Katherine Heigl Smoke Sticks: Are They Bad For You?

(CBS) Actress Katherine Heigl, 31, best known for her role on "Grey's Anatomy," broke out her electric "smoke stick" Monday night while appearing the "Late Show."

She told David Letterman she's tried everything to quit smoking, and this is her latest effort.

A smoke stick is a cigarette substitute that heats the liquid nicotine inside with a small battery-powered atomizer.

Are smoke sticks, a.k.a. electronic cigarettes, as bad for you as cigarettes?

The jury is out.

Dr. Alan Blum, who directs the University of Alabama Center for the Study of Tobacco and Society, tells CBS News there is a lot to debate.

In principal, says Blum, smoke sticks are less harmful, because they deliver "just a little bit" of vaporized nicotine without the harmful combustion by-products one gets from a real cigarette.

In addition, there is little second hand smoke to worry about.

But smoke sticks are poorly regulated, and the FDA is working to reign them in. Recently, the agency sent warning letters to five electronic cigarette distributors for making unsubstantiated claims and for having poor manufacturing practices.

Heigl, who started smoking in her early 20's, is trying to be as healthy as possible now that she is a mom (she adopted a girl from South Korea last year). She's tried nicotine gum and patches  and the prescription medication Chantix, according to the New York Daily News.

Smoke sticks seem to be the only thing that works for her. 

Forty-six million Americans smoke, and smoking-related illnesses kill 1,000 of us each day.