Science Update

Omega-3 intake may help decrease colon cancer mortality after diagnosis

According to a new study published three days ago in Gut researchers concluded that a high dietary intake of omega-3 fatty acids may help decrease mortality in patients with colon cancer.

Previous research has demonstrated that omega-3 fatty acids suppress tumor growth and decrease angiogenesis to malignant cells. For example two months ago I shared a new study published in the journal Molecular Cancer Therapeutics where researchers demonstrated that docosahexaenoic acid (DHA) helps reduce renal cell carcinoma invasiveness growth rate and blood vessel growth when combined with the anti-cancer therapy regorafenib. In addition in a study published in the Journal of Pharmacology and Experimental Therapeutics researchers at Washington State University found a mechanism by which omega-3 fatty acids inhibit the growth and spread of prostate cancer cells.

In this new study the results were based on two large long term studies these being the Nurses' Health Study of 121700 US registered female nurses and the Health Professionals Follow Up Study of 51 529 male health professionals. All participants completed a detailed health history which was repeated every two years subsequently. The information included any diagnosis of bowel cancer as well as and other risk factors. In addition a diet diary was collected and updated every four years using Food Frequency Questionnaires.

In this study there were 1659 participants who developed bowel cancer and as a result 561 died. One hundred and sixty nine of these deaths were a result of the disease during an average monitoring period of 10.5 years.

Participants who had been diagnosed with colon cancer and whose diets contained higher levels of omega-3 fatty acids had a decreased mortality rate from the disease. Thus there was an inverse relationship between omega-3 fatty acid intake and risk of death. The higher dose or intake of fish oil was associated with a lower risk of bowel cancer. This was also true after adjusting the intake prior to the diagnosis. Patients who consumed less omega-3 fatty acids daily had a 41% lower risk of dying from cancer once they increased their intake at the time of diagnosis. This reduced risk was associated with a combination of dietary sources and supplements.

The researchers determined that increasing the omega-3 intake of 0.15 g daily after diagnosis was associated with a 70% reduction in mortality. On the other hand reducing daily essential fatty acid intake was associated with a 10% increased risk in mortality.

Other lifestyle and dietary habits such as exercise increased dietary fiber and vitamin D intake are also associated with a decreased risk of colon cancer.

By Michael Jurgelewicz DC DACBN DCBCN