In light of recent discussions about vaccines and scientific consensus it is sobering to consider that fully one-third of medical studies turn out to be wrong.

"A study in 2005, published in the Journal of the American Medical Association, found that one-third of all medical studies turn out to be wrong."
http://www.livescience.com/health/091026-medical-research-fraud-errors.html

In addition, many remedies of non-scientific origin may be vindicated despite earlier claims from doctors.
"In 2007, scientists showed that honey works better than cough medicines in soothing children's coughs.

"A new review of studies finds 29 percent of cancer research published in high-profile journals had disclosed a conflict of interest.
While it's a good thing that the conflicts were disclosed, the review also found conflicts affect the research outcomes."

"The findings add to a mountain of evidence suggesting you should be skeptical of health and medical advice."
http://www.livescience.com/health/090511-medical-studies-conflict.html

While many may argue that these disclosures are important since they were revealed.  In addition one can hardly argue that all scientific research is flawed in this fashion.  Similarly, this doesn't represent a loop hole where every quack remedy suddenly acquires legitimacy.

In particular, the problem is more insidious because it undermines the very credibility that scientists and doctors rely on when attempting to deal with public health issues.  It is little wonder that counter claims regarding medical practice gain such traction when so much research can be questioned based on conflicts of interest.

One can certainly understand that sometimes errors can occur and peer review can also ensure errors or faulty research can be identified and addressed.  However, that process only works within the scientific community.  The far greater problem is how such events are viewed by the public which is expected to take advice and recommendations seriously.

Until this issue is addressed by the scientific peer community, one shouldn't be surprised when the general public views scientific pronouncements as debatable and subject to alternate interpretations.