Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

People who get yearly flu vaccines probably go to the doctor more regularly than those who do not. I would expect that people who more regularly go to the doctor are also more concerned about their health. I'd expect people who are concerned with their health to behave in ways that limit disease.

Without a proposed method of action, I suspect this is just noise.

The researchers controlled for "number of routine well visits during the look-back period, and total number of health care encounters during the look-back period (as a proxy for overall healthcare utilization rate)" [1].

[1] https://content.iospress.com/articles/journal-of-alzheimers-...

Otoh, people who visit the doctor regularly are more likely to be diagnosed

Even simpler. Annual flu shots require a decent degree of executive functioning. People with early stage neurological decline are less likely to make or keep their appointment

There’s a section in https://content.iospress.com/articles/journal-of-alzheimers-... called Hypothesized Mechanism(s), which contains (amongst supporting details) the following:

> 1) influenza-specific mechanisms, including mitigation of damage secondary to influenza infection and/or epitopic similarity between influenza proteins and AD pathology; 2) non–influenza-specific training of the innate immune system; and 3) non–influenza-specific changes in adaptive immunity via lymphocyte-mediated cross-reactivity.

Thank you for the link. That's a interesting population, older people who regularly receive medical care but refuse flu vaccines. I wonder if that is representative of the general population.

That was obviously controlled-for.

A study of this size would not be conducted by idiots. HN has no such filter, though.

You should look at home many papers get withdrawn over really simple stuff.