A repeated theme in the Renewed Man program -- in fact, one of the 12 keys we focus on -- is that there's a deep connection between our emotional / mental health and what we eat. Seratonin is known as the "feel-good" neurotransmitter. It contributes to positive emotions, well-being, and happiness.
If anything, Brian Johnson is giving a low estimate here -- recent research shows that as much as 95% of serotonin is produced in the gut, and only 5% in the brain. What we eat affects how we feel, and how we live.
