Other considerations:
1. This essay assumes that the reader has already reached the stage in his thinking that concludes that overpopulation is already an enormous problem affecting every aspect of our lives. If not read this.
2. This is a very difficult problem for man to deal with and remain moral. Most suggestions will involve imposition from the political hierarchy onto the population and the killing of humans. This solution involves choice by a knowledgeable populace and no violation of generally accepted moral precepts.
3. This solution will require reorientation of human thinking on some points. The generally accepted notion, true on the individual level, that death is an opponent to be fought, is untrue at the species level. Instead it is best thought of as a tool used to guarantee survival.
4. Isolating the chemical responsible for aging has some dangers. If it could be used to shorten the human life span, the reverse may also be true. However, this option would probably only be practical for small numbers of wealthy individuals. "There is no such thing as a free lunch".
5. A possible benefit of this particular method of dissemination, through cigarettes, is that the medical problems attendant on cigarette use would be largely bypassed. The smoker would die of old age before they have time to develop.