Eating oily fish ‘cuts risk of death from bowel cancer’

    20 July 2016

    Bowel cancer patients could increase their chances of surviving the disease by eating oily fish once a week, according to new research from Harvard Medical School.

    The study, published in the BMJ Gut journal, involved analysis of the health records of 170,000 Americans, 1,659 of whom developed bowel cancer over a 10-year period. Of those, 169 died as a result of the disease.

    Researchers found that those who consumed at least 0.3g of omega-3 acids every day were 41 per cent less likely to die from bowel cancer than those who consumed less than 0.1g per day.

    They also found that those who increased their intake to 0.15g per day were 70 per cent less likely to die. Conversely, a 0.15g reduction in omega-3 intake was linked to a 10 per cent increased risk of death from the disease.

    The authors say that further investigation is required, but that if the results can be replicated then patients with bowel cancer might benefit from eating more oily fish. They believe that the fatty acids in salmon, sardines, mackerel, trout and tuna suppress tumour growth and limit the supply of blood to cancer cells.

    Over 40,000 cases of bowel cancer are diagnosed in the UK every year, making it the fourth most common cancer.

    Instant analysis
    Survival rates for bowel cancer typically depend on how quickly the diagnosis is made. Anything that could potentially improve these rates is bound to be of interest and this large American study has enough size and scope for it to be considered important in this area.

    The key finding was that people with bowel cancer who increased their intake of omega-3 fatty acids had a 70 per cent reduced chance of dying from the disease compared to those not taking them. Conversely, reducing intake was linked to a slightly increased risk of dying from the disease.

    It remains unclear — and, as always, more trials are needed here — whether increasing omega-3 levels in the diet directly causes this lower risk but it is sensible anyway to recommend eating more oily fish now and cut down on red meat intake (known to increase bowel cancer risk) as part of a risk-reduction diet for this disease. Regular small amounts of oily fish such as salmon, herring and sardines will be enough and is a simple change to make.
    Research score: 4/5