Dietary fiber intake from fresh and preserved food and risk of nasopharyngeal carcinoma: observational evidence from a Chinese population

Abstract

Background The role of dietary fiber intake on risk of nasopharyngeal carcinoma (NPC) remains unclear. We examined the associations of dietary fiber intake on the risk of NPC adjusting for a comprehensive list of potential confounders. Methods Using data from a multicenter case-control study, we included 815 histologically confirmed NPC incident cases and 1502 controls in Hong Kong, China recruited in 2014–2017. Odds ratios (ORs) of NPC (cases vs controls) for dietary fiber intake from different sources at different life periods (age 13–18, age 19–30, and 10 years before recruitment) were evaluated using unconditional logistic regression, adjusting for sex, age, socioeconomic status, smoking and drinking status, occupational hazards, family history of cancer, salted fish, and total energy intake in Model 1, Epstein-Barr virus viral capsid antigen serological status in Model 2, and duration of sun exposure and circulating 25-hydroxyvitamin D in Model 3. Results Higher intake of total dietary fiber 10 years before recruitment was significantly associated with decreased NPC risk, with demonstrable dose-response relationship (P-values for trend = 0.001, 0.020 and 0.024 in Models 1–3, respectively). The adjusted ORs (95% CI) in the highest versus the lowest quartile were 0.51 (0.38–0.69) in Model 1, 0.48 (0.33–0.69) in Model 2, and 0.48 (0.33–0.70) in Model 3. However, the association was less clear after adjustment of other potential confounders (e.g. EBV) in the two younger periods (age of 13–18 and 19–30 years). Risks of NPC were significantly lower for dietary fiber intake from fresh vegetables and fruits and soybean products over all three periods, with dose-response relationships observed in all Models (P-values for trend for age 13–18, age 19–30 and 10 years before recruitment were, respectively, 0.002, 0.009 and 0.001 for Model1; 0.020, 0.031 and 0.003 for Model 2; and 0.022, 0.037 and 0.004 for Model 3). No clear association of NPC risk with dietary fiber intake from preserved vegetables, fruits and condiments was observed. Conclusion Our study has shown the protective role of dietary fiber from fresh food items in NPC risk, but no association for total dietary fiber intake was observed, probably because total intake also included intake of preserved food. Further studies with detailed dietary information and in prospective settings are needed to confirm this finding, and to explore the possible underlying biological mechanisms.

Incidence and Demographics of Nasopharyngeal Carcinoma in Cheung Chau Island of Hong Kong—A Distinct Geographical Area With Minimal Residential Mobility and Restricted Public Healthcare Referral Network

“…First, we could not provide a clear and representative record of the amount of salted fish consumption and exposure to incense burning of our Cheung Chau patients owing to the retrospective nature of this study. Further to a recently published study in Hong Kong suggesting the role of preserved food in NPC risk, 41 additional studies such as investigations on the lifestyle of patients from Cheung Chau and the subsequent gene-environment interaction of NPC in Cheung Chau are definitely warranted to verify our results. Furthermore, there was a possibility of not collecting Cheung Chau NPC cases managed at other public or private hospitals.…”

Long-term trends of nasopharyngeal carcinoma mortality in China from 2006 to 2020 by region and sex: An age-period-cohort analysis

“…Another factor that increases the risk of NPC is exposure to fumes, smoke, dust, and chemicals [19]. It has been reported that the consumption of fresh fruits and vegetables plays a protective role against NPC [20,21].…”

Relationship Between Dietary Fiber and Vitamin C Intake and Oral Cancer

“…There are relatively few reports on the relationship between dietary fiber consumption and cancer in developing area. A case-control study of 851 cases of nasopharyngeal carcinoma and 1,502 controls conducted in China ( 37 ) reported that dietary fiber intake was negatively correlated with the risk of nasopharyngeal carcinoma. Another study from China showed ( 38 ) that a high dietary fiber intake, particularly from vegetables and fruit, was negatively correlated to the incidence of colorectal cancer in Chinese people.…”