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A Drink a Day Raises Cancer Risk, Study Says

MED and SPH prof on the perils of moderate imbibing


How many of us enjoy a glass or two of wine at dinner? How many of us have read that moderate drinking of red wine is good for the heart?

How many of us know that even moderate drinking might increase our cancer risk?

That eye-catching news turned a few media heads after a recent study was published in the American Journal of Public Health. The authors, including Timothy Naimi, a School of Medicine and School of Public Health associate professor, attribute 6,000 American deaths annually to cancer from moderate drinking, which they define as a drink and a half per day or less. Add in alcohol consumption at all levels and the total surges to 20,000 cancer deaths a year, according to the study. (For perspective, that 20,000 figure represents 3.5 percent of all cancer deaths in the country.)

For men, lethal alcohol-caused cancer typically afflicts the mouth, throat, and esophagus, the researchers say. In women, breast cancer is the most common cancer killer linked to alcohol consumption.

The researchers synthesized risk estimates from hundreds of other studies to come up with their findings. Naimi believes the big takeaway is the total number of deaths, the role of excessive drinking, and the fact that these deaths are preventable. But as everyone knows that drinking to excess is bad for a host of reasons, he understands the headlines generated by the findings on moderate drinking.

Evidence of excessive drinking’s role in cancer is much greater than that for the role of modest drinking, says Naimi, an alcohol epidemiologist specializing in binge and youth drinking and alcohol policy. The idea that limited drinking causes cancer “should be interpreted with caution.…I have nothing against alcohol. My background is as a physician, and my interest is in seeing harm from alcohol minimized.”

But some doctors say the moderate drinking findings need to be taken seriously, and Naimi says there is evidence from the literature he and his team reviewed supporting their concerns. And, he adds, deaths from alcohol “dwarf any small number of people who may derive benefit from low-dose alcohol.” Indeed, among all people who start drinking, 5 to 10 times as many die from it as are benefited by it, according to Naimi, who notes that you can’t predict when people begin drinking whether they’ll wind up an alcoholic: “You don’t know prospectively who’s going to end up as a moderate drinker.”

Nor is he convinced by studies showing heart benefits from moderate drinking. For one thing, he says, those studies have never included the accepted standard in scientific research: a randomized, controlled study comparing moderate drinkers with teetotalers. Also, moderate drinkers tend to come from higher on the socioeconomic ladder, a rung at which people tend to be healthier. In other words, moderate drinking may be “a reflection of people’s social position and good health. It’s not its genesis,” Naimi says.

Studies linking alcohol to cancer are based on calculations using three types of data, he says: the numbers of people who drink at different levels, the prevalence of various cancers at those various drinking levels, and the number of cancer deaths among people at each level. The American Cancer Society lays out the cancers for which the evidence of an alcohol link is strongest, while adding that the precise mechanism for how drinking leads to the disease is not certain.

As for the argument that there’s a certain risk with much of the food we consume—nonorganic fruits and vegetables marinated in pesticides, for example, or brown rice, once thought to be healthy, but now found to contain risky levels of arsenic–Naimi replies, “Alcohol is not a food. Alcohol is a drug,” and one with so-called empty calories that lack nutritional value.

“I wouldn’t put alcohol on a par with fruits and vegetables,” he says—especially as fruits and vegetables won’t kill you the way drunk driving can.

Rich Barlow

Rich Barlow can be reached at barlowr@bu.edu.

17 Comments on A Drink a Day Raises Cancer Risk, Study Says

  • Gerrie on 04.08.2013 at 8:53 am

    Another useless research article that has made headline news. One has to argue did the researchers account for “all” environmental factors. Did they correct for all variables that might in reality skew their results. As with all research caution needs to be applied and the results confirmed.

  • Student on 04.08.2013 at 9:32 am

    Another biased article put out by BU today..

    • Oi on 04.08.2013 at 10:39 am

      Where’s the bias?

      It’s a report on a research study with a few quotes from one of the researchers thrown in.

