40 percent less likely to get cancer than nonvegetarians, regardless of other risks such as smoking, body size, and socioeconomic status."

Even more worrying is this entry in Wikipedia at http://en.wikipedia.org/wiki/Red_meat#Cancer

"Recent studies indicate that red meat could pose a notable increase in cancer risk. Some studies have linked consumption of large amounts of red meat with breast cancer, colorectal cancer, lymphoma, bladder cancer and prostate cancer. Professor Sheila Bingham of the Dunn Human Nutrition Unit attributes this to the haemoglobin and myoglobin molecules which are found in red meat. She suggests these molecules, when ingested trigger a process called nitrosation in the gut which leads to the formation of carcinogens. Overall, the relative risk of developing a fatal cancer in non meat-eaters is 0.91 compared to people who eat red meat regularly.

Eating cooked red meat may increase the likelihood of cancer because carcinogenic compounds called heterocyclic amines are created during the cooking process. Heterocyclic amines may not explain why red meat is more harmful than other meat, however, as these compounds are also found in poultry and fish, which have not been linked to an increased cancer risk."

What's also amazing is that many foundations are saying that as these theories are still just theories then restricting meat to smaller serves and no more than 3 - 4 serves per week is OK .... This sounds like spin doctoring to me - maybe catering to the meat industry?


I'm confused

2 comments:

tardis3 said...

Since writing this article, following a report about meat in the UK, the media has given this issue quite a bit of publicity. From The Age newspaper - 2nd November 2007

Prepare to meat thy doom, says cancer report

BACON and egg breakfasts and salami sandwiches are off the menu for all those serious about avoiding cancer, a team of scientists has concluded in a study of all major contributors to the disease.

An analysis of more than 7000 cancer studies has found that up to 4 million cancers — or roughly a third of all cases — could be avoided each year if people followed 10 new lifestyle recommendations.

But the regime put forward by the World Cancer Research Fund seems onerous.

It said that cancer was between 30 and 40 per cent preventable, but only if we do such things as exercising for at least half an hour a day, staying slim throughout our adulthood, eating more vegetables, limiting our intake of red meat and alcohol and cutting out processed meat.

"What we're saying is that perhaps a third of cancers are diet-related. Cancer is largely preventable. It is a very positive message," said Sir Michael Marmot, from the University College London, who led a team of more than 200 scientists who trawled global research databases.

But the local meat industry said the report was "dangerously misleading" and ignored the fact that Australians typically eat their red meat lean and with lots of vegetables.

"The report's focus on fresh red meat doesn't make sense," said David Palmer, managing director of Meat & Livestock Australia. "Red meat consumption has fallen by about 20 per cent over the past 20 years, yet bowel cancer rates have risen some 6 per cent during this time."

The industry found some support in Cancer Council Australia chief Ian Olver, who said it was "probably OK to have three or four serves" of red meat each week. "The recommendations are just an ideal based on the current literature. But we wouldn't want people to take the message away that they can't eat any red meat at all," he said. "What we want to do is promote a healthy life, but we don't want people to go too far and try and cut out everything they think is harmful. Moderation is key."

Professor Olver said the analysis was nonetheless pivotal, because for the first time it put "solid evidence behind some of the things we suspected" were contributing to cancer rates.

"We now have the evidence that exercise is very important, that vegetables are very good for you and that some processed foods increase your chances of getting cancer, particularly bowel cancer."

The researchers defined processed meats as those that had been preserved by smoking, curing, salting or by the addition of preservatives. Ham, bacon, pastrami and salami are processed meats along with sausages, bratwursts, frankfurters, and hot dogs.

While mild alcohol consumption could be beneficial for other illnesses like heart disease, the researchers recommended that men should limit their intake to no more than two drinks a day and women to just one drink if they wanted to reduce their chances of cancer.

The study also singled out sugary drinks, and suggested people should consume even fruit juices — particularly processed ones — more sparingly.

Sir Michael said the "most striking thing to emerge" from the global study, the first since the same group published the original in 1997, was that the link between overweight and obese people and cancer rates was irrefutable. "Young adults should try not to put on weight throughout their adult life. They should stay as lean as possible."

Anonymous said...

CSIRO's best-selling diet 'ignores cancer concerns'

Matthew Ricketson
April 1, 2008

THE board of the CSIRO has received two reports of research linking red meat consumption with bowel cancer but the organisation continues to promote its bestselling book, the red-meat-heavy CSIRO Total Wellbeing Diet.

In April 2006, following the book's release in 2005, the board was told of an academic journal article written by three of its own scientists establishing that "diets high in red meat, processed meats and the dairy protein casein can significantly increase the risk of bowel cancer", according to documents released under freedom of information and published in the latest issue of The Monthly magazine, out today.

Late last year, the board was told of a joint study by the World Cancer Research Fund and the American Institute for Cancer Research noting that evidence linking consumption of red and processed meat to bowel cancer "was stronger now than in the mid 1990s" and was "deemed to be convincing".

The CSIRO Total Wellbeing Diet has been a runaway publishing success, selling more than 1 million copies, according to one of its co-authors, Dr Manny Noakes.

It has also drawn criticism for the amount of red meat, which is rich in protein, that it recommends people eat.

Some nutritionists have asked whether funding for research received by CSIRO from the meat and livestock industry influenced the recommended amount of red meat, a criticism Dr Noakes rejects.

She said yesterday: "We will continue to look at all the evidence. The WCRF report suggests one thing but we understand that a large study in the United States due to be released soon shows no relationship between red meat and colorectal cancer."

Colorectal cancer, also known as large bowel cancer, includes cancerous growths in the colon, rectum and appendix.

Dr Noakes and her co-author, Dr Peter Clifton, made some changes when the second edition of The CSIRO Total Wellbeing Diet was released in late 2006, noting that "people who eat lots of red meat but also eat lots of fish are not at any increased risk (of colorectal cancer)".

The Monthly article, by Geoff Russell, a freelance journalist and honorary committee member of Animal Liberation, says that the WCRF report had found inconclusive the evidence that eating fish decreased the risk of bowel cancer.

The CSIRO book recommends that protein should make up about 30% of a person's diet but the National Health and Medical Research Council recommends "an upper level of 25%", according to the article.

"Why the clear discrepancy between what the CSIRO's researchers were telling it privately and its advice to the public?" Russell asked.

"Had any new evidence emerged to alter the opinions of its researchers?

"Certainly the board and CEO documents don't mention any new research containing contrary findings."