JAMA Oncology: Media sends the wrong message…again

The study last week in JAMA Oncology and its subsequent media coverage once again underlines the issues with the media — and its misrepresentation of the facts — all too clearly. This particular study examined whether or not one platinum-induced fatty acid (PIFA), a rare polyunsaturated fatty acid called hexadecatetraenoic acid (C16:4 n-3), is present in fish oils and if it is absorbed in humans when consumed, not whether it has an effect on chemotherapy. Yet media headlines implied that fish oil consumption can make cancer patients resistant to chemotherapy.


Some key points:


  • No human study has shown that PIFAs may interfere with chemotherapy
  • Multiple human trials suggest that fish oil may improve the effectiveness of chemotherapy and have other benefits to cancer patients, but more research is needed
  • This study only shows that one kind of PIFA is present in some fish oils at micro-molar levels and are absorbed in humans
  • PIFAs can be found in other areas of the diet, for example, and at higher levels, in beef and pork.

These same authors published a mouse study previously, which showed that low levels of PIFAs mediate resistance to platinum-based chemotherapies. Based on that mouse data, they have made the logical leap that if PIFAs are absorbed in humans, the same effect would likely be seen in humans too. However, a number of human trials have shown the opposite, that EPA/DHA and fish oils can actually improve the effectiveness of chemotherapy. More research is needed, but the table below shows the findings from all human randomized, double-blind, placebo-controlled studies on chemotherapy effectiveness:


 

 


Human Clinical Study

Conclusion

Ghoreishi Z et al, 2012

Omega-3 fatty acids may be an efficient neuroprotective agent for prophylaxis against [paclitaxel-induced peripheral neuropathy]. Patients with breast cancer have a longer disease free survival rate with the aid of therapeutical agents.

Homsi J et al, 2009

DHA-paclitaxel was well tolerated in metastatic melanoma patients. Its efficacy as a first-line therapy for metastatic melanoma does not exceed that seen with other single-agent chemotherapies such as dacarbazine. 

Minami Y et al, 2008

The current results indicated that an omega-3 fatty acid-containing diet (Racol) may be beneficial to patients with esophageal cancers who receive [chemoradiation therapy (CRT)] by reducing CRT toxicity.

Bonatto SH et al, 2012

[Fish oil] may be useful in preventing chemotherapy-induced decline in neutrophil number and function.

Murphy RA et al, 2011

Patients in the FO group had an increased response rate and greater clinical benefit compared with the SOC group (60.0% vs 25.8%, P = .008; 80.0% vs 41.9%, P = .02, respectively).

Bougnoux P et al, 2009

DHA during chemotherapy was devoid of adverse side effects and can improve the outcome of chemotherapy when highly incorporated. DHA has a potential to specifically chemosensitise tumours.

 


Furthermore, EPA and DHA have been suggested in clinical studies to reduce muscle loss, minimize side effects, and exert anti-inflammatory and immuno-modulatory actions in cancer patients.