      • Student on 04.08.2013 at 11:09 am

        Read the comment posted by the Dr. a couple down. I don’t have the time to type out a formal response as I’m in class but that basically sums it up. It’s ridiculous what BU Today will post, always so negataive, liberal based.

        • Huh on 04.08.2013 at 1:01 pm

          How did this become a political issue?

          There may be technical issues with the research itself though neither you nor I are qualified to weigh in on that.

        • Student 2 on 04.09.2013 at 12:18 am

          How is this liberal? This is incredibly conservative. If anything this is just a way for BU to continue to push it’s incredibly anti-alcohol agenda.

  • Cap Buzkil on 04.08.2013 at 10:10 am

    Well, gotta die of something!

  • R. Curtis Ellison, MD on 04.08.2013 at 10:37 am

    The following comment was published on 2-15-2013 on the Boston University web-site: http://www.bu.edu/alcohol-forum.

    Requested comments on paper by Nelson et al
    by R. Curtis Ellison, MD, Professor of Medicine & Public Health,
    Boston University School of Medicine

    Nelson DE, et al. Alcohol-attributable cancer deaths and years of potential life lost in the United States. Am J Pub Health, released February 14, 2013*

    We always welcome new scientific publications that help elucidate factors related to the development of cancer. The new paper by Nelson et al focuses on the role that alcohol consumption may play in the risk of a number of cancers.

    Background: It has long been appreciated that there are a number of upper aero-digestive cancers, such as cancer of the mouth, throat, and esophagus, that occur much more frequently in heavy drinkers, especially alcoholics, than in abstainers. Physiologic studies suggest that these are not diseases of light to moderate drinkers, as a certain amount of alcohol is required to produce these diseases. Similarly, among people consuming enough alcohol to lead to liver cirrhosis, the risk of liver cancer is also markedly increased.

    These “alcohol-related cancers” should be discussed separately from other more common cancers – especially colon cancer and female breast cancer – for which the risk may be only slightly increased by alcohol. In the case of breast cancer, there may be a slight increase in risk among some women consuming an average of only one drink/day (in some studies, such an increase in risk occurs primarily among women who binge drink, have an inadequate intake of folate, and/or are also on hormone replacement therapy.)

    For these types of cancer, it is especially important to consider the net health effects of alcohol consumption. For example, it is estimated that if a woman at average risk of breast cancer (i.e., does not have such a cancer in a first-degree relative) decides to avoid drinking completely in hopes of reducing her risk of breast cancer, her risk of breast cancer would be expected to be slightly decreased, on average, by perhaps 5-10%; however, her risk would be increased of dying from much more common diseases such as heart attack, stroke, or other conditions for which small amounts of alcohol have been shown to reduce risk. And, importantly, her risk of dying of any cause (total mortality) would actually be increased by her avoiding light alcohol consumption.

    The pattern of drinking has often been shown to be even more important than the average amount of alcohol consumed. A stronger association with beneficial effects is seen with the regular (up to daily) intake of small amounts of an alcoholic beverage; drinking larger amounts on fewer days (including binge drinking) is almost always associated with adverse health effects. For example, a man having up to 2 drinks each day would have an average of 14 drinks per week, generally considered to be within recommended guidelines. However, a man consuming 7 drinks on each of only two days each week, despite the same weekly average consumption, would not be considered to be a moderate drinker.

    Comments on the present paper: There are a number of concerns about the analyses and conclusions of the authors of the present paper. These include the following:

    (1) The authors have “corrected” the reported data on alcohol consumption to make up for presumed under-reporting, using a method not generally accepted by statisticians and other researchers. This means that even many “light” drinkers are listed as reporting greater amounts of alcohol.

    (2) The authors do not clearly separate the effects of truly moderate drinking from heavier drinking in their conclusions. They use up to 20 grams of alcohol per day as their lowest drinking category; this is higher than the 14 g/day that is the current definition of responsible drinking for women in the US Guidelines. Further, as stated, if reported intakes are increased artificially, many more light drinkers would be bumped up into higher categories of drinking. The result of this mis-categorization is that bona fide moderate drinking, which has been shown by others to have no association with most types of cancer, is improperly associated in this study with increased cancer.

    (3) The authors’ implications that even regular, moderate drinking increases the risk of many cancers is not consistent with most previous research. Further, by not having data on the pattern of drinking, the authors include binge drinkers in the same category as regular drinkers, further exaggerating the association of cancer with moderate drinking. Others have clearly shown that there are large differences in effect between these two patterns. (It is troubling also that in the paper, the estimated percentage of alcohol-attributable cancer risk among subjects reporting > 0 to 20 grams of alcohol per day is much higher than that of subjects reporting > 20 to 40 grams/day; while this partly relates to the large number of persons who drink only small amounts, such an association makes no sense biologically. It is difficult to understand who the subjects are in the lowest drinking group, but it may include a large percentage of ex-alcoholics or heavier drinkers underreporting their intake. However, this makes any conclusions in this paper regarding the risk of cancer among moderate drinkers highly suspect.)

    (4) The authors do not point out the demonstrated effects of alcohol on total mortality; regular, light-to-moderate drinkers live longer. By focusing only on cancer risks, the authors fail to mention the effects on the risk of much more common conditions, such as coronary heart disease, stroke, dementia, other important health problems of ageing, and on total mortality. The study of the health benefits and problems of drinking is a very mature field — authors generally discuss their observations in the context of total mortality or other major diseases that would be affected by their experimental design. In nearly all cases, light drinking is shown to be beneficial; these studies are ignored here.

    (5) Overall, a criticism of this paper relates to the failure of the authors to put their results into perspective. Statements such as “There is no safe threshold for alcohol and cancer risk” is more of a “scare” statement than a balanced discussion of their results. Given that almost all prospective studies show that regular moderate drinkers have better health as they age and live longer than lifetime abstainers, even papers focused on the effects of alcohol on any particular disease should present a balanced view on its net effects on health and disease.

    (6) Finally, the authors of this paper have taken the results of their analyses (some of which are based on questionable assumptions) as “truth,” then expounding at length about the public health implications. There should always be a certain amount of doubt when presenting the results of an individual study, as no one analysis can possibly reveal everything about an association. (As stated by Voltaire: “Doubt is not a pleasant condition, but certainty is absurd!)

    As the authors acknowledge, observational epidemiologic data can never reveal the full “truth” about the causation of disease from exposures, and each new study’s results must be interpreted taking into consideration previous research. However, the overall implications presented by the authors of this paper suggest that their goal may have been to support a presumed conclusion to discourage alcohol consumption, not to carefully interpret the available data to best advance the public health.

    Key points of these comments
    • There are a number of assumptions taken by the authors in their analyses that raise questions about their results. The authors present only “adjusted” data for reported alcohol intake (based on national sales, not on individual intake), making the relation of alcohol intake to the occurrence of cancer in individuals unclear.
    • There is poor differentiation between regular moderate drinking and periodic heavy drinking (binge drinking) or alcoholism, although there are marked differences in health effects between these groups. Regular, moderate drinking is associated with net health benefits, whereas binge drinking and alcoholism have almost exclusively adverse effects (including increases in many types of cancer).
    • There has been a huge amount of previous research in this field, but the authors do not put their own results into perspective or discuss the overall health effects of alcohol consumption. Previous data have clearly shown that regular moderate drinkers tend to have lower risk of cardiovascular disease, stroke, diabetes, and many other diseases, and have a lower overall risk of all-cause mortality.

    Submitted by
    R. Curtis Ellison, MD
    Professor of Medicine & Public Health
    Director, Institute on Lifestyle & Health
    Boston University School of Medicine
    Co-Director, International Scientific Forum on Alcohol Research

    February 15, 2013

    * Reference for original article: David E. Nelson, MD, MPH, Dwayne W. Jarman, DVM, MPH, Jürgen Rehm, PhD, Thomas K. Greenfield, PhD, Grégoire Rey, PhD, William C. Kerr, PhD, Paige Miller, PhD, MPH, Kevin D. Shield, MHSc, Yu Ye, MA, and Timothy S. Naimi, MD, MPH. Alcohol-Attributable Cancer Deaths and Years of Potential Life Lost in the United States. (Am J Public Health. 2013;103:641–648. doi:10.2105/AJPH.2012.301199)

    • BU undergrad on 04.08.2013 at 12:04 pm

      ^ Thank you!

    • BU alum on 04.09.2013 at 7:11 pm

      Thank you indeed for this incredibly thorough evaluation! It is very appreciated. =)

  • Ahmed on 04.08.2013 at 11:53 am

    “Intoxicants were forbidden in the Qur’an through several separate verses revealed at different times over a period of years. At first, it was forbidden for Muslims to attend to prayers while intoxicated (4:43). Then a later verse was revealed which said that alcohol contains some good and some evil, but the evil is greater than the good (2:219). This was the next step in turning people away from consumption of it. Finally, “intoxicants and games of chance” were called “abominations of Satan’s handiwork,” intended to turn people away from God and forget about prayer, and Muslims were ordered to abstain (5:90-91). (Note – the Qur’an is not arranged chronologically, so later verses of the book were not necessarily revealed after earlier verses.)
    In the first verse cited above, the word for “intoxicated” is sukara which is derived from the word “sugar” and means drunk or intoxicated. That verse doesn’t mention the drink which makes one so. In the next verses cited, the word which is often translated as “wine” or “intoxicants” is al-khamr, which is related to the verb “to ferment.” This word could be used to describe other intoxicants such as beer, although wine is the most common understanding of the word.

    Muslims interpret these verses in total to forbid any intoxicating substance — whether it be wine, beer, gin, whiskey, or whatever. The result is the same, and the Qur’an outlines that it is the intoxication, which makes one forgetful of God and prayer, which is harmful. Over the years, the list of intoxicating substances has come to include more modern street drugs and the like.

    The Prophet Muhammad also instructed his followers, at the time, to avoid any intoxicating substances — (paraphrased) “if it intoxicates in a large amount, it is forbidden even in a small amount.” For this reason, most observant Muslims avoid alcohol in any form, even small amounts that are sometimes used in cooking.”

  • Lou Argow, LPC, LMFT, LSATP (ADDICTIONS) on 04.08.2013 at 12:17 pm

    Social drinking is defined as no more than 2 drinks per occasion, no more than 2 occasions per week. Alcohol abuse is rampant in our sociaty and people are given the message that alcohol is a “natural” and approved beverage, vs. a mood-altering drug. It causes more deaths in this country than anything elee. If automobile accidents with alcohol involved were reported as alcohol-caused deaths, if heart attacks where there is daily alcohol consumption, if accidents where alcohol is a part of the death were reported, then our alcohol lobby industry and advertisements would be out of business. Let’s get real on this.

  • I love this school... on 04.08.2013 at 3:53 pm

    if i put together a shoddily prepared study on the dangers of skewing scientific research towards your viewpoint will BU today publish it?

    I appreciate that alcohol is not good for you, but the risk factors involved in responsible alcohol consumption are tiny compared to hundreds of other things we experience on a day to day basis. Thank god Dr. Naimi is here to save me from the perils of my own decisions.

  • KO on 04.08.2013 at 5:21 pm

    Another useless study. Waste money on something more important please.

  • Anonymous on 04.08.2013 at 6:03 pm

    Give it to me straight, Doc. How long have I got?

  • Kathy on 02.06.2014 at 11:00 pm

    i think it depends on the way of living of that person. I know people who are drinking 1-2 glass of red wine a day and still living healthy. i guess exercise is also a vital key here. is some of the people take part on the research doing a regular exercise?

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