I think it helps. I've read a lot of things about how smoking raises cortisol, and it was on this forum where someone mentioned that it lowers estrogen.
Estrogen is one of the things that affects my migraines, and my cortisol levels were apparently part of my mood swings. I was in a constant state of fight of flight, would get angry to the point of shaking over the slightest little thing, really for most of my life, and it wasn't until I was diagnosed with adrenal fatigue that someone made the connection to childhood abuse and adrenal burnout. Your cortisol and adrenaline levels get all screwed up and I was getting adrenaline surges, hence the shaking and mood swings.
I started taking hydrocortisone and the mood swings lessened considerably. Every cigarette I had smoked over the years before I quit was giving me a dose of cortisol all day long, soothing my nerves, and I didn't even know it all those years, so when I tried to get healthy I screwed myself up. My headaches got worse because of the estrogen surge, and my moods were all over the place because of the drop in cortisol.
I had no clue about this until I joined a thyroid and adrenal fatigue support group and someone else clued me in. I honestly thought everybody got the shakes when they got mad or needed to eat until I was in my 30s and learned it was just me.
Others in my group tell similar stories, so it kind of makes me mad that doctors don't realize this happens, but I guess they don't want to do anything to encourage smoking. Plus they tend to discount anything women say about our health anyway.
With the e-cigs it seems to me I'm getting the same effects I got from regular cigarettes. I never got that from the gum. I could be in the honeymoon-placebo stage here, but I hope not.