[krrrh]

Regular consumption of nicotine also reduces Alzheimer's risk (and probably Parkinson's). This has been known for a long time. Few things are absolute.

1991: https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC1670208/

> The risk of Alzheimer's disease decreased with increasing daily number of cigarettes smoked before onset of disease (relative risk 0.3 in those smoking greater than 21/day v 1 in non-smokers). In six families in which the disease was apparently inherited as an autosomal dominant disorder, the mean age of onset was 4.17 years later in smoking patients than in non-smoking patients from the same family (p = 0.03).

There is also ongoing research on this topic funded by the US government.

https://www.alzheimers.gov/clinical-trials/memory-improvemen...

[kortex]

Nit: that study is cigarettes. There is more to tobacco than nicotine, such as harmala alkaloids and miscellaneous MAOIs.

Either way, that's super interesting.