Teasing out the truth can be tricky when the subject is breast implants; the vagaries of health are involved and money _ lots of money _ rides on the answers.
Getting people to believe the truth can be stickier.
The question is simple. Have silicone breast implants damaged the health of at least some of the estimated 1-million to 2.2-million women in the United States and Canada who have gotten them since 1962?
Last week, the question got the best answer we probably are going to have. A large-scale study published in the current New England Journal of Medicine reports no link was found between silicone breast implants and connective-tissue diseases or their symptoms. The research done by Harvard Medical School, Harvard School of Public Health and Brigham and Women's Hospital in Boston used data from a long-term study of the health of 87,501 nurses. Of them, 516 had connective-tissue diseases and 1,183 had breast implants, 876 of them filled with silicone gel.
But only three of the women with connective-tissue disease _ rheumatoid arthritis _ had breast implants. Only one had implants filled with silicone _ statistically insignificant.
The results are so definitive and consistent with earlier research that many health experts now consider the case closed. Some are urging the Food and Drug Administration to lift the moratorium on implants imposed in 1992.
The ban resulted from mounting fears that silicone implants were causing a variety of illnesses, particularly connective-tissue diseases such as rheumatoid arthritis and immune-system problems.
French health officials recently lifted their moratorium on silicone implants, saying international research showed women with implants were at no greater risk of autoimmune diseases and cancer than the general population.
But even if medical research can't find a cause-and-effect link between silicone implants and immune-system disorders, the legal system has been eager to do so _ and highly successful.
Billions of dollars are now at stake. Hundreds of thousands of people have a financial _ and emotional _ stake in linking implants to illness, whether it is true or not.
There is no doubt some women have had problems because of breast implants, including localized pain, scar formation, inflammation, enlarged lymph nodes and misshapen breasts because implants have shifted or hardened. Some implants have ruptured or leaked.
What's at issue now is whether leaks, or suspected leaks or just the presence of intact implants can cause a wide variety of immune-system illnesses and other vague symptoms.
It's understandable that many women with painful and disfiguring connective-tissue disorders or immune system problems or any of dozens of other vague symptoms would blame their illnesses on their breast implants.
The more media attention that complaints about implants have gotten, the easier it is for women _ and some of their physicians _ to assume they are responsible for the illnesses for which no other cause is found. When a few women sued implant manufacturers and got multimillion dollar settlements, it became even more tempting to blame implants for a variety of ailments.
The result is one of the largest medical product liability messes in history.
Faced with a growing number of lawsuits, several implant manufacturers agreed to fund a $4.23-billion global settlement fund to pay women enrolled in a class-action case _ even though there is no convincing evidence that implants caused the problems of most of the claimants.
Already, about 400,000 women have filed claims as part of the class action _ far more than can receive the anticipated payments of $140,000 to $1.4-million. An additional 8,000 to 11,000 women are suing implant companies on their own in hopes of larger awards.
Dow Corning Corp. whose share of the class-action settlement pot is $2-billion and who is a major target of the individual suits, threw up its corporate hands and filed for bankruptcy in May. There are no clear answers now as to what will happen to the settlement fund, the individual cases or the whole controversy.
It is difficult to prove a negative beyond any doubt, especially when the health of millions of women is involved, symptoms can be vague and have many different causes and individuals can react differently. When a clear biological link can't be found, researchers have to rely on public health surveys like the Harvard study.
The new research should settle the controversy, but it won't. The study is already under attack. It didn't involve enough women, critics say. It failed to look at symptoms of a new and poorly defined illness some women and doctors attribute to silicone implants. (Harvard researchers said they could not study such vague, subjective and unverified symptoms as fatigue, weakness, decreased ability to sleep, frequent sore throats, dizziness, loss of mental acuity and joint pain.)
Critics also point out that Brigham and Women's Hospital received a research grant from Dow Corning and one of the scientists involved had done eight hours of paid consulting for law firms representing the company.
Ideally, the reaction to this new research should be to cheer its confirmation that implants are not the major danger to women. Ideally, the data should help weed out lawsuits that have no scientific justification so the legal mess can be cleaned up in reasonable time.
Ideally, researchers should be able to get on with finding the causes for the ailments women are suffering and corporations should not be scared off from developing new medical products and drugs that are urgently needed.
But what's likely to happen is just more controversy.
Joan Beck is a columnist for the Chicago Tribune.