Eating fish may protect against oral and skin cancers
London: Omega-3 fatty acids, found in oily fish such as salmon and trout, selectively inhibit growth and induce cell death in early and late-stage oral and skin cancers, according to a new study.
Scientists from Queen Mary, University of London found omega-3 fatty acids induced cell death in malignant and pre-malignant cells at doses which did not affect normal cells.
This suggests they have the potential to be used in both the treatment and prevention of certain skin and oral cancers. Omega-3 polyunsaturated fatty acids cannot be made by humans in large quantities and must be acquired from diet.
The scientists were studying a particular type of cancer called squamous-cell carcinoma (SCC). Squamous cells are the
main part of the outermost layers of the skin, and SCC is one of the major forms of skin cancer.
However, squamous cells also occur in the lining of the digestive tract, lungs, and other areas of the body. Oral squamous cell carcinomas (OSCC) are the sixth most common cancer worldwide and are difficult and very expensive to treat.
In the experiments, the scientists grew cell cultures in the lab from several different cells lines to which they added fatty acids. The cell lines included both malignant oral and skin SCCs, along with pre-malignant cells and normal skin and oral cells.
"We found that the omega-3 fatty acid selectively inhibited the growth of the malignant and pre-malignant cells at doses which did not affect the normal cells," said Professor Kenneth Parkinson, Head of the Oral Cancer Research Group at Queen Mary's Institute of Dentistry.
"Surprisingly, we discovered this was partly due to an over-stimulation of a key growth factor (epidermal growth factor) which triggered cell death. This is a novel mechanism of action of these fatty acids," Parkinson said. Dr Zacharoula Nikolakopoulou, carried out the research while studying her PhD at Queen Mary, under the supervision of Parkinson and Professor Adina Michael-Titus.
"As the doses needed to kill the cancer cells do not affect normal cells, especially with one particular fatty acid we used called Eicosapentaenoic acid (EPA), there is potential for using omega-3 fatty acids in the prevention and treatment of skin and oral cancers," Nikolakopoulou said.
"It may be that those at an increased risk of such cancers – or their recurrence – could benefit from increased omega-3
fatty acids. "Moreover, as the skin and oral cancers are often easily accessible, there is the potential to deliver targeted doses locally via aerosols or gels. However further research is needed to define the appropriate therapeutic doses," she said.
The study was published in the journal Carcinogenesis.