Health services are currently facing immense pressure to meet targets for emergency cancer care after COVID-19 disruptions threw NHS facilities into chaos. Careful food intake is paramount for both healthy individuals and cancer patients, as evidence shows what we eat can significantly alter our risk and progressions of the disease. In some past papers, a food widely consumed around the world has been found to double the risk of prostate cancer.
Salmon as a food source is deemed highly beneficial for health because it is an excellent omega-3 fatty acid.
This is true for both wild-caught and farm-raised salmon.
However, while one fish is caught in the open water, the other is raised in confined spaces, which may have implications for health.
A large study published in 2004 found that PCBs in farm-raised salmon were about eight times higher than concentrations in wild salmon, according to Harvard Health publishing.
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Polychlorinated biphenyl (PCB) are man-made chlorinated industrial chemicals.
PCBs have been banned for commercial use for decades, but traces can still be found in the environment, and exposure today occurs mainly through diet.
The Environmental Defence Fund explains the chemicals were previously released into the environment from hazardous waste sites.
Scientists first warned that regularly eating farmed salmon could increase the risk of developing cancer after discovering multiple cases of contamination.
Salmon raised on British fish farms was particularly contaminated with carcinogenic chemicals.
The findings, published in the journal Science, suggest that cheap farmed salmon sold in supermarkets may do more harm than good to the body.
The researchers said: “Risk analysis indicates that consumption of farmed Atlantic Salmon may pose health risks that detract from the beneficial effects of fish consumption.”
They warned that eating farmed salmon more than once a month could be enough to increase the risk of the disease.
In a separate paper published in the journal Environmental Research, the authors explained: “The biologic and toxic effect of PCBs and their metabolites are due in part to their ability to interact with several cellular and nuclear receptors, thereby altering signalling pathways and gene transcription.”
To identify how this process relates to cancer risk, the team conducted a hospital-based, case-control pilot study of 58 prostate cancer cases and 99 controls.
The study added: “In multivariate analyses, the odds of prostate cancer among men with the highest concentrations of moderately chlorinated PCB was over two times that among men with the lowest concentration.
“These results suggest that a higher burden of PCBs may be positively associated with an increased risk of prostate cancer.”
There are several mechanisms involved in the modulation of cancer risk, and each disease is influenced differently.
Further research suggests exposure to certain PCBs may also increase breast cancer risk.
However, according to the Illinois Department Department of Public Health: “There is no evidence that PCBs cause cancer at the low levels normally found in the environment.”
“Studies of human workers exposed to high levels of PCBs, have not consistently shown that PCBs cause cancer,” says the health watchdog.