Study: Same Nicotine Levels, but lower carcinogens exposure in e-cigs

e-cigarettes first reported on vaping and e-cigarettes in late July. We then quoted The Mash, a publication distributed to Chicagoland schools, which declared that “research from institutions like the Roswell Park Cancer Institute (RPCI) suggests that [it] may be true” that, as some users of e-cigs believe, “vaping is a safer alternative to smoking that [using] traditional cigarettes.”

Now, RPCI researchers have declared that, for e-cig users, “nicotine exposure remains the same, while exposure to specific carcinogens and toxicants is reduced,” among smokers who switch from tobacco cigarettes to electronic cigarettes. Their new research was published online ahead of print in the journal Nicotine Tobacco Research.

“To our knowledge, this is the first study with smokers to demonstrate that substituting tobacco cigarettes with electronic cigarettes may reduce exposure to numerous toxicants and carcinogens present in tobacco cigarettes,” says lead author Maciej Goniewicz, PhD, PharmD, Assistant Professor of Oncology in the Department of Health Behavior at Roswell Park. “This study suggests that smokers who completely switch to e-cigarettes and stop smoking tobacco cigarettes may significantly reduce their exposure to many cancer-causing chemicals.”

In a study conducted between March and June 2011, 20 healthy adult daily smokers were provided with electronic cigarettes and 20 tobacco-flavored cartridges. Participants in the study had smoked traditional cigarettes for an average of 12 years, and 95% of them said they planned to quit smoking. All participants were asked to substitute their usual tobacco cigarettes with e-cigarettes for two weeks.

The international scientific team measured participants’ urine levels of seven nicotine metabolites and 17 biomarkers of exposure to carcinogens and toxicants present in cigarette smoke over a two-week period. The biomarkers measured in the study are indicators of the risk of several diseases, including lung cancer. For 12 of 17 measured biomarkers, they found significant declines in exposure to toxicants when participants changed from tobacco cigarettes to e-cigarettes. The decline in toxicant levels was similar to the decline seen among tobacco users who quit smoking. Nicotine metabolites remained unchanged among the majority of study participants, confirming findings from earlier laboratory studies showing that e-cigarettes effectively deliver nicotine to the blood.

“Our findings suggest that e-cigarette use may effectively reduce exposure to toxic and carcinogenic substances among smokers who completely switch to these products,” says co-author Neal Benowitz, MD, Professor of Medicine at the University of California, San Francisco. “Future research will help determine whether e-cigarettes reduce the risk of disease among dual users — those who both smoke and vape — and those who use electronic cigarettes for a long time.”

The study, “Exposure to nicotine and selected toxicants in cigarette smokers who switched to electronic cigarettes: a longitudinal within-subjects observational study,” is available at

This work was supported by the Ministry of Science and Higher Education of Poland (grant no. NN404025638) and the U.S. National Institutes of Health (award nos. P30DA012393, National Institute on Drug Abuse, and S10RR026437, National Center for Research Resources). Dr. Goniewicz received a research grant from Pfizer, a pharmaceutical company that markets smoking-cessation medications. He and Benowitz have been consultants to pharmaceutical companies that market smoking cessation medications, and Dr. Benowitz has been an expert witness in litigation against tobacco companies.


Cancer a ‘Modern’ Disease? Hardly: 2 Million Year Old Version Is Found



A specimen of a 1.7 million year old cancer

Paleopathologists in South Africa have found two million-year-old evidence of cancer, long thought to be a modern, lifestyle-related disease. Separately, a 1.7 million-year-old example was found in another South African location. These oldest-by-far cancerous specimens were evaluated using advanced 3D imaging methods as diagnostic aids at the University of the Witwatersrand (Wits) in Johannesburg, South Africa. The researchers included Edward Odes, a doctoral candidate at Wits, and Patrick Randolph-Quinney, also of Wits and of Cambridge University in England. Randolph-Quinney was identified as the lead researcher in the paper published on July 28 in the South African Journal of Science.

“Modern medicine tends to assume that cancers and tumors in humans are diseases caused by modern lifestyles and environments,” Odes said. “Our studies show the origins of these diseases occurred in our ancient relatives millions of years before modern industrial societies existed.”

First, a 1.7-million-year-old foot bone with cancer was found at the Swartkrans cave in South Africa. The exact species is unknown, but it is a hominin, or bipedal human relative, the researchers said.

Scientists also found a benign tumor in the 2-million-year-old vertebrae of an Australopithecus sedibachild found in South Africa’s Malapa cave.

Until now, the oldest hominin tumor had been found in the 120,000-year-old rib of a Neanderthal, according to the researchers.

The cancer in the foot was an aggressive type called osteosarcoma, they said.

“Due to its preservation, we don’t know whether the single cancerous foot bone belongs to an adult or child, nor whether the cancer caused the death of this individual, but we can tell this would have affected the individual’s ability to walk or run,” said Bernhard Zipfel, in a Wits news release.

Zipfel, a scientist who is an expert on the foot and locomotion of early humans, added, “In short, it would have been painful.”

Another member of the research team noted that the benign back tumor was a first in several ways.

“The presence of a benign tumor in Australopithecus sediba is fascinating not only because it is found in the back, an extremely rare place for such a disease to manifest in modern humans, but also because it is found in a child,” said Randolph-Quinney, in the news release.

“This, in fact, is the first evidence of such a disease in a young individual,” he explained. Randolph-Quinney was lead author of the benign tumor paper and co-author of a separate cancer paper published at the same time, in the same journal, as the benign tumor one.

More information on this topic is available here.