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E-Cigarettes: What the Research Shows

What’s in E-Cigarettes?

The nicotine in e-cigarettes goes to your brain quickly. It can cause a brief feeling of relaxation and can lift your mood. As the nicotine leaves your system, your body craves another cigarette. Some research links nicotine to a higher risk of heart disease.  

While the amount of nicotine in e-cigarettes is far lower than in regular cigarettes, the doses can vary greatly by e-cig brand.

The other main chemicals in e-cigarettes are propylene glycol and vegetable glycerin. They are used either separately or together as liquids to make the vapor.

Propylene glycol is a food additive and an ingredient in the fog machines used in clubs and theater shows. It has been through a lot of testing, and the FDA considers it safe for use in food and medicine. It's an ingredient in many food flavorings, toothpastes, and cough syrups. It has been linked to minor skin and lung irritation.

The FDA also considers vegetable glycerin safe for people to use, but there's not a lot of research to confirm its effects on health.  

There’s also a lack of research into what's produced when you "light up." The heat can create potentially harmful chemicals, although in amounts 9 to 450 times lower than in real cigarettes. The evidence isn't clear on the health effects of these lower amounts of chemicals.

Also worrisome is the rainbow of flavors added to make e-cigarettes taste like everything from mint to bubblegum. Although the FDA says these additives are safe enough to be eaten in food, "we don't have enough data showing the potential risk from inhaling these flavors," says Maciej Goniewicz, PhD, PharmD. He's an assistant professor at Roswell Park Cancer Institute in Buffalo, N.Y.

The sheer number of e-cig varieties on the market adds to the problem. "There are different models, different types, different brands," Goniewicz says. 

The chemicals in them can vary, too. That makes it hard to draw any conclusions about their safety.

Secondhand Vaping

Smoking doesn't affect just the people who light up. Everyone around you also breathes in chemicals released in the smoke. Secondhand cigarette smoke has been linked to cancer, heart disease, and many other conditions. So researchers want to know whether secondhand vaping is dangerous, too.

Goniewicz and his research team have measured the amount of chemicals in e-cigarette vapors. They found nicotine in the vapor, but levels of other toxic chemicals were too low to cause concern.

But he says more research is needed to look at the effects of secondhand vapor on people who spend a lot of time with long-term users, especially children. Research is also needed on secondhand e-cigarette vapor outside of the lab, in the real world. "I think there need to be more studies that measure the levels of real settings like restaurants and bars where people would really be using them," Siegel says.

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