title: Salt tea consumption and esophageal cancer: a possible role of alkaline beverages in esophageal carcinogenesis.
abstract: Salt tea is the most commonly used beverage in Kashmir, India, where esophageal squamous cell carcinoma (ESCC) is the most common cancer. Salt tea is brewed in a unique way in Kashmir, usually with addition of sodium bicarbonate, which makes salt tea alkaline. As little information about the association between salt tea drinking and ESCC was available, we conducted a large-scale case-control study to investigate this association in Kashmir. We recruited 703 histologically confirmed cases of ESCC and 1664 controls individually matched to cases for age, sex, and district of residence. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). Participants who consumed >1,250 ml day(-1) showed an increased risk of ESCC (OR = 2.60, 95% CIs = 1.68-4.02). Samovar (a special vessel for the beverage preparation) users (OR = 1.77, 95% CIs 1.25-2.50) and those who ate cereal paste with salt tea (OR = 2.14, 95% CIs = 1.55-2.94) or added bicarbonate sodium to salt tea (OR = 2.12, 95% CIs = 1.33-3.39) were at higher risk of ESCC than others. When analysis was limited to alkaline tea drinkers only, those who both consumed cereal paste with salt tea and used samovar vessel were at the highest risk (OR = 4.58, 95% CIs = 2.04-10.28). This study shows significant associations of salt tea drinking and some related habits with ESCC risk.
authors.affiliation: Department of Biochemistry, University of Kashmir, Hazratbal, Srinagar, Jammu and Kashmir, India.
authors.forename: Nazir Ahmad
authors.initials: NA
authors.lastname: Dar
authors.forename: Gulzar Ahmad
authors.initials: GA
authors.lastname: Bhat
authors.forename: Idrees Ayoub
authors.initials: IA
authors.lastname: Shah
authors.forename: Beenish
authors.initