The serious bit
The WHO data is split into men and women. I first did the scatter diagrams for average (mean) cholesterol levels and CVD deaths. Then I ran the Pearson correlation coefficient on these numbers. This gives us the term called “r”. “r” tells us if there is some kind of a relationship: an r score of 0 would indicate no relationship; an r score of 1 would indicate a perfect relationship. A negative r score is called an inverse relationship e.g. the price of concert tickets is likely to be inversely related to the number of concert tickets bought – fewer tickets being bought at higher prices.
The “r” score for men revealed that there was a small relationship of 0.13 – however this relationship was inverse. The diagram and correlation shows that higher cholesterol levels are associated with lower CVD deaths and lower cholesterol levels are associated with higher CVD deaths. In women, the relationship is stronger – to the point of being meaningful. The r score was 0.52 – but, again, inverse. For women, higher cholesterol levels are quite significantly associated with lower CVD deaths and lower cholesterol levels are quite significantly associated with higher CVD deaths. Please note that I have added r squared on the graphs below (excel can do this for us) and it can confirm that you’ve got your r numbers right and r squared tells us the strength of any relationship we have observed.
All you need to do is to look at the lines going down to the right and wonder how on earth we ever got away with telling people that cholesterol causes heart disease. High cholesterol is associated with lower heart disease and vice versa – for all the data available in the world. High cholesterol is not even associated with high heart disease, let alone does it cause it.
Click the link and read this article. The charts show the higher the cholesterol, the lower heart disease is and the lower cholesterol, the higher heart disease goes.
Worth the read.