Led by Professor Emile Voest, a medical oncologist at the Netherlands' University Medical Centre Utrecht, the researchers work with mice led them to conclude that omega-3 and omega-6 rich products like fish oil supplements should be avoided by those in chemotherapy treatment.
"Where resistance to chemotherapy is concerned, we usually believe that changes in the cancer cells themselves have occurred. Now we show that the body itself secretes protective substances into the blood that are powerful enough to block the effect of chemotherapy," said Professor Voest.
"These substances can be found in some types of fish oil."
But Harry Rice, PhD, vice president in regulatory and scientific affairs at the Global Organization for EPA and DHA Omega-3s (GOED), said the evidence was far from conclusive.
“Advice to abstain from fish oil during chemotherapy should not be based on results from the most recent research conducted in animals,” Rice said.
“Likewise, advice to take fish oil during chemotherapy should not be based on results from studies like the one published last month in which fish oil supplementation increased chemotherapy efficacy in patients with advanced lung cancer. Results from each study are like puzzle pieces."
"Only when the puzzle approaches completion can sound advice be given. This puzzle is far from complete.”
The researchers focused on a form of chemo called cisplatin, typically used to treat lung, bladder, ovarian and testicular cancer.
Writing in the journal Cancer Cell, they found that platinum-induced fatty acids (PIFAs) produced by bodily stem cells inhibited cisplatin treatments, and a similar effect was observed in mice fed, "normal amounts of fish oil,".
In light of the research, Cancer Research UK advised cancer patients to consult with doctors.
“We demonstrate that endogenous mesenchymal stem cells (MSCs) become activated during treatment with platinum analogs and secrete factors that protect tumor cells against a range of chemotherapeutics,” the researchers said.
“Through a metabolomics approach, we identified two distinct platinum-induced polyunsaturated fatty acids … that in minute quantities induce resistance to a broad spectrum of chemotherapeutic agents. Our findings show that MSCs are potent mediators of resistance to chemotherapy and reveal targets to enhance chemotherapy efficacy in patients.”
‘Mesenchymal Stem Cells Induce Resistance to Chemotherapy through the Release of Platinum-Induced Fatty Acids’
Authors: Voest, E. et al