Reacción a "A protein in the blood of older women is associated with an increased risk of cognitive decline and dementia"

The headline of this press release is misleading, in my view.

The blood test does not ‘predict’ dementia early as one would commonly understand it; if you get a result above a certain level, it does not tell you if you are, or not, going to develop dementia with any degree of accuracy.

We know that there are changes in the brain for decades prior to the appearance of visible dementia symptoms, and one of those changes is the build-up of the molecule pTau217. The researchers in this study have measured the levels of pTau217 in the blood of a large number of women and then tracked them for an average of 15 years (longest 25 years) to see who developed either dementia or a condition called mild cognitive impairment.

They show that if you have substantially above-average levels of pTau217 then you are more likely to develop dementia than someone with lower levels. It does not predict that you will get dementia. This increase in risk is probably slightly higher than the dementia risk associated with smoking or heavy alcohol consumption and this probably reflects these early pre-symptomatic changes in the brain.

This is useful information – although it is not a prediction of a future dementia diagnosis, it would give an individual the opportunity to manage risk factors under their control, for example give up smoking and drinking alcohol, exercise, and maintain a healthy weight.