If you have a question about blood sugar, an obvious place to go is the American Diabetes Association's website. Bone density? The National Osteoporosis Foundation. Gender differences in heart disease? The Society for Women's Health Research. These are the gold standard, national authorities, keepers of impartial information—at least that's what you'd assume from their names. But watchdog groups and some experts say they may be putting the interests of drug companies ahead of yours.

In order to operate, associations like these rely on donations and grants, and the pharmaceutical industry has been more than willing to help out. A survey conducted by New Scientist magazine found that out of 19 randomly selected health organizations providing financial information, only two—the National Women's Health Network and Breast Cancer Action—outright refused money from drug companies; 14 others received it, including the American Heart Association and the National Multiple Sclerosis Society. "Yes, we certainly do take money from the healthcare industry," says Jo Parrish, vice president of institutional advancement at the Society for Women's Health Research. "Not working with them cuts our chance to work with the people who are doing the bulk of health research." Outside experts acknowledge her point but call for more transparency. "These groups should disclose not only the amounts of money received," says Jerome Kassirer, MD, former editor in chief of The New England Journal of Medicine and author of On the Take: How Medicine's Complicity with Big Business Can Endanger Your Health, "but also the ways in which that money is designated and the kind of influence it has within the organization."

If you're looking for health information, Kassirer and others give this advice:

• Though these associations are still useful sources, don't rely on just one.

• Try checking for a group's financial ties at integrityin Science.org, run by the Center for Science in the Public Interest. (In the search box, click on Search Universities and Nonprofits.)

• Confirm information from any drug company–funded site with government or academic research institutes, such as the National Institutes of Health (NIH.gov), Centers for Disease Control and Prevention (CDC.gov), MedlinePlus (MedlinePlus.gov), and Mayo Clinic (MayoClinic.com).