Last week’s New Scientist editorial focused on the food crisis currently killing people in countries that most of us have to look up on Google earth. They drew attention to the role of increasing global meat consumption and quickly dismissed the option of eating less meaty diets as unlikely. Why the quick dismissal? Imagine the mirth when people suggested curbing smoking. The parallels between the two issues are striking and deeper than many people realise.
If you haven’t seen the 1940s advertising campaign “more doctors smoke camels” then you may not appreciate that our medical fraternity, as well as the whole of Government, used to be in the pockets of the tobacco companies. That nexus has been broken and Australia has reduced the male smoking rate from 58% in 1964 to 25% in 2001. Females had a brief smoking flurry, but they are now down to 21%.
The situation with regard to meat is pretty much like it was back in 1964 when the US Surgeon General issued his damning report on smoking. Last year’s World Cancer Research Foundation report is the modern equivalent. Its 150+ scientific authors summed up the case on red meat with absolute clarity (p.116):
The evidence that red meats and processed meats are a cause of colorectal [bowel] cancer is convincing.
The issue is a little more complex than tobacco, because WCRF made a clear distinction between chicken which doesn’t appear to cause cancer, and all the red meats (which include pig meat) and processed meats, which do. The major culprits are chemicals called NOCs (N-nitroso compounds). These are made by your body when you digest red meat. These are also found in tobacco smoke and the exposure levels to these chemicals in your bowel is similar to the exposure levels to the chemicals in smokers.
In essence, eating red meat is like smoking cigarettes through your an-s. I told you the parallels were deep!
The Cancer Council of Victoria’s Professor Graham Giles has estimated (on the assumption of causality, as clearly indicated in the WCRF report) that if Australians limited their intake of red meat to 1 serve per week, we would have 6,000 fewer cases of bowel cancer annually. That’s 16 people each day getting bowel cancer from red meat. About 5 of these will arrive at emergency departments with blocked or ruptured bowels.
But the nexus between Australian health professionals and the meat industry is long and strong, just like it was with tobacco. I wrote on the issue in the April edition of The Monthly magazine and exposed how the CSIRO Board had been informed by its staff that high red meat diets caused cancer, but went ahead with a new version of its high red meat diet anyway.
The Dietitians Association of Australia (DAA) is also involved. It is an organisation representing dietitians but accepting funding from Meat and Livestock Australia — among others.
The DAA website has a section on diet and nutrition which contains the following introduction to its report on the WCRF report.
A recent review by the World Cancer Research Fund (WCRF) of the evidence around cancer and lifestyle factors showed that there is an inconsistent and relatively modest link between high intakes of meat, particularly processed meats, and the risk of colorectal cancer.
Note the language: “an inconsistent and modest link”.
Language is absolutely crucial to scientists, especially epidemiologists. They almost always talk about “links” and “associations” because they are drilled right through their training that correlation doesn’t prove causation. People who carry cigarette lighters get more lung cancer than people who don’t, but cigarette lighters don’t cause lung cancer. Establishing causality turns out to be usually really tough. So when epidemiologists say, like the WCRF did, that red and processed meats CAUSE cancer, you know they are deadly serious and extremely sure. This isn’t a word game.
Whoever wrote the DAA website line either hasn’t read the report or is being deliberately misleading.
If you think 6,000 cases per year for people eating more than 1 serve of red meat per week is a “modest link”, then you haven’t watched a person die with bowel cancer.
This brings us back to New Scientist and that food crisis. How hard would it be to reduce meat consumption (particularly red and processed meat) if we had a nutrition and medical establishment that told the public the truth and didn’t misrepresent the state of research?
The 542-page WCRF report is freely available here.
Apparently the energy in: energy out ratio of growing beef cattle vs growing chickens is 30:1 vs about 3:1, also. Not to mention the greenhouse gas effect of methane from all the farting the beef cattle do… Methane has a 60 times greater ‘global warming potential’ (GWP) than CO2 over the first 20 years of its presence…
As a medical practitioner who has no links with the meat industry or the Dieticians Association of Australia(and in fact consumes less than one serve of red meat per week) I thought this article was pushing the limits of both science and logic.
Although the WCRF report is interesting reading and certainly adds to the body of evidence suggesting that excess red meat consumption is linked with an increased incidence of colorectal cancer. However, they themselves note the degree of variation in the studies they based the recommendation on, with only four studies showing a statistically significant increase in relative risk.
Even accepting the probability of an increase in risk, they are much more cautious with defining the magnitude of the risk. I would be fascinated to see how Professor Giles calculated the figure Mr Russell has given of “6,000 fewer cases of bowel cancer annually”. In 1999 there were 11637 new cases of colorectal cancer in Australia (Australian Institutes of Health and Welfare data). On my reading of the WCRF report (they estimate relative risk of 1.43 per times/week) I don’t see how this equates to a halving of the total number of cases – more like a reduction of 1500-3000, depending on which figures you go on. While this is substantial, it is not conclusive and it is certainly far, far less than the relative risk increase that smoking has with lung cancer (which Hammond and Dorn calculated in 1966 to be 10.73). To equate the links between smoking and lung cancer with the links between red meat and colorectal cancer is to misunderstand the data.
Perhaps a more responsible way of reporting this would be to state that the report shows a small but (in their opinion) significant increase in the risk of colorectal cancer which appears to be dose dependent (although this is less certain) and apply to individuals who eat greater than 500g/week. Although this doesn’t really fit in with the ‘meat industry conspiracy’ argument that Mr Russell appears to be using this report to try and advance, it’s more accurate.
The WCRF report is recent report that is itself cautious in its conclusions and recommendations. You can’t blame dieticians and doctors for not shouting from the rooftops. It takes time to change our perceptions of how our behaviour influences our heath, even when the case is far more compelling that this one is. To accuse the DAA of being deliberately misleading is itslef misleading and smacks of paranoia. In fact, most dieticians would certainly agree with the conclusions of the report to limit intake of red meat (not a new idea at all), as well the intake of alcohol and saturated fats while increasing the intake of fruit, vegetables, cereals and most of all do more exercise.
Now that’s a message that the evidence can support!
“If you think 6,000 cases per year for people eating more than 1 serve of red meat per week is a “modest link”,
Actually I do think so;out of a population of 21 000 000 you would be hard pressed to find many non-vegetarians who eat only one serve of red meat per week.
A gross misuse of statistics.
Yes, and the meat industry is bad for the animals and the environment as well. In fact any way you look at the meat industry it comes up looking bad. Some readers may have seen the TV program Animal Pharm which showed the genetic engineering now being utilised in agriculture research to precisely enable meat production to be increased so that more people can eat more meat. Not a nice world we live in I’m afraid.
Why do you publish such obnoxious garbage? We have evolved to eat red meat over millions of years. Get used to the idea – it is here to stay.