Do breast implants cause the symptoms that women refer to as “breast implant illness?” Joint pain. mental confusion (“brain fog”), exhaustion, hair loss, dry eyes, depression, and “flu like symptoms that never go away” are just a few of the commonly reported health problems among women with implants that seem to be caused by connective tissue or autoimmune disorders. However, plastic surgeons, breast implant manufactures, and others continue to say that breast implants are “proven safe” and that there is no evidence that these symptoms are caused by breast implants.
These questionable safety claims date back to a meta-analysis of 20 studies, which was published in the New England Journal of Medicine in 2000, and was intended to determine whether breast implants cause connective-tissue diseases. This was essentially the same meta-analysis that was conducted by Judge Pointer’s scientific panel during the law suits against breast implant manufacturers. The authors of the meta-analysis concluded that the studies show no association between silicone breast implants and connective-tissue disease. A careful review of the studies that were included in the meta-analysis reveals that hose studies have a number of flaws, however. The accuracy of any meta-analysis depends on the quality of the studies included in that analysis. We scrutinized these 20 studies in 2000 and pointed out their shortcomings as follows:
- Five of 20 studies cited were not published in peer-reviewed journals. Instead they were papers presented at scientific meetings or unpublished doctoral dissertations. There was therefore limited information on methodology available to evaluate the validity of the study designs.
- The studies do not provide a comprehensive evaluation of diseases among breast implant patients. Most evaluate a few connective-tissue diseases, including such rare diseases as scleroderma. Most do not evaluate the “atypical” connective-tissue disease symptoms or fibromyalgia-type symptoms that many patients report.
- Even for the illnesses that they evaluate, the studies have limitations. In order to conduct an accurate study of implant patients’ health, patients should undergo a comprehensive medical exam. In contrast, most of these studies relied on medical records, which might omit vague symptoms that would be reported in the early stages of disease. Several studies relied on self-report, but only the one that found a significant risk due to implants was criticized because patients might exaggerate their health problems. In contrast, studies that determined whether women had implants based on self-report were included and not criticized as biased, even though it would be expected that some women would fail to mention that they have implants. This failure to report implants is especially likely when information was gathered in person or on the telephone, rather than in a questionnaire.
- Several of the studies relied on hospital records. Very few implant patients would have been hospitalized for their symptoms, since most health problems that implant patients have reported do not require hospitalization.
- The studies included women who had implants for a short period of time, such as a few months or years. If implants cause connective-tissue diseases, it would be expected that the disease would develop over a period of years. Diseases might also be more likely after a silicone gel implant breaks, which usually occurs after 7-10 years. Therefore, a well-designed study would include women who had implants for at least 7-10 years, not an average of 7-10 years.
- Many of the studies do not evaluate the safety of implants for mastectomy patients, and therefore the results may not be relevant to them.
- Many of the samples are too small to study rare diseases, and thus, have limited power to detect increases in the rates of disease, even increases as large as 50-100 percent.
- Older implants (from 1964-75) were made of a thicker silicone shell than newer implants. Those implants were less likely to “bleed” silicone through the shell or to break. Therefore, studies with women who had implants for a wide range of years would not be expected to show a “dose” response, and studies with women having implants for an average of 7-10 years often include many women with implants for very short periods and women with these thicker, potentially less damaging, implants. That minimizes the likelihood of results showing significant risks from implants.
- In at least one of the studies, women were included in study even if they had their breast implants removed shortly after they got them. It is impossible to tell from that study how long the women had breast implants. The other studies do not mention whether women who were identified by medical records as having implants still had them years later. Those omissions potentially bias the findings because women who had implants removed do not have the same amount of exposure as women who have implants continuously.
All articles are reviewed and approved by Diana Zuckerman, PhD, and other senior staff.