Do you really believe that red wine—and only red wine among the alcoholic beverages—really reduces the risk of lung cancer?
Last week’s research report that smokers who drink red wine had a substantially decreased risk of developing lung cancer drew such a conclusion. And the media climbed right on the bandwagon.
But I am not so certain that we can reasonably make that connection, and would suggest that until the data is replicated with an even larger study we should be cautious in suggesting that smokers should suddenly switch their adult beverage of choice to red wine from what I suspect is the more typical beer, bourbon and scotch.
The study as reported in the current issue of Cancer Epidemiology, Biomarkers and Prevention did say that their data showed “moderate red wine consumption” was related to a lower level risk for lung cancer. Drink more red wine and you had a much lower incidence of lung cancer if you ever smoked cigarettes. The same effects were not seen with other alcoholic beverages, including white wine.
I am not faulting the researchers for the work they did. In fact, it was a large study of over 84,000 men in California and the methods they used were very appropriate. The study was well done.
But when I was asked to take a look at the article by a reporter for a national news service, I did note some statistics that gave me a moment’s pause. That, combined with my past experience with reports on the health benefits of red wine, suggests to me that we can’t be too quick to say that red wine is good for you if you smoke.
My comments, as correctly quoted in the news report, were essentially that this was interesting research but that it needed to be confirmed. In addition, I also noted that increased wine consumption can be associated with an increased risk of other cancers, including breast cancer and head and neck cancer.
When I reviewed the article in the medical journal, I noted that there in fact was a significant reduction in lung cancer for red wine drinkers who were “ever smokers.” Those reductions, by the statistics, were impressive, up to a decrease of 61% if you drank one or more glasses of red wine a day.
But then I also noted that when the statistics were more carefully examined, the range of possible percentages of the effect of red wine ran from a reduction of as much as 84% to an increase of as much as 78%.
Without getting too complicated on the statistics, the reality was that for each level of red wine consumption, there was a wide range of possible answers (what we call the “confidence interval”) that might have shown up on different analyses of the data in other studies or at different times. The level of certainty was not great that these marked reductions were in fact the “right” answer.
The reason for this is that—despite looking at tens of thousands of men—you would still have to look at thousands more before getting the level of statistical definition that would narrow these confidence intervals and make the statistics more reliable.
When the researchers did an additional analysis, where they looked at the “trend” of the data, the numbers in combination led to the conclusions that they reported in their article, namely that the trend of the data suggested that there was indeed a relationship.
It is important to keep in mind that this type of research is complicated, and so are the statistical analyses. I even asked my statistics colleagues at work to take a look at the numbers, and they essentially came to the same conclusion.
The other question is that although the researchers looked a number of related factors and tried to eliminate them as the cause for the “red wine effect,” I am still concerned that there could have been some other unidentified factor they may not have measured.
This may sound corny, but I just don’t know a lot of smokers who choose red wine as their “alcohol of choice”. Those that do could have other lifestyle habits that separate them from their beer/bourbon/scotch drinking buddies that could theoretically explain the observation in the study.
I have been through the “red wine experience” in the past. I can’t remember the exact time frame, but as best I recall it was in the early 1990’s when there was research touting the health benefits of red wine. Even CBS’ 60 Minutes got into the act, suggesting that red wine consumption may be beneficial, citing the experience of the French who consume larger quantities of red wine without the level of anticipated ill effects.
Since that time, there has been persistent interest in the health potential of red wine—or one of its ingredients—and the possibility that it may be associated with increased longevity.
(I have to laugh a bit at my memories of the red wine story. While in practice as a general internist back in the early 1990’s, an elderly lady—I think she was about 82 years young—who was in reasonably good health came into my office for her regular visit clutching a paper bag. In the bag was a slightly used bottle of red wine. She had seen the television report on red wine, and although she had been a teetotaler before that, she went out and bought herself a bottle of wine and started drinking small amounts.
When she asked me if this was good for her, I advised her that I thought she had been doing fine without the wine. No real objection, mind you, but I wouldn’t recommend to her that she take up this new habit for her health.
At which point, in all seriousness, she turned to me and asked if I thought the wine store would give her money back, since I—her doctors--didn’t think she really didn’t need the wine after all.)
The bottom line: the research is well done, but I don’t have the confidence that I would like to have in the conclusion that red wine drinking reduces your risk of lung cancer if you are or have been a smoker. Any claims along that line should be viewed cautiously.
As the authors correctly concluded in their report:
“We observed an inverse association between red wine intake and risk of lung cancer among ever-smokers, which suggests further research into the lung cancer chemopreventive agents that occur in abundance in red wine. These findings, however, should be confirmed in future epidemiologic studies that separately examine the effect of red wine from other alcoholic beverages.”
To which I say, “Cheers!”
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