Lower risk of bowel cancer death linked to high omega 3 intake after diagnosis

There are vegetarian sources of omega-3 fatty acids, such as ground flax seed.

http://www.eurekalert.org/pub_releases/2016-07/b-lro071916.php

Public Release: 19-Jul-2016
Lower risk of bowel cancer death linked to high omega 3 intake after diagnosis
People with the disease may benefit from boosting dietary oily fish content, say researchers
BMJ

A high dietary intake of omega 3 fatty acids, derived from oily fish, may help to lower the risk of death from bowel cancer in patients diagnosed with the disease, suggests research published online in the journal Gut.

If the findings can be reproduced in other studies, patients with bowel cancer might benefit from boosting their oily fish intake to help prolong their survival, say the researchers.

Previous experimental research has shown that omega 3 polyunsaturated fatty acids (PUFAs)--namely, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA)--can suppress tumour growth and curb blood supply to malignant cells (angiogenesis).

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Participants with a higher dietary intake of omega 3 from oily fish were more likely to be physically active, take multivitamins, drink alcohol and to consume more vitamin D and fibre. They were also less likely to smoke--all factors associated with a lower risk of bowel cancer.

But those who had been diagnosed with bowel cancer and whose diets contained higher levels of marine omega 3 had a lower risk of dying from the disease. Omega 3 intake, however, was not linked to a lower risk of death, overall.

The extent of the reduced risk seemed to be linked to dose, with higher doses associated with lower risk, the findings showed. This held true even after taking account of intake prior to the diagnosis, as well as other potentially influential factors.

Compared with patients who consumed less than 0.1 g of omega 3 fatty acids daily, those who consumed at least 0.3 g daily after their diagnosis, had a 41% lower risk of dying from their disease.

This reduced risk applied to food sources and supplements, although few people used omega 3 fish oil supplements, the researchers point out.

The association between marine omega 3 intake and lowered risk of death seemed to be particularly evident among those who were tall, had a BMI below 25, or who didn't take regular aspirin.

And increasing intake of marine omega 3 by at least 0.15 g daily after diagnosis was associated with a 70% lower risk of dying from bowel cancer; while a reduction in daily intake was associated with a 10% heightened risk of death from the disease.

Similar patterns were evident for death from all causes (13% lower and 21% higher, respectively) in those who either increased or decreased their intake after diagnosis.

This is an observational study so no firm conclusions can be drawn about cause and effect, but the researchers say that their findings provide the first line of population based evidence for the potentially positive impact of oily fish omega 3 fatty acids on bowel cancer survival.

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