The present study is the first that examines the level of tobacco toxins in the bodies of smokers of Chinese herbal cigarettes. We examined the major metabolites of nicotine and two groups of tobacco carcinogens among smokers of herbal cigarettes. There was no detectable difference in levels of nicotine or total NNAL, the metabolite of the main tobacco specific carcinogen NNK, or PAHs between herbal cigarette smokers and regular cigarette smokers.
Smokers of herbal cigarettes had lower concentrations of unadjusted cotinine and trans-3′-hydroxycotinine in the urine, but not after normalizing for creatinine. This result may suggest slightly lower intake of nicotine from their cigarettes, or more concentrated urine among herbal cigarette smokers. The reason for lower nicotine is unclear, as we did not measure the nicotine content of the various types of cigarettes. The primary toxicity of nicotine is sustaining addiction, and it is doubtful that very small differences in nicotine exposure, as were seen in our study, would have any meaningful effect on the addiction potential of the cigarettes. In any event, measures for tobacco smoke carcinogen biomarkers demonstrate no evidence whatsoever of lower exposure in herbal cigarette smokers, suggesting no less cancer risk.
While our results show that herbal cigarette smokers have similar levels of carcinogens in their bodies as regular cigarette smokers, we could not test the industry claim that the herbal additives inhibit the toxicity of these carcinogens. We could not locate any published studies that examined or supported such claims.
We found significant correlations between total NNAL/total PAHs and the metabolites of nicotine (cotinine and trans-3′-hydroxycotinine). The correlations persisted after stratifying for the type of cigarette smoked. Our findings support previous research that NNAL and cotinine are significantly correlated among smokers (23
). This result suggests that cotinine and trans-3′-hydroxycotinine in smokers' urine are indicative of the levels of total NNAL and total PAHs in Chinese herbal and regular smokers due to smoking.
Herbal smokers who switched to herbal cigarettes from regular cigarettes reported increased cigarette consumption after switching. Because of the cross-sectional design, the current study was not able to examine the effect of this increased consumption on the nicotine and carcinogen intake from tobacco smoke. It would be of interest for future studies, especially with short or long-term switching experimental designs, to examine whether it was the health messages and/or the herbal additives that triggered this increased consumption.
Many of the herbal constituents in herbal cigarettes present therapeutic benefits if used alone (generally taken orally, rather than burned and smoked). When burned with processed tobacco and inhaled, these herbal constituents are likely to undergo complex physical and chemical changes. Of the three main herbal brands in China, Wuyeshen, Jinsheng
, we did not find any literature evaluating the health benefits of Jinsheng
. Three studies examined the safety claims of Wuyeshen
). One study found reduction of tobacco-specific nitrosamines in mainstream smoke compared to regular cigarettes (17
). The other two studies found lower toxicological effects from test animals smoking Wuyenshen
and reduced deaths in mouse embryonic cells and human endothelial cells in in vitro
). None of these studies were conducted by independent researchers: one was by a researcher from the tobacco company that manufactured Wuyeshen
) and the others by researchers with close ties with the tobacco industry (15
). A full independent evaluation of the final products, which is yet to be undertaken, would be necessary before any conclusion can be reached to support claims of therapeutic effects of herbal cigarettes.
The marketing of herbal cigarettes as safer products by the Chinese tobacco industry, though unfounded, has been effective; we found health concern to be the second most reported reason for smokers to switch to herbal cigarettes ().
In 2001, Jinsheng
were among 36 most prestigious brands selected by CNTC out of hundreds of brands in China (25
). With a strong foothold in several provinces in China, several herbal brands are being exported to Japan, Korea, countries in Southeast Asia and North America (1
). Because of the health benefits the marketing implies and the fact that smokers in many of these countries are more health conscious, herbal cigarettes is, albeit slowly, gaining popularity in these countries. Local regulatory agencies should be aware of the unsubstantiated health claims and take measures to restrict the marketing of herbal cigarettes.