Western diet increases colorectal cancer risk in Japanese women: Cohort study

This was the key finding of research undertaken by academics in Japan and Korea, who assessed 93,062 subjects (43,591 men and 49,471 women).

They were followed between 1995 and 1998 to the end of 2012, during which 2,482 cases of colorectal cancer (CRC) were identified.

Dietary data was obtained from a validated food-frequency questionnaire between 1995 and 1998, and participants were grouped into three distinct dietary patterns.

The ‘prudent pattern’ was characterised by high intakes of vegetables, fruit, noodles, potatoes, soy products, mushrooms, and seaweed.

The ‘westernised pattern’ was heavily loaded on meat and processed meat, eel, dairy foods, fruit juice, coffee, tea, soft beverages, sauces, and alcohol.

The ‘traditional pattern’ had high loadings of pickles, seafood, fish, chicken, and sake (males only).

The prudent dietary pattern was associated with a decreased risk of CRC and colon cancer in the men, whereas a westernised dietary pattern was found to be associated with an increased risk of colon and distal cancer in women.

Meat intake​

“The westernised dietary pattern had a significant trend toward a higher risk of colon and proximal tumours in Japanese women,”​ wrote researchers in the journal Clinical Nutrition.​

“This may be partly due to the effect of red meat and processed meat, a key component in westernised diets, on colorectal carcinogenesis. In this regard, intake of red and processed meat leads to greater ingestion of heme iron which may cause…an increased risk of colorectal cancer.”​

With regard to the traditional Japanese dietary pattern, there was no apparent association with the overall or any specific risk of CRC.

They concluded that the results suggest that dietary patterns can play a significant role in the prevention of CRC.

They added: “We observed that a prudent pattern, featured by high consumption of noodles, potatoes, soy products, vegetable, fruit, mushrooms, and seaweed was associated with a reduced risk of CRC and colon cancer among men, whereas (a) Westernised dietary pattern, typified by frequent consumption of meat and processed meat, eel, dairy products, fruit juice, coffee, tea, soft drink, sauces, and alcohol had a tendency to increase the risk of colon and distal (cancer) among women. These results suggest that (a) dietary approach based on (a) dietary pattern has significance for the prevention of CRC.”​

Source: Clinical Nutrition​

https://doi.org/10.1016/j.clnu.2017.04.015​

“Dietary patterns and colorectal cancer risk in middle-aged adults: A large population-based prospective cohort study”​

Authors: Sangha Shin, et al.​