There are societies that drink a lot of alcohol and live long lives by following local "rules" about drinking. People in those societies live long lives.

So I disagree.

A good way to test it - do it yourself. You will see a noticeable difference. Go in the evening after the gym. Hydrate yourself through the day and you will see a huge difference in performance.

There is quite a lot of talk about it in sports/gym circles for many years.