Does Polyester Cause Cancer?
What is Polyester?
The term 'polyester' is used to refer to a type of synthetic fabric that is widely used in clothing production. However, chemically, the term is broader, encompassing polymer molecules containing an ester moiety in every repeat unit in the chain. A polymer is a molecule that consists of identical large molecules chained together in a chemical reaction known as polymerization. An ester is a molecule that contains an oxygen atom bound to one carbon in a chain by a double bond.
The type of polyester used to make the widely-used fabric is chemically called polyethylene terephthalate. It is important to note that while polyethylene terephthalate is a synthetic polyester, polyesters occur in nature very frequently.
Polyester and Cancer: What is the Evidence?
With the polyester fabric, there are concerns expressed predominantly in the online healthy living community, that this fabric (and other synthetics) are unsafe to wear, and may pose a risk of cancer.
To date, there is no study available that would conclusively prove a causal relationship between exposure to polyester fabric and cancer. This likely indicates that there is no such relationship, given how popular the fabric is.
However, one study indicated that inhalation of polyester fibers was associated with an increased risk of gastric cancers [1]. This study was, however, conducted on a cohort of textile workers in China, who are exposed to a high volume of polyester dust daily. This level of exposure is not comparable to that when wearing a polyester fabric.
Other Chemical Risks With Polyester
While the polyester clothing itself is very likely not carcinogenic, there are additional concerns about some chemicals used in the process of manufacturing polyester.
One such chemical is bisphenol A (BPA). Regular exposure to BPA has been linked to an increased risk of cancer. A study on prostate cancer cells at a relatively low dose found that the ability of these cells to turn cancerous, proliferate, and invade their surrounding tissues [2].
Another chemical concern is a group of chemicals called phthalates, which are used in the manufacturing of plastics. Studies on animals demonstrated an increased risk of cancer upon exposure to phthalates, however, evidence from human epidemiological studies is limited and inconclusive [3].
Can Polyester Cause Other Diseases?
Wearing polyester clothing can potentially lead to a few healthcare complications outside of the realm of cancer.
Bacteria in Polyester
Polyester clothing can harbor some bacteria that can be infectious to humans. A study that analyzed polyester clothing worn by students during exercise classes contained bacterial species including Staphylococcus (21.66%), Enhydrobacter (13.81%), Pantoea (8.14%), Acinetobacter (7.81%), Pseudomonas (6.18%), and Cutibacterium (4.99%) [4]. Furthermore, a study that analyzes nurses' uniforms in hospitals showed contamination with bacteria after their shift, with Escherichia coli being the most abundant (47.8%), followed by staphylococci (19.1%) [5]. This is very important, as E. coli and Staphylococcus are very prevalent hospital-borne infections.
Allergic Reactions
Some polyester clothing can cause allergic reactions in some individuals. This may be from some additives used in the manufacturing process, dyes, or some types of laundry detergent [6, 7]. However, these are easy to treat with topical creams or medicines. Laundry detergents for people with sensitive skin are also available.
Can We Use Polyester to Treat Cancer?
The polyester fabric itself does not have a role in cancer research. However, as some polyesters occur in nature, they have been investigated in cancer treatment as drug delivery vehicles. This is possible due to the natural ability of some polyester molecules to enter cells, making them promising carriers as drug delivery vehicles [4].
For example, polyester micelles, which are round structures with a hydrophobic outside layer and a hydrophilic inside layer, have shown potential in therapeutic and diagnostic applications, with some being investigated in clinical trials [5, 6].
These micelles and other precise drug delivery systems offer an advantage in the ability to target cancer specifically by getting the drugs directly into the tumor. This way, the systemic side effects, such as those associated with conventional chemotherapy, are minimized. Additionally, the local concentration of the drug in the targeted tumor will also be higher, leading to higher efficacy of the drug [8].
One such polyester-based platform is l-amino acid-based amide-functionalized polyester platforms, which self-assemble into nanoparticles and encapsulate the drug [9]. Other systems are Poly(lactic acid) (PLA) and its copolymer, poly(lactic-co-glycolic acid) (PLGA), which have been investigated in delivering immunotherapy to tumors [10].
