Critique 239: Does the source of funding of epidemiologic studies on alcohol and health affect their results? 28 May 2020

Vos M, van Soest APM, Wingerden T, Janse ML, Dijk RM, Brouwer RJ, deKoning I, Feskens EJM, Sierksma A.   Exploring the Influence of Alcohol Industry Funding in Observational Studies on Moderate Alcohol Consumption and Health.  Adv Nutr 2020: pre-publication.

Authors’ Abstract

Funding of research by industry in general can lead to sponsorship bias. The aim of the current study was to conduct an initial exploration of the impact of sponsorship bias in observational alcohol research by focusing on a broad spectrum of health outcomes. The purpose was to determine whether the outcome depended on funding source. We focused on moderate alcohol consumption and used meta-analyses that are the basis of several international alcohol guidelines. These meta-analyses included observational studies that investigated the association of alcohol consumption with 14 different health outcomes, including all-cause mortality, several cardiovascular diseases and cancers, dementia, and type 2 diabetes.

Subgroup analyses and meta regressions were conducted to investigate the association between moderate alcohol consumption and the risk of different health outcomes, comparing findings of studies funded by the alcohol industry, ones not funded by the alcohol industry and studies with an unknown funding source. A total of 386 observational studies were included. Twenty-one studies (5.4%) were funded by the alcohol industry, 309 studies (80.1%) were not funded by the alcohol industry, and for the remaining 56 studies (14.5%) the funding source was unknown.

Subgroup analyses and meta regressions did not show an effect of funding source on the association between moderate alcohol intake and different health outcomes. In conclusion, only a small proportion of observational studies in meta-analyses, referred to by several international alcohol guidelines, are funded by the alcohol industry.  Based on this selection of observational studies the association between moderate alcohol consumption and different health outcomes does not seem to be related to funding source.

Forum Comments

Whether or not the source of funding of a study automatically leads to bias in its reporting and interpretation of results is an important topic.  In terms of evaluating the association of alcohol consumption to health outcomes, some have argued that funding by the alcohol beverage industry has led to biased reporting, as had previously been shown for the tobacco industry for effects of tobacco on disease and for the pharmaceutical industry for a number of drugs.  However, the alcohol beverage industry, partly due to stringent government limitations set by the US government, has had little to do with the major observational epidemiologic studies that have provided the scientific data upon which guidelines have been developed.

The present study appears to have done an excellent job in evaluating for potential bias affecting the results of seven recent meta-analyses. The outcomes of most of these meta-analyses have been the basis for developing drinking guidelines by governments and other organizations, including the US Dietary Guidelines (USDA), the Dutch nutrition guidelines on alcohol (Health Council of the Netherlands), Australian guidelines to reduce health risks from drinking alcohol (The Health Council of Australia), Nordic Nutrition Recommendation (Nordic Co-operation), and those from Sante Publique France.

Meta-analyses included in the present study were published between 2006 and 2017 (with original studies published from 1961 to 2016).  These meta-analyses were from 386 observational studies relating alcohol intake to a number of health outcomes.  Comparisons were made between those studies funded, to some extent, by the alcohol beverage industry or by non-industry sources.  The authors conclude that (1) only a very small percentage (5.4%) of observational studies of alcohol and health have been done with at least some support from the alcohol-beverage industry; and (2) the extensive analyses described in the present paper show no evidence of bias in results according to the funding source.

Comments from individual Forum members:  Reviewer Ellison stated: “I consider this to be an extremely well-done paper, with most analyses described in great detail.  In fact, the large number of tables in the more than 90-page supplementary material present the raw data for essentially all of the sub-group analyses.  The strengths include the use of results from meta-analyses that have been used as references for several international guidelines for alcohol consumption.  The results of this study are very consistent: they show no evidence of bias in results, or the interpretation of results, based on the source of funding.  In fact, looking at the data presented in the paper, the risk ratios for most outcomes are the same for studies with the two different sources of funding (alcohol-industry vs not-alcohol-industry); and where there are differences, usually the beneficial effects are more pronounced in the non-industry studies.  Personally, I do not see much of a chance for biased interpretation.”

Does the fact that the study was funded by the Dutch Beer Institute affect the results?  While funded by the Dutch Beer Institute, the two senior authors (Feskens and Sierksma) are recognized as legitimate scientists and have published considerably with leaders in the field. Professor Feskens is chair of Human Nutrition and Health at Wageningen University and has recently been the coordinator of FOODBALL, the Food Biomarkers Alliance, the biggest EU project in the field of food biomarkers, funded by the EU Joint Programming Initiative A Healthy Diet for a Healthy Life (  Forum member Mattivi stated: “I consider it relevant to specify that Professor Feskens is a highly respected, leading scientist, and this EU project completed in 2019 under her coordination was to my knowledge the most successful project in the field, in terms of number and quality of the scientific products.”  Also, and more importantly, the authors have gone out of their way to provide a huge supplement that presents the results of essentially all of their analyses that led to their conclusions.

Commenting on the present paper, Forum member Finkel stated: “This is a topic that deserves complete airing.  In the handling of data, it is not the funder that determines whether bias influences a paper, although I am not so naive as to believe that authors are not cognizant of their funding source.  Unfortunately, what is supposed to be objective scientific literature is often polemic driven by bias. The bias may come from the personal, political, religious, or even the perverted scientific views of the authors, by peer pressure, by hope for some sort of personal gain.  Sad to say, editors of well-known journals have been too often complicit, sometimes by abandoning their duties, sometimes even by active participation in the bias.

“The possibility of bias originating at a funding source is obvious, and has frequently been the charge on which opponents of a study’s results have based their attacks, whether or not evidence for such bias exists. This state is especially prevalent in the responses to publication of alcohol research, which seems to evoke too much emotion and not enough cool analysis.  I hope that my colleagues who are expert in the technicalities and nuances of epidemiology will train their sights on this study’s methods, in which I perceive no fatal flaws.  Likewise, I find no sign of bias in the methods or reasoning evinced in this paper. A connection of some of its authors and its funding source do not invalidate the study and conclusions it reports, which, ironically, are the focus of the paper.”

Professor Kenneth Rothman (who many consider one of the very top and clearest-thinking epidemiologists in the world) has published extensively on potential conflict of interest.  He points out that we must judge the relevance of scientific papers by their analytic methods and results, and not automatically exclude those from scientists who could have a potential conflict of interest due to source of funding.  To quote Rothman: “While disclosure may label someone as having a conflict of interest, it does not reveal whether there actually is a problem with the work or whether the implicit prediction is a ‘false positive.’”  He called this “the new McCarthyism in science.”

Forum member Van Velden wrote: “I agree that the source of funding for alcohol-related research does not influence the results of the outcome.  It is important for the alcohol industry that positive as well as negative results on the health implications of alcohol consumptions must be published.  Further, alcohol cannot be seen in isolation, but as part of a healthy and responsible lifestyle.  Alcohol abuse can never be justified, and the industry will never support it.”

Reviewer Goldfinger stated: “This is a very valuable meta-analysis including a large sample of papers.  I was surprised to see how few papers reviewed were actually supported by the alcohol beverage industry. I would have expected far more.  Funding has to come from somewhere, and certainly the industry has a vested interest in research with respect to beverage alcohol and health.  One should not denigrate the value of a study on the basis of funding, and should examine, more so, the scientific method followed, the integrity of the design, and the principles of the authors.”

Member Waterhouse noted: “I think this is a very important paper because it demonstrates that, contrary to some other products such as tobacco or sugar, the alcohol industry has not undertaken an effort to bias the research landscape.  I am curious to know whether other funding entities might have been as unbiased in their funding strategies. It’s a pity the team did not assess other sources.”

Forum member Skovenborg wrote: “I fear that the conclusion of the paper will be disregarded and met with a shrug due to the fact of the association of some of the authors with the Dutch beer sector. That will give some people the excuse not to look at what we consider to be a good and well-done study and to smear the study right away.

“This is an impressive analysis comparing results obtained from studies funded or not by the industry,” stated reviewer Estruch. “The number of studies funded by the alcohol industry is very low.  The conclusion is that the results in favor of the protective effects of moderate alcohol consumption on health are independent of the type of funding received.  These results represent important information that should be taken into account to counter many criticisms of the positive health effects of moderate drinking demonstrated in many papers.”

Reviewer de Gaetano wrote: “I would add that the pressure of anti-alcohol lobbies in Europe (and in Italy too), mainly under the influence of North European Countries, where drinking in moderation is not a tradition, is such that the European Commission does not presently plan to propose any future research call on alcohol and health.  Thus, studies on alcohol and health supported by industry may not be a good answer, but public support for such research is not available.  As a personal note, The Lancet in the last few years has been promoting a strong and persistent campaign against any alcohol consumption.  When reading the full articles, in fact, what is referred to as ‘alcohol harm’ is almost regularly ‘alcohol abuse harm,’ but the lay press reads only the titles.”

Reviewer MeEvoy stated: “I agree that this is a very well conducted, important study.  The results demonstrate that there is no bias towards reporting of favorable associations of moderate alcohol with health outcomes in the alcohol beverage industry-funded studies that were included in this analysis.  While I believe that the authors were justified in focusing on observational studies used to influence alcohol use guidelines, it is important to keep in mind that this likely resulted in a bias towards more scientifically rigorous studies, a limitation the authors acknowledge.  We do not know whether results from a more exhaustive literature review would differ from those reported here; or whether the proportion of industry-supported studies would differ if less rigorous studies were included.  This does not detract, however, from the key point that all studies need to be evaluated on their scientific merits, regardless of the source of funding.”

Forum member Lanzmann noted: “In addition to the discussion of potential conflict of interest, I think that the participation of wine producers might be a good idea to help in the identification of the type of beverage in studies; often, only total alcohol consumption is considered.  This makes it impossible to be able to differentiate the correlations of the different alcoholic beverages because the data are lacking, not taken in account, or the size of the population is not large enough, etc.  The effects of very different beverages such as wine, beer, and spirits, are therefore put into the same basket, whereas I believe that they have different effects, sometimes opposite to each other.”

Overview of topic by Forum member Stockley:  “There have been previous ‘analyses’ of alcohol industry funding of research and ‘conflict of interest’ in public health.  In 2009, Babor et al concluded that ‘while industry involvement in research activities is increasing, it constitutes currently a rather small direct investment in scientific research, one that is unlikely to contribute to alcohol science, lead to scientific breakthroughs or reduce the burden of alcohol-related illness.’ While the current paper by Vos et al also shows that industry involvement in research is still small, approximately 5.4%, the authors also show that based on their selection of observational studies the association between moderate alcohol consumption and different health outcomes does not seem to be related to funding source.  More importantly, the present study shows that the alcohol industry has funded research not only on favourable health outcomes associated with moderate alcohol consumption (such as coronary heart disease and type 2 diabetes), but also on health outcomes adversely associated with alcohol consumption, including breast and colorectal cancer.

“The results of this thorough analysis also clearly demonstrate that the alcohol industry is not ‘big industry’ like the pharmaceutical industry or the tobacco industry.  With such sponsorships,   similar analyses have often conversely suggested that sponsorship of drug and device studies by the manufacturing company leads to more favourable efficacy results and conclusions that cannot be explained by the standard ascertainment of  ‘risk of bias’ assessments (Lundh et al. 2017).”  This does not seem to be the case for research on moderate alcohol consumption.

References from Forum review

Babor TF. Alcohol research and the alcoholic beverage industry: issues, concerns and conflicts of interest. Addiction. 2009 Feb;104 Suppl 1:34-47. doi: 10.1111/j.1360-0443.2008.02433.x.

Health Council of the Netherlands. Alcohol – background document for the Dutch Dietary Guidelines 2015. The Hague: Health Council of the Netherlands; 2015. Publication no. A15/05.

Lundh A, Lexchin J, Mintzes B, Schroll JB, Bero L. Industry sponsorship and research outcome. Cochrane Database Syst Rev. 2017 Feb 16;2:MR000033. doi: 10.1002/14651858.MR000033.

Nordic Co-operation. Nordic nutrition recommendations 2012: Integrating nutrition and physical activity. 5thed. Copenhagen:Nordic Council of Ministers; 201.

Rothman KJ.  Conflict of interest: the new McCarthyism in science.  JAMA 1993:269:2782-2784.

Santé publique France.  Avis d’experts relatif à l’évolution du discours public en matière de consummation d’alcool en France.  Saint-Maurice: Santé publique France; 2017.

The Health Council of Australia.  Australian guidelines to reduce health risks from drinking alcohol. National Health and Medical Research Council (HHMRC);2009.

USDA. Report of the Dietary Guidelines Advisory Committee.  Dietary Guidelines for Americans 2010.  Nutr Rev 2010;53:376–379.

Forum Summary

Funding of research by industry can lead to sponsorship bias.  The aim of the current study was to evaluate for sponsorship bias in observational alcohol research by focusing on a spectrum of health outcomes related to moderate alcohol consumption.  The authors utilized data from seven recent meta-analyses that included information from 386 observational studies of the relation of moderate alcohol consumption to a large number of health outcomes, including cardiovascular diseases, cancer, and mortality.

The authors report that only 5.4% of studies had some support from the alcohol industry, while 80.1% were funded by governments or other sources (non-industry-funded).  Further, the results of moderate drinking on almost all health outcomes (including cardiovascular diseases and cancer) were essentially the same whether the study was funded by the beverage industry or not.  Where there were slight differences, the results from non-alcohol-industry sources tended to have more favorable health results from moderate drinking than did those sponsored by the industry.  The authors end their discussion stating: “In conclusion, only a small proportion of observational studies in meta-analyses, referred to by several international alcohol guidelines, are funded by the alcohol industry.  Based on this selection of observational studies the association between moderate alcohol consumption and different health outcomes does not seem to be related to funding source.”

Forum members considered that the analyses were very complete, and detailed data were given in the very exhaustive supplementary material provided (exceeding 90 pages).  (This makes it possible for a reevaluation of their results by others.)  While Forum members noted that this analysis was apparently supported by the Dutch Beer Institute, the extensive data presented provide no evidence that there was bias in any of the analyses, upon which most international drinking guidelines have been based.  The Forum concludes that the major studies that have shown that moderate drinking can have health benefits, especially for coronary heart disease and type 2 diabetes, are not based on bias because of support from the alcohol beverage industry.

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Comments of this critique by the International Scientific Forum on Alcohol Research have been provided by the following members:

Giovanni de Gaetano, MD, PhD, Department of Epidemiology and Prevention, IRCCS Istituto Neurologico Mediterraneo NEUROMED, Pozzilli, Italy

R. Curtis Ellison, MD, Professor of Medicine, Section of Preventive Medicine & Epidemiology, Boston University School of Medicine, Boston, MA, USA

Ramon Estruch, MD, PhD, Hospital Clinic, IDIBAPS, Associate Professor of Medicine, University of Barcelona, Spain

Harvey Finkel, MD, Hematology/Oncology, Retired (Formerly, Clinical Professor of Medicine, Boston University Medical Center, Boston, MA, USA)

Tedd Goldfinger, DO, FACC, Desert Cardiology of Tucson Heart Center, University of Arizona School of Medicine, Tucson, AZ, USA

Dominique Lanzmann-Petithory, MD, PhD, Nutrition Geriatrics, Hôpital Emile Roux, APHP Paris, Limeil-Brévannes, France

Fulvio Mattivi, MSc, Department of Cellular, Computational and Integrative Biology – CIBIO and C3A, University of Trento, Italy

Linda McEvoy, PhD, Department of Radiology, University of California at San Diego (UCSD), La Jolla, CA, USA

Erik Skovenborg, MD, specialized in family medicine, member of the Scandinavian Medical Alcohol Board, Aarhus, Denmark

Creina Stockley, PhD, MSc Clinical Pharmacology, MBA; Adjunct Senior Lecturer at the University of Adelaide, Australia

Pierre-Louis Teissedre, PhD, Faculty of Oenology–ISVV, University Victor Segalen Bordeaux 2, Bordeaux, France

David van Velden, MD, Dept. of Pathology, Stellenbosch University, Stellenbosch, South Africa

Andrew L. Waterhouse, PhD, Department of Viticulture and Enology, University of California, Davis, USA