Tuesday, 20 October 2009

Unknown unknowns...

They laughed at Donald Rumsfeld when he came out with his quote - “There are known knowns. There are things we know that we know. There are known unknowns. That is to say, there are things that we now know we don’t know. But there are also unknown unknowns. These are things we do not know we don’t know.”

I am not a fan of his for a number of reasons but this was wiser that we gave credit for at the time. I was reminded of it by the
Annual Report of the Chief Scientist of the Food Standards Agency (FSA) who quotes it in relation to food safety. The FSA was set up in the wake of the BSE crisis to restore consumer trust in the safety of the UK food supply. BSE was an unknown unknown. Until the 1980s we didn’t know about it and also didn’t know that we needed to know about it.

Organisations like the FSA and charities like ours involved in medical research do what is called “horizon scanning”. Is there anything out there which could be a risk but which we haven’t thought of yet? In breast cancer we are identifying risk factors which no one knew were risk factors – what we do about them is another matter – but “knowing” takes us a step closer to beating breast cancer.

This also came to mind as a colleague is pregnant. When I had my children some time ago there was little advice on diet. What we “knew” then was based on very little evidence, my suspicion is that it may have swung too far over the other way – but that’s my personal opinion and not an informed one.

I was told that spina bifida was caused by potato blight (it isn’t, we now know that you can reduce the incidence by taking folic acid) so avoided potatoes for the pregnancy. I was also told to eat liver at least once a week (no – no – too much vitamin A) and didn’t drink because it made me feel nauseous (as did coffee and tea) rather than because it wasn’t good for the baby. Shellfish, soft cheese, uncooked eggs – none of these were considered a problem. On the other hand we accepted a higher rate of miscarriage and also, if you couldn’t become pregnant it was a misfortune but there was nothing that could be done.

I wonder what unknown unknowns are still out there lurking.......

Read Andrew Wadge, Chief Scientist FSA, blog

No comments:

Post a Comment