I remember when i was younger i got told that i could start eating normal food at age 12 cause my brain was fully developed. So thats what i did, it was great eating those first time Hamburgers etc from McDonalds etc. It was only when i was 17-18 years old that i knew something was'nt right, i started having panic attacks, was very anxious and depressed and i hated the way i was thinking, i always thought the worse of something, i was only young had everything in life and i never understood what i had to be so sad about, intill i met my New doctor and dietician they put be straight on a low protein diet and after a few month of a very strict diet, i was a totally different person, depression dissapeared the panic attacks gone, and i was my own cheerful confident person. Although i ain't saying its the same with everyone but there's loads of other syptoms that high levels do that we don't notice.
High levels can make:
Hard to Concentrate
Moodiness and Aggressive
Tremors, twitches in eyes
aching Bones or Joints etc
Your Husband may not have any of these syptoms, but by returning to the low protein diet will make him alot healthy, more energetic etc
My doctor always told me in an easier form that i could understand was that now our brains are fully developed eating Protein or PHE is like Poison to our brain, and it can affect us all Emotionally (more for women) Neurologically, mentally, and phsycology (sorry about spelling).