## an increase of 18% a day?!

A striking figure I saw earlier this week in a newspaper and confirmed by checking on the World Health Organisation (WHO) today:

…if the association of red meat and colorectal cancer were proven to be causal, data from the same studies suggest that the risk of colorectal cancer could increase by 17% for every 100 gram portion of red meat eaten daily…

The way I interpret this sentence and the every in it when I read it is that each time I eat a portion of 100g of red meat, my probability of getting a cancer increases by 17%. Actually the previous sentence in the report sounds even more dire:

An analysis of data from 10 studies estimated that every 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by about 18%.

Which means that eating a sausage a day would multiply the probability by about… 10²³! This cannot be: turning statistics into “plain” language  can be so confusing! Or else pardon my French!!!

### 2 Responses to “an increase of 18% a day?!”

1. No, it cannot be. These are comparisons of risk by daily intake.

Per 50g difference in daily processed meat intake, there’s an 18% higher lifetime risk of colorectal cancer.

Or, later in the WHO Q&A, per 100g difference in daily red meat intake, there’s a 17% higher lifetime risk of colorectal cancer.

The WHO Q&A is quite clear about the intakes being “daily”, i.e. you’d need to eat 50g/100g extra processed/red meat per day to have the extra risk.

Even if one wants to quibble about whether these log-linear relationships hold at all levels of intake, the associations make sense as population averages.

• I am simply reflecting on my understanding of the sentence when I read it! I understand the 18% risk is meant to be associated with an extra daily dose of meat for one’s entire life, but to my French eyes it reads differently!!!

This site uses Akismet to reduce spam. Learn how your comment data is processed.