It’s been such a mixed week for e-cigs, with one study showing e-cigs are more successful than nicotine patches and gum for helping people quit, yet the American Lung Association ripping the FDA as a “failure” for doing nothing to stem the tide of teen vaping.

Well, this week another study came out that e-cigarettes, while perhaps safer than cigarettes, are still not completely harmless.

In what is admittadly a pretty limited study, a new survey by the American Stroke Association shows that e-cig use is associated with a higher risk of strokes and heart attacks.

From an NPR story:

“There’s a certain notion that e-cigarettes are harmless,” says Dr. Paul Ndunda, the study’s author and an assistant professor at the School of Medicine at the University of Kansas in Wichita. “But this study and previous other studies show that while they’re less harmful than normal cigarettes, their use still comes with risks.”

This study relied on a behavioral factor survey from the CDC and looked at 66,000 e-cig users. It found a 71 percent higher risk of stroke, 59 percent higher risk of heart attack and 40 percent higher risk of heart disease.

(OK, I’m going to be honest here … while I’m sure these figures are accurate, my first question is how many of these e-cig users are smokers and former smokers … the increased risk of stroke and heart disease could be from the smoking more than the e-cigs.)

The study does get into this to a degree, to be fair.

From NPR:

Ndunda found e-cigarette users are twice as likely to also smoke conventional cigarettes, compared with people who don’t use e-cigarettes.

To see the health effects of e-cigarette use alone, Ndunda and his colleague Dr. Tabitha Muutu compared people who had only used e-cigarettes — not conventional cigarettes — to nonsmokers.

“Even in that group there was a 29 percent higher risk of stroke and a 25 percent higher risk of heart attack,” Ndunda says. Taken together, these two analyses point to an additive effect of e-cigarette and conventional cigarette use.

So, Ndunda admits in the aritlce that the study has its limitations because there’s so many factors at play here — e-cigs, mixing e-cigs and cigarettes, and my point, the pre-existing damage experienced by former smokers from their decades of cigarette use.

Anyway, this survey strongly suggests it’s probably a really, really bad idea to mix e-cigs and cigarettes together. That if you’re going to use e-cigs, you really have to quit cigarettes to actually have any health benefit.