Chocolate has the Mars Company and other Big Sugar companies behind it pushing for justifying chocolate as a "health food" in the public mind. It is very obvious that they are wiling to distort the truth for better sales; people who can ease their conscious about eating unhealthy sweets buy more chocolate[0]. There might be some real effect to eating raw cocoa, but that does not really translate to your average chocolate bar with insane amounts of fat and sugar.
Tea/Coffee is kind of similar, as would be the "drink x glasses of water per day"-advice, which is a distortion of science by bottled water companies (fruits, vegetables and other food contains a ton of water already).
For this reason I also don't buy that salt is safe: there are very strong vested interests in the food industry that want salt to be (considered) safe to sell more food, whereas I cannot see a comparable bias on the "eat less salt"-side.
For this research the situation seems to be have some of the mentioned problems, but not to the same degree:
On the one hand, that tumeric has an in-vitro effect is pretty well established. The issue is that the normal form we put on our food is probably not absorbed in a dosage that has a significant effect. However, this was a trial with a bio-available form, in a high enough dosage, so that obvious flaw is out of the picture.
On the other hand, that bio-available form is a product, so the company behind it wants it to be effective. Still, Big Pharma is under more scrutiny than Big Sugar, so I have cautious hopes this might actually work out in the end (and it won't be sold in the form of calorie-rich sweets at least).
Admittedly, I'm biased here: my grandmother on my mother's side, and my grandfather on my father's side both had Alzheimers (or something very similar to it at least). My parents are now their late sixties, I would really like to see them stay healthy and happy for a few more decades.
[0] https://www.vox.com/science-and-health/2017/10/18/15995478/c...
Another argument in favour of eating potassium and less sodium, which is pretty well established:
https://nutritionfacts.org/video/lowering-our-sodium-to-pota...