Being positive and happy is healthy for you. Obviously it improves your healthspan but it also has positive effects on your mitochondria.
Maybe we can do our own RCT based on how many likes we give each others posts? It always has a positive effect on my mood getting a little 
on my posts… 
Reference video (44:00)
Thank you for posting this video! I found it fascinating. Especially the Psycho Mitochondrial links.
Stress and Mitochondria the negative feedback loop.
I think what happens is that when glucose levels are higher more ROS are generated. This does harm to the mitochondria and particularly mitochondrial DNA. Higher cortisol levels tend to keep serum glucose levels high.
I agree. Its so easy to misinterpret this sort of information. If a study was done on mitochondrial damage and ROS during exercise, I’m sure they’d find about the horrors of exercise. Yet less exercise is even worse. Why?
The body adapts to stress from whatever source. So it’s not the stress that is the problem, it’s the lack of adaptation which comes from too little recovery. Cycles of stress is the key.
Cortisol is good for waking up and getting the body functions moving in “awake” program. Low cortisol in the morning feels terrible.
High blood sugar is good to run to catch dinner but all the time is destructive.
ROS tells the body to adapt. Too much for too long causes damage to mitochondria and more.
For me, progressive adaptation is my focus. More and more exercise that I can handle. Yet being sympathetically activated for too much of the time is destructive. So I also work on methods for turning off (emphasizing parasympathetic ANS). I emphasize non chemical methods here so I learn life skills.
Rumination can decrease brain size too…
Martin Picard has some more interesting content…
I really need tFUS