Remember, that as per UN mandate for the last decade, table salt in Mexico is "fortified" with sodium Flouride. While it is obviously not enough to totally zombify the populous, it can be avoided.
3 or 4 years ago, while still living in central Mexico, my mind was slowly but obviously going. I was losing the most basic memory and it was embarrasing not remembering names of people close to me.
That was when I eliminated Flouride from my salt and toothpaste, and started taking 50 to 200 mg of potassium iodide per day, and all that turned around, I got my memory back, and in fact greater mental acuity than perhaps I have had most of my adult life.
While you are in Mexico City, at a major Farmacia or Botica, such as Farmacia Paris on El Salvador near the presidencia, you may purchase, pure lab-grade Sodium Chloride (Cloruro de Sodio), and pure lab grade Potassium Iodide (Yoduro de Potasio)
Best Wishes, God Bless You, Take Care
My response: I guess there must have been a religious exemption, because at a few of the upper class stores you can buy KOSHER NON FLUORIDATED SALT. And that is what I get. I did notice that the fluoridated salt kicks in the stupid factor really quick. I wondered how bad it was and tried it, and noticed a huge drop in brainpower within only a few meals. Hard to believe, but true, the salt in Mexico has got to be spiked really hard. Anyway, I have found the good stuff.