Gum disease and Alzheimer’s: Your questions answered

https://www.newscientist.com/article/2192409-gum-disease-and-alzheimers-your-questions-answered/

People are questioning a landmark study suggesting that a bacterium involved in gum disease may also cause Alzheimer’s. Here’s what you need to know about the study

P. gingivalis may be the main culprit in Alzheimer's disease

P. gingivalis may be the main culprit in Alzheimer’s disease

A. DOWSETT, PUBLIC HEALTH ENGLAND/SCIENCE PHOTO LIBRARY

The publication of evidence that gum disease bacteria may cause Alzheimer’s has prompted questions on social media about how seriously we should take the results. Here’s what you need to know about the landmark study.

Does the study show that the bacteria cause Alzheimer’s disease, or just that the two are linked in some way?

Any well-informed reader will know that correlation doesn’t mean causation, and not every link between two factors implies that one causes the other. But …