Critics call the Institute of Medicine (IOM) report Safety of Silicone Breast Implants (1999) obsolete, but many still refer to this report to defend the safety of breast implants in 2025. As a patient organisation, we thoroughly analyzed the report and found that the risk derivatives of pyrogenic amorphic silica . In fact, the IOM quoted research that showed that this silica is toxic to macrophages (immune cells), but ignored self these findings in the conclusions.
The Acknowledged the risk derivatives of pyrogenic amorphic silica as a biocidal product, but allowed its use in breast implants placed close to the lungs. How can this contradiction be reconciled with the identified health risks? (source: RIVM)
Late conclusions on silica
The IOM report mentions silica as a component of breast implant envelope (21-27%), and 16% barrier layer, but found it to be no need examine its toxicity. The summary says: "Since there is no evidence of the availability or presence of any mutagenic silica from implant shells in animal or human tissues or crystalline silica formed in women with implants, the toxicology of silica has not been investigated." This is a crucial omission, because pyrogenic amorphic silica was indeed found in studies.
Below is an analysis of Brautbar et al's research. Several times as reference mentioned in the IOM study but completely ignored the findings of silica.
Analysis of silica in Brautbar et al. (1996)
The Article "Silicone breast implants and autoimmunity: Causation, association, or myth?" (Brautbar et al., 1996) focuses primarily on the immunological effects of silicone breast implants, but also contains important insights on the role of silica (SiO2) autoimmune reactions. Below an important quote.
“By comparing the silica-free silicone and the extracted implant ready shells, a correlation can be made regarding the effects of silica filler. The histologic response to the fumed silica filler. The histologic response to the fumed silica represents the most
intense cellular response matched with those of the other materials. These findings
of silica causing a very intense immunological reaction and the findings with the
NMR spectroscopy described above, that silica is released from the silicone gels
[8, 9], are of extreme importance. Taken together, they mean that silicone is bio-
degradable, releases silica which in turn causes an intense immunological reaction.”
1. Silicone as Immunological Trigger
Main Findings
- Silicone in implants:
- The silicone envelope of breast implants often contains pyrogenic silica as a filler to give mechanical stability (Brautbar et al., 1996, p. 139).
- Off in vivo-studies show that silica is released when silicone is degraded: "Silicone is biodegradable under normal conditions in vivo, and is associated with production of silica products such as silica gel' (p. 136).
- Immunogenicity of silica:
- Silicone (both crystalline and amorphic) is a known adjuvant that activates macrophages and can trigger autoimmune reactions (p. 139):
> "Fumed silica elicited the most highly reactive cellular response... silica has long been known as a significant immunological annoying" (p. 139). - Silicone stimulates T-cell dependent antibody production and may enhance inflammation reactions (p. 139).
2. Mechanism of Silicone Freedom and Effects
Experimental Support
- Animal studies:
- Rats with implanted silicone developed silica-containing compounds in liver and spleen, indicating systemic spread (p. 136).
- Silicona caused granuloma formation and lymphocytes infiltration (p. 134).
- Human data:
- Patients with implants sometimes showed anti-silica antibodies and increased ANA titers (p. 138.
- Silicone in combination with siloxanes (such as D4) can form auto antigens (p. 141):
> "Silicone may function as an adjuvant by inducing changes in the conformation of native molecules' (p. 141).
3. Clinical implications of silica
Autoimmune disorders
- Scleroderma and lupus:
- Silicone is linked to anti-centromeric antibodies and anti-Scl-70, typical of scleroderma (p. 137).
- Patients with implants developed sclerodermia-like symptoms more frequently (p. 137).
- Neurological effects:
- Silicone particles were found in nerve tissue and may cause neuroinflammation (p. 136, 141).
4. Discussion: silica vs. siloxanes
Although the article focuses on silicone (PDMS), it stresses that:
- Silicone is a critical component of implants (as filler).
- Silicone immunologically more active than siloxanes:
"The histologic response to the fumed silica represents the most intense cellular response compared with those of the other materials".
- Degradation of silicone leads to silica formation, enhancing the immune response.
This research supports:
- Silicona plays a key role in the immunogenicity of silicone implants.
- Release of silica (by degradation or as filler) contributes autoimmune reactions (scleroderma, lupus).
- Removal of implants may reduce symptoms, suggesting a causal relationship.
Source: Brautbar et al., Journal of Biomaterials Science, Polymer Edition.
Selective rejection of risk derivatives
The IOM systematically rejected studies demonstrating risk mismatches. For example, studies that found silica in nerves and suggested a link between silicone implants and neurological complaints (such as MS-like syndromes) were rejected as "methodologically deficient." At the same time, the IOM accepted two epidemiological studies that were unrelated to neurological diseases without critical examination of their methodology. These studies had considerable limitations, such as selection bias: They only looked at women who were hospitalized, missing women with milder complaints. Certain diseases were coded only after 1987. Relatively short follow-up, too short to detect progressive disorders. In addition, this research was financed by the . This makes their conclusions unsuitable to ensure the safety of implants.
Example of selective rejection
Page 27 pdf ) However, reports that silicone might be associated with autoantibodies to nervous components, that silica might be present in the nerves of women with implants, or that multiple sclerosis-like or other neurologic syndromes may be associated with
implants have been found to have design and methodological problems that limited any conclusions. Two epidemiological studies of neurologic disease in women with implants provided limited support for a conclusion that there is no increased relative risk for any association, and the committee concludes that with the exception of local problems caused by the migration of gel from ruptured implants, evidence that silicone
breast implants cause neurologic signs, symptoms, or disease is leaking or flawed.
Conflicts of interest and industrial influence
The IOM acknowledges that many studies that did not find any risk derivatives were carried out by industry, such as implant manufacturers. However, it nevertheless accepts these studies as "useful" and "scientifically sound" despite clear conflicts of interest. This suggests a possible bias: studies showing risk derivatives, such as those of Brautbar et al, (in references only) Shanklin and Smalley (1996) on T-cell reactions to silica, were severely criticised, possibly not considered at all, while industry studies were assessed more mildly. This pattern undermines the objectivity of the IOM report. Some examples below:
Toxicology not studied p. 99 pdf (click here to read)
The committee included quotes on the toxicology of silica in the reference list of this report, because there has been considerable mention of silica as a component of breast implant elastomers. However, the toxicology of silica is not reviewed here because the committee found no valid scientific evidence for the presence of or exposure to silica in tissues of women with breast implants.
The envelope of the breast implants p. 79 pdf (click here to read).
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Implant shells are made of silicone rubber, which is, elastomer with a filler. They vary in the composition and characteristics of the elastomer (e.g., approximately 21,77% amorphous silica filler in the elastic for the shell and in shell patches, and 16.5% in barrier coats according to Dow Corning). Specifications of other manufacturers may vary. Amorphous silica is different in its physicalochemical properties and in its biological effects from crystalline silica, which is reported not to be present inmeanurable amounts in implant shells or gels (see Chapter 2; see also IARC, 1997; Iler, 1981). Shell thickness also varieties, ranking from 0.13 to 0.75 mm, or 0.005 to 0.030 inch. Some shells have been even thicker, and areas of some implant shells lie outside this range (J. Curtis, Dow Corning, personal communication, February 17, 1998; P. Klein, Dow Corning, personal communication, August 10, 1998; Z.F.Twardochleb, McGhan Medical, personal communication, July 7, 1998). Most shells have had smooth elastomer rubber, but increasingly, some are textured with different surface features or shell projections of varying coastness, depending on the manufacturer.
What does this mean for women?
By ignoring the risks of pyrogenic amorphic silica, the IOM has for decades abandoned women. This substance can cause immune reactions, such as fibrosis and hairstyle formation, which are consistent with the symptoms of women. As a biocidal product . . . . . . . . . . . . . . . . . . . . . . . . The IOM should have taken these signals seriously instead of trivializing them.
Disclaimer:
The information on this website is intended for informational purposes and is based on carefully collected scientific research. The topics and hypotheses discussed have not yet been widely recognised within the medical community. We are not doctors and do not give medical or legal advice. No rights can be derived from the content of this website. Stichting SVS accepts no liability for any consequences, damage, complaints or legal proceedings arising from the use of this information.
