Yogurt for long life

I was a child when Americans started eating yogurt.  People used to get their yogurt at the health food store, I think.  I remember an advertisement on TV sometime around 1979 -1981, an ad about yogurt and how the oldest people in the world eat yogurt.  So, yogurt gives long life.  I want a long life; I'll eat a lot of yogurt.  One day recently, I was daydreaming and I had this idea, What If It Wasn't Just the Yogurt?

What if their longevity had to do with living at high elevation?  Less oxygen, less decay, unchanging...  So how tall are those mountains where the oldest people live?  Soviet Georgia in 1980 - maybe it was a very quiet place?  I don't know what held that country together, nor why they had a war recently.  I am thinking about medical mysteries a lot these days.  I am sure the yogurt helped with longevity, anyway.

Maybe the yogurt helped them keep a healthy appendix.  I read a new theory that the appendix  has an important job.  Everybody used to think that the appendix was an unnecessary body part.  Now, the new idea is that the appendix stores healthy gut flora, and helps the good flora repopulate whenever you lose them to illness (right, I did not want to say, lose them to diarrhea.). It is so cool to learn new things about anatomy.  I thought there wasn't anything new to learn about the human body.

I thought that subject was pretty much entirely known.  But this summer there was news of the discovery of lymph nodes/ lymph somethings in the brain.  Ok, I don't know anything about it.  But when I read about the discovery, I went straight away to Wikipedia.  I checked, there was a picture of the lymph system, and it only went up to the neck, not the brain.  All the anatomy textbooks must be revised, how often does that happen?

So, I spent months thinking about lymph nodes (lymph passages?) in the brain.  We know the human brain needs a lot of food, lots of glucose.  But, there has to be waste products from all that food.  How does the waste get cleaned out?  Wish that I knew this subject better.  Anyway, I started checking regularly for news relating to the brain.  Because I Want To Be Okay.  I want to be healthy not crazy.  I can accept that I may have to take antidepressant medication for the rest of my life.  But, I still feel crazed often.  And, I am worried about the children, how to prevent craziness in the next generation?