Faulty logic

“Associated with!”

Just because using a nutrition intervention is associated with people getting better or worse, doesn’t mean that it was the nutrition intervention that made them better or worse.

Sometimes researchers find an association between something people do – like going to the doctor – and something that happens to them – like being sick. This does not mean that what they did caused what happened to them. For example, it is more likely that people went to the doctor because they were sick than that going to the doctor caused them to be sick.

When there is a link between people using a food, drink, diet or nutrition supplement and getting sick or staying healthy, the nutrition intervention may or may not be the cause. The link may have happened by chance, or people might be getting sick or staying healthy because of something else.

For example, in some countries ice-cream sales and drowning are linked. When more ice-cream is sold, more people drown. That does not mean that eating ice-cream causes people to drown. A more likely explanation is that people eat more ice-cream when it is hot, and they also swim more when it is hot. So telling people to stop eating ice-cream (an intervention) is very unlikely to reduce the number of people drowning!

BEWARE of claims that a food, drink, diet or nutrition supplement has an effect because using it is associated with people getting better or worse.

REMEMBER: Think about whether you can be sure that there aren’t other reasons for the association.