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!