There is some truth to what he says...
I smoked several times a day for several years, and I'm talking the really primo good shit (many of my friends were big time growers in Humboldt and Mendicino). Due to my years of pumping smoke down my lungs (and I have never smoked cigarettes), I now have a chronic cough, I'm pretty sure it caused/contributed to my lowered sperm count, and my immune system is not what it used to be.
One of the great ironies of life, is that when I became an adult webmaster, I found I had to cut WAY back on my pot intake in order to be productive (I do most of the work myself - content shooting, editing, design, marketing, etc). I find it really was a blessing in disguise, as I feel much healthier, and definitely more productive now.
I really don't regret my years of toking. I had some great times. However, times change, and so did I. Don't get me wrong, I still get high from time to time, and I really enjoy it even more every time I do, since I get really wasted easily as a result of not smoking all of the time anymore.
My only recommendation is to use a bong, to filter the harshest part of the smoke. I am convinced that inhaling burning paper of any kind is not healthy.
While I was never into THC pills or cooking my pot, I say now, if you can still get a good buzz, then it is worth pursuing if you are concerned about your longterm health.
Peace...
ADG