Aluminium and human breast diseases

The human breast is exposed to aluminium from many sources including diet and personal care products, but dermal application of aluminium-based antiperspirant salts provides a local long-term source of exposure. Recent measurements have shown that aluminium is present in both tissue and fat of the human breast but at levels which vary both between breasts and between tissue samples from the same breast. We have recently found increased levels of aluminium in noninvasively collected nipple aspirate fluids taken from breast cancer patients (mean 268 ± 28 μg/l) compared with control healthy subjects (mean 131 ± 10 μg/l) providing evidence of raised aluminium levels in the breast microenvironment when cancer is present. The measurement of higher levels of aluminium in type I human breast cyst fluids (median 150 μg/l) compared with human serum (median 6 μg/l) or human milk (median 25 μg/l) warrants further investigation into any possible role of aluminium in development of this benign breast disease. Emerging evidence for aluminium in several breast structures now requires biomarkers of aluminium action in order to ascertain whether the presence of aluminium has any biological impact. To this end, we report raised levels of proteins that modulate iron homeostasis (ferritin, transferrin) in parallel with raised aluminium in nipple aspirate fluids in vivo, and we report overexpression of mRNA for several S100 calcium binding proteins following long-term exposure of MCF-7 human breast cancer cells in vitro to aluminium chlorhydrate.     

Aluminium in human breast tissue

Aluminium is omnipresent in everyday life and increased exposure is resulting in a burgeoning body burden of this non-essential metal. Personal care products are potential contributors to the body burden of aluminium and recent evidence has linked breast cancer with aluminium-based antiperspirants. We have used graphite furnace atomic absorption spectrometry (GFAAS) to measure the aluminium content in breast biopsies obtained following mastectomies. The aluminium content of breast tissue and breast tissue fat were in the range 4-437 nmol/g dry wt. and 3-192 nmol/g oil, respectively. The aluminium content of breast tissue in the outer regions (axilla and lateral) was significantly higher (P=0.033) than the inner regions (middle and medial) of the breast. Whether differences in the regional distribution of aluminium in the breast are related to the known higher incidence of tumours in the outer upper quadrant of the breast remains to be ascertained.     

Correlation between daily life aluminium exposure and breast cancer risk: A systematic review

BackgroundEpidemiological data indicate that the role of environmental factors on breast cancer (BC) incidence remains undetermined. Our daily life exposure to aluminium (Al) is suspected to influence BC development. This review proposes a state of the art on the association between Al and BC risk combined with a critical point of view on the subject.MethodsWe searched the PubMed database using terms related to Al and BC up to November 18, 2022. Reports were eligible if they were cohort or case-control studies or meta-analyses.FindingsSix studies focused on the relationship between deodorant and antiperspirant use and BC incidence and didn’t produce consistent results. Among 13 studies relating Al content in mammary tissues and BC risk, results are not unanimous to validate higher Al content in tumor tissues compared to healthy ones. We detail parameters that could explain this conclusion: the absence of statistical adjustments on BC risk factors in studies, the confusion between deodorant and antiperspirant terms, the non-assessment of global Al exposure, and the focus on Al in mammary tissues whereas a profile of several metals seems more appropriate. The clinical studies are retrospective. They were carried out on small cohorts and without a long follow-up. On the other hand, studies on cell lines have shown the carcinogenic potential of aluminum. Moreover, studies considered BC as a unique group whereas BC is a heterogeneous disease with multiple tumor subtypes determining the tumor aggressiveness.ConclusionIn light of the precautionary principle and based on the data obtained, it is better to avoid antiperspirants that contain Al. Deodorants without aluminum are not implicated in breast cancer, either clinically or fundamentally.     

If exposure to aluminium in antiperspirants presents health risks,its content should be reduced

Since aluminium (Al) pervades our environment, the scientific community has for many years raised concerns regarding its safety in humans. Al is present in numerous cosmetics such as antiperspirants, lipsticks and sunscreens. Al chlorohydrate is the active antiperspirant agent in underarm cosmetics and may constitute for Al a key exposure route to the human body and a potential source of damage. An in vitro study has demonstrated that Al from antiperspirant can be absorbed through viable human stripped skin. The potential toxicity of Al has been clearly shown and recent works convincingly argue that Al could be involved in cancerogenic processes. Nowadays, for example, Al is suspected of being involved in breast cancer. Recent work in cells in culture has lent credence to the hypothesis that this metal could accumulate in the mammary gland and selectively interfere with the biological properties of breast epithelial cells, thereby promoting a cascade of alterations reminiscent of the early phases of malignant transformation. In addition, several studies suggest that the presence of Al in human breast could influence metastatic process. As a consequence, given that the toxicity of Al has been widely recognized and that it is not a physiological component in human tissues, reducing the concentration of this metal in antiperspirants is a matter of urgency.