computer algorithms find associations between some types of foods which may be risk factors for dementia. but genes, diabetes, dieting & mental state were all more strongly linked to dementia.  

original article: Samieri et al., 2020 (Neurology), reported in: The Sun by John Sturgis on 22nd April 2020 & The Daily Express by Katrina Turrill on 23rd April 2020 image source

this story was in episode 0 #burgers #sausages #dementia #pizza #yoghurt

the error bar says

The Express informs us that a diet rich in processed meat leads to dementia, and The Sun goes further, specifically blaming beef burgers and sausages, under the headline ALZHEIMBURGERS.

the story is based on a rather speculative paper by Samieri and colleagues in the journal Neurology. As part of a much larger longitudinal study in South West France, they analysed the food that 209 people, who later went on to develop dementia, reported eating in 2001-2002. these people were matched with 418 people who did not later develop dementia.

when originally given the food questionnaire, there were no statistical differences in ANY of the 62 kinds of food and drink between the two groups.

instead, what the paper suggested is that it is the specific combination of foods that is important for dementia. Not the overall amount or types of food eaten, but the combination.

there is a lot of complex data-mining in the paper, but essentially, people who reported eating French charcuterie, and who later went on to get dementia, also tended to report eating potatoes, soup, and yoghurt. yes, yoghurt.

by contrast, the control group who ate just as much charcuterie also tended to eat fresh vegetables and pizza. mmm, pizza.

do burgers and sausages cause dementia?

first, remember there were NO DIFFERENCES AT ALL in the amount of food eaten at baseline. even charcuterie was eaten IDENTICALLY in the two groups.

second, in one of the paper's graphs YOGHURT was showing just as strong relationships to dementia as charcuterie, so why isn't yoghurt making the headlines?

third, in the original questionnaire, no-one was ever asked about the specific combinations of foods that they ate, just how often they ate individual foods.

fourth, the group who went on to develop dementia, a) had significantly higher genetic risk of Alzheimer's, b) were significantly more likely to be diabetic, c) were significantly more likely to report having lost weight recently, and d) had a significantly lower mental state score at baseline.

overall, these are some very complex data-mining and statistical network analyses being used here to illustrate the story. they do not show that burgers cause dementia, just as they do not show that yoghurt or pizza do. or don't. it's very confusing.


this paper presents no evidence that burgers and sausages cause dementia.


The Sun: fudge - scientific story distorted

The Daily Express: fudge - scientific story distorted