Geographical Distribution of Fast Food and CRC Incidence in Young Adults

Abstract

Background: There is an increasing trend of colorectal cancer (CRC) in young adults who also used to take fast food. However, little is known about the association between fast food and the occurrence of CRC in young adults. Aim: To investigate the impact of fast food diet on the incidence rate of CRC in terms of geographic distribution. Methods: Geographic distribution of fast food diet was measured by the density of fast food stores (numbers of fast food stores/population per 105) according to each county. We summed up total numbers of the fast food stores ranking the top 3 in Taiwan from the corresponding official Web sites. The incidence of CRC from 2004 to 2013 for young adults aged 15 to 49 years old was computed from Interactive Information System of the National Cancer Registry, provided by Health Promotion Administration, Ministry of Health and Welfare. Multilevel random-effect regression model was applied to estimating the effects of geographical location of fast food stores at city/county level on incidence of CRC with adjustment for age and gender at individual level. Results: The incidence rate of CRC in young adults aged 50 years or below was in parallel with the distribution of fast food stores in geographical pattern. After adjusting for age and sex, the results show that an increase in the growth of 1 unit of density in fast food store led to an increase in incidence of CRC by 2%. Approximately 87% accuracy was noted in predicting the highest one-third percentage of incident CRC cases in young adults. Conclusion: The density of fast food stores was highly associated with the increased risk of colorectal cancer incidence in young adults. This may account for the increasing trend of CRC in young adults in Taiwan.