A major review of medical studies funded by the food industry have found that they are up to 8 times more likely to reach favourable conclusions for a product than studies funded by other means.
This is the conclusion of a group of researchers from the Department of Medicine, Children's Hospital, Boston, in the US, who looked into studies involving soft drinks with supposed health benefits.
So before you act on media reports or company spin regarding any research about the health effects of beverages such as milk, fruit juice or soft drinks, it is a wise idea to find out exactly who paid for the study. If research was funded by a company or group related to the food industry, particularly if this was the sole means of funding, the conclusions may be biased and misleading.
The researchers at the Children's Hospital in Boston, headed by Dr. David Ludwig conducted an extensive review of 206 articles from medical journals that evaluated the health benefits or effects of soft drinks, juice and milk. The studies were all published between 1999 and 2003.
Much of the money available for doing medical research comes from companies, as opposed to government agencies or charities, so with this in mind the researchers wanted to find out what effect, if any, this had on the conclusions reached in research studies. Dr. Ludwig and his team noted prior to their study that there is some evidence that when a research study is sponsored by an organization that has a financial interest in the outcome, the study is more likely to produce results that favour the funder. This is known as a 'sponsorship bias'.
To ensure that that their investigation would not be affected too much by variability between the different types of nutritional research, Dr. Ludwig and colleagues decided to focus on one particular area of nutrition, that of nonalcoholic drinks (including soft drinks, juices, and milk). The researchers examined the published scientific literature to find all original research and scientific review articles relating to nonalcoholic drinks that also fulfilled specific criteria. The studies all described research carried out in humans and at the same time drew conclusions relevant to health or disease.
Following the article selection, each article was reviewed and specific information was recorded. The conclusions of the articles were coded as either favourable, unfavourable, or neutral in relation to the health effects of the products being studied. The funding source for each article was also recorded, either as all industry (ie, food/drinks companies), no industry, or mixed. To prevent bias in this process, one researcher selected the articles for inclusion in the study. Another two researchers who were not told the funding sources classified the articles conclusions toward the beverage studied. A fourth researcher who didn't know the conclusions of the study determined the funding source. Of the 206 published articles that were analyzed 111 supplied information about funding sources, that's only 54% declared funding. Of these, 22% were funded entirely by industry, 32% had both industry and independent funding, and 47% had no industry funding.
The researchers found that, overall, there was a definite link between the type of funding behind an article and the conclusions that were drawn. Amazingly for an endeavor that is supposedly totally objective, articles sponsored exclusively by food/drinks companies were found to be between four and eight times more likely to have conclusions favorable to the financial interests of the sponsoring company than articles which were not sponsored by food or drinks companies.
Following the study Dr. Ludwig was quoted as saying "When a food company sponsors a study, it is much more likely to be positive". He went on, "We found when a food company pays for a study, the results are about eight times more likely to be favourable to the company's financial interest than when the studies are funded independently." Dr. Ludwig concludes that the association is a strong one and that this raises concerns about bias in research.
Studies similar to this one have been carried out in the past with a focus on pharmaceuticals. They have also found a bias when trials are funded by drug companies. Although this is very worrying in itself, Dr. Ludwig believes that bias in studies of beverages could have a greater impact because while only a small proportion of the population will ever use a particular drug, nearly everyone drinks milk, juices or soft drinks. In closing he called for more research on this issue to validate this study's conclusions as well as more independent funding for research.
As a number of commentators have pointed out, you cannot draw the conclusion that all research that is funded, either partly or in full, by industry is biased. A number of important discoveries have been made through the funding and expertise offered by industry. A prime example of this is Unilever's role in determining the effects of trans fatty acids on heart-disease risk. However, this study does raise questions about how much weight we should give studies funded by industry. This is an extremely important question as the boom in 'functional foods' picks up speed.
For those who haven't come across this term before, functional foods are foods or beverages that are reported to have specific health benefits. These benefits usually derive from the addition of specific ingredients that have been shown in research studies to have such a benefit. If we now find that the research these products are based on is biased, how are we to know whether a particular functional food we are buying will actually produce the benefit for our health that it claims it will?
This may be a particularly important question for those of us suffering from environmental illnesses. Diet is a very important part of the equation for recovering and maintaining our health. Functional foods such as yoghurt drinks containing live probiotic 'friendly bacteria' and a host of products containing prebiotics, plant extracts that encourage the growth of friendly bacteria, could be an important addition to an environmental illness sufferers diet. If the science behind such products has been biased in favour of the product manufacturer we could be fooled into thinking a product is doing us a lot more good than it actually is.
So, this is an important study that should serve to open our eyes to the possibility that medical research into functional foods may not be as objective as it should be. When it comes to medical research, or any research for that matter, one single study does not serve to prove anything. Only when a number of studies, preferably with a variety of funders, come to a consensus view can we be confident that a conclusion is valid. So always remember when you are researching anything said to be beneficial to your health; check who paid for a particular study and look at more studies on the same subject to see if they agree with the original study's conclusions.