Re: Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies
Dietary fibre, whole grains, and risk of colorectal cancer: Historical perspective, Continental variation & Scientific evidence
Colorectal cancer is the second most common cause of cancer mortality (10.4%) in the UK . Aune et al report up to a 20% reduction if 90g of whole grain is consumed daily. This clearly has significant public health benefits: with 5 year survival rates being less than 50%, the cost of bowel cancer is estimated to be £1.1bn per year (in the UK).
The EPIC study suggests that doubling the amount of dietary fibre from 15g to 35g can reduce the risk of colorectal cancer by 40%, with greatest effect seen on the left colon.
However, Chiu et al suggest that fruit and vegetables are more important for reducing risk due to high concentrations of vitamin C, vitamin E and carotene.
In 2005, Norat et al report up to a 1.71% increase in absolute risk of developing cancer in those with a high intake of red meat, especially processed meat. The incidence of colorectal cancer is <1:100,000 in native Africans compared to 60:100,000 in African Americans.
A western diet (high in saturated fat and low in fibre) has often been implicated for the rising rates of cancer. India, which has one of the lowest rates of colorectal cancer worldwide shows an interesting variation in the geographic distribution of colorectal cancer. The incidence of colorectal cancer in rural areas is almost half that of urban areas and Mohandas et al report a 3% annual increase in Mumbai since 1982.
Rastogi et al looked at cancer rates in Indians residing in UK, USA, Singapore and India. They found that colorectal cancer rates were almost eight times higher in US whites, about three times higher among US and UK Asians than in India, and almost twice as high among Singapore Indians.
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Why do African Americans get more colon cancer than Native Africans?
O'Keefe SJ, Chung D, Mahmoud N, Sepulveda AR, Manafe M, Arch J, Adada H, van der Merwe T.
Miss Manaswini Choudhary
Guy's King's & Thomas's Medical School
Mr Rajesh K Choudhary MS FRCS
Department of General Surgery
Darlington Memorial Hospital
Competing interests: No competing interests