Tuesday, June 11, 2013

New Study Shows that Electronic Cigarette Vapor is Much Less Cytotoxic than Cigarette Smoke

A new study from researchers in Italy and Greece, under the direction of senior author Dr. Konstantinos Farsalinos, reported last week in the journal Inhalation Toxicology that vapor from electronic cigarettes was found to be much less cytotoxic (damaging to cells) than tobacco smoke.

(See: Romagna G, Allifranchini E, Bocchieto E, Todeschi S, Esposito M, Farsalinos KE. Cytotoxicity evaluation of electronic cigarette vapor extract on cultured mammalian fibroblasts (ClearStream-LIFE): Comparison with tobacco cigarette smoke extract. Inhalation Toxicology 2013; 25(6):354-361.)

The study examined the effect of electronic cigarette vapor from 21 different brands compared to cigarette smoke on the growth of fibroblasts in cell culture. This is a laboratory test that detects whether or not a substance causes cell damage and therefore inhibits cell growth.

At the highest dilution, 20 of the 21 brands of electronic cigarette showed no signs of cytotoxicity. One brand showed evidence of cytotoxicity at the highest dilution but not at any lower dilutions. Even at this high dilution, the cytotoxicity was more than two orders of magnitude lower than that of cigarette smoke. In contrast, cigarette smoke was cytotoxic up until the third level of dilution.

The study reports the findings as follows:

"The main result of our study is that the vapor from only 1 of the 21 EC [electronic cigarette] liquids examined had cytotoxic effects on cultured fibroblasts according to protocol definition. CS [cigarette smoke] extract had significant cytotoxic effects, and fibroblast viability was significantly lower at all extract concentrations compared to EC vapor extracts."

The study concludes:

"This study indicates that EC vapor is significantly less cytotoxic compared to tobacco CS."

The Rest of the Story

This study adds further evidence that electronic cigarette use is much safer than cigarette smoking. There is absolutely no scientific basis for anti-smoking advocates to continue arguing that vaping is simply another form of smoking. This should put that argument to rest. Completely.

The one electronic cigarette brand that did show evidence of cytotoxicity was a "coffee-flavored" brand. Dr. Farsalinos and colleagues point out that it is quite likely that the cytotoxicity resulted from the flavoring, rather than the electronic cigarette liquid components generally used in most brands, as processing of coffee beans has been shown to lead to degradation products that exhibit cytotoxicity. They also point out that even for this brand, "the cytotoxic effect ... was found only at the highest extract concentration, and, even at this concentration, fibroblast viability was 795% higher compared to CS extract."

Nevertheless, the results do suggest that studies are necessary to make sure that flavorings or other additives in electronic cigarette liquids are not harm-producing. This is an area that the FDA could address in its regulatory oversight of these products.

The rest of the story is that we now have additional scientific evidence that vaping is much safer than smoking. We already knew that vaping greatly lowers the carcinogenic risk associated with cigarette smoking. Now we know that vaping greatly lowers cytotoxicity as well. There is strong evidence that vaping lowers both the carcinogenic risk and lung disease risks associated with cigarette smoking.

It is simply untenable for anti-smoking groups and policy makers to continue the argument that vaping is simply another form of smoking. There is a world of difference between the two. And that difference might just be that between life and death for hundreds of thousands of electronic cigarette users.

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