Foods containing omega-3 fatty acids may help in the prevention of early- and late-stage oral and skin cancers, according to a study published in the journal Carcinogenesis.
UK researchers from Queen Mary, University of London grew cell cultures in the laboratory from several different cell lines. These included both malignant oral and skin cancers, alongside pre-malignant cells and normal skin and oral cells.
The focus was mainly on a type of cancer called squamous-cell carcinoma. This is one of the major forms of skin cancer affecting the outer layers of the skin (mainly made up of squamous cells). The researchers point out that squamous-cell carcinoma can also occur in the lining of the digestive tract, lungs and other areas of the body.
Oral squamous cell carcinomas are the sixth most common skin cancer worldwide, the researchers say, and are difficult and expensive to treat.
Omega-3 induced cancer cell death
When the researchers carried out in vitro tests by adding fatty acids into the cell cultures, results showed that omega-3 fatty acids induced cell death in malignant and pre-malignant cells in doses that did not affect normal cells.
Professor Kenneth Parkinson, head of the oral cancer research group at Queen Mary's Institute of Dentistry, says:
"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."
"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," Prof. Parkinson adds.
Potential cure for oral and skin cancers?
The scientists say that because the doses needed to kill the cancer cells did not affect normal cells, this means Omega-3 fatty acids could be used for the prevention and treatment of oral and skin cancers.
Omega-3 polyunsaturated fatty acids are found mainly in oily, fatty fish. Previous research has found that omega-3 may have numerous health benefits, including helping to prevent cardiovascular disease.
Research from the University of Pittsburgh has also suggested that high consumption of the fatty acids can improve memory in young adults.
Increasing omega-3 levels 'may reduce cancer risk'
Because omega-3 cannot be made in large quantities by the human body, the main way to increase levels is to consume foods that are rich in it. Advice on fish and omega-3 fatty acids from the American Heart Association recommends at least two servings (3.5 ounces for each) of oily fish every week.
Many other foods also contain high levels of omega-3, including:
- Ground flax seeds
- Beef (from grass-fed cows)
One of the authors of the study into skin and oral cancers, Dr. Zacharoula Nikolakopoulou from the London School of Medicine and Dentistry, says higher omega-3 intake may be particularly worthwhile for some people:
"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."
Medical News Today spoke exclusively to Dr. Zacharoula Nikolakopoulou about this study and what it means for potential cancer sufferers.
Interview with Dr. Zacharoula Nikolakopoulou
How was the study conducted?
In this study we used several cancer (squamous cell carcinoma) and pre-malignant oral and skin cell lines in culture, which we treated with omega-3 fatty acids.
The effect of the fatty acids on the cell growth and death was assessed, and also the mechanism of action was investigated. We also used normal oral and skin cells to compare the effect.
What did your findings show?We showed that low doses of Eicosapentanoic acid (EPA), in particular, selectively inhibited the growth of pre-malignant and malignant skin and oral cells more than the normal cells in culture, by a combination of growth arrest and apoptosis.
This was partly accomplished by the overstimulation of a cellular pathway triggered by the over-activation of the epidermal growth factor in the malignant and pre-malignant cells.
How could this research be used in the prevention and treatment of oral and skin cancers?
This study suggests that there is a great potential in the use of these fatty acids in the prevention and treatment of these cancers. Together with many other studies done in different types of cancer, our study suggests that the omega-3 fatty acids in diet might protect from oral and skin cancer.
As regards the therapeutic potential, they could also be delivered locally on the tumors in the form of sprays or gels, as these cancers are usually easily accessible.
What are the next steps for this research?
After the initial step, which was to study the effects in vitro, the research should continue by assessing the effects in model organisms in vivo and then in humans in clinical trials, in order to examine the exact effect of these fatty acids and define the appropriate therapeutic doses.