The risk of gastrointestinal cancer and nitrate intake due to vegetable consumption: A case-control study in Minab, Iran

Background: Nitrate (NO۳) is a necessary element for plant growth, but its excessive use in agricultural products causes different health problems. This study aimed to investigate the relationship between NO۳ concentrations in vegetables and the prevalence of gastrointestinal cancers in Minab city, Iran. Methods: This case-control study was conducted on ۶۰ people with cancer as the case group and ۱۲۰ healthy people as the control group in Minab city. Data were collected through a questionnaire and measuring NO۳ concentration levels in vegetables. All samples were examined for NO۳ by reverse-phase HPLC (RP-HPLC) method. Results: The concentration levels of NO۳ in all vegetables ranged from ۱۵.۰۸ (onion) to ۱۱۴۳.۵۵ mg/kg (spinach). There was no significant difference between the concentrations of NO۳ in all vegetables among the different regions. The most common cancer in the case group was stomach cancer (۶۱.۷%). There was a significant difference between the amount of daily intake of NO۳, through different vegetables, and the prevalence of gastrointestinal cancer between the case and control groups (P < ۰.۰۵). The results showed that increasing the consumption of vegetables increases the chance of getting gastrointestinal cancer (OR: ۵.۷۲; P < ۰.۰۰۱). Conclusion: According to the results, there is a significant relationship between the NO۳ concentration in vegetables and the prevalence of gastrointestinal cancers in the studied areas. It is highly recommended to closely monitor the cultivation, fertilization, and spray process of agricultural products, and frequent monitoring of NO۳ levels in fruits and vegetables.

Keywords:

Nitrates , Risk assessment , Vegetables , Gastrointestinal neoplasms , Risk cancer