Perhaps not the same thing, but a few years ago, when I was married to my first wife (...that sounds like I go through them on a regular basis...), I was starting to... get foggy. My thoughts and memory were not as clear as they used to be. I started forgetting things, and couldn't focus like I used to.
This is going to start sounding like one of those info-mercials.
I starting taking something called Ginko Biloba. I got it at the local Vitamin World. I take other vitamins in the morning, so just added a couple of these to the mix of vitamins. Within a few weeks, my mind started clearing up. I know that some may attribute this to just something seasonal or other... but I swear that I felt better when I started taking these pills.
I still take them. I've also noticed that I can recall memories from my past with little effort. I like to make it into a game. I will pose a question like... "What was the name of that man that I worked with at the radio station?" I will ponder on it a bit, then let it go. Later, when I am not thinking about it, the answer will pop into my head... "Artie Bigl...."
It's the weirdest thing.
Anyway. I've had folks ridicule my selection of vitamins. I've had some say that it doesn't make any difference. That it's due to something else. Whatever.
I'm a grown man. If I want to spend my money on something that I feel helps me, I will. My current wife has remarked that she doesn't know how I can remember names of people from so long ago. (We're talking over 30 to 35 years ago.) I don't either. It's weird - but it's also fun.
Oh. And just so you'll know... I've never been good with remembering names. Never.
I hope that you can figure out something that will help your husband. The only reason that I wrote this long (and possibly boring) info-mercial is that you said that you were going to do research on herbs. I am just trying to help.
Regards,
Jim TX