The Union of Concerned Scientists explains how they do it. To sum up:
Corporations suppress research. (“After pork producers contacted his supervisors, a USDA microbiologist was prevented from publishing research showing that emissions from industrial hog farms contained antibiotic-resistant bacteria.”)
They ghostwrite articles. (“A 2011 analysis found evidence of corporate authorship in research articles on a variety of drugs, including Avandia, Paxil, Tylenol, and Vioxx.”)
They create front organizations. (“The Center for Consumer Freedom is a nonprofit that targets dietary guidelines recommended by the FDA, other government agencies, medical associations, and consumer groups. It was founded with a $600,000 grant from Philip Morris, but has also received funding from Cargill, National Steak and Poultry, Monsanto, and Coca-Cola.”)
They corrupt advisory panels. (“A few weeks before a CDC advisory panel met to discuss federal lead standards, two scientists with ties to the lead industry were added to the panel. The committee voted against tightening standards.”)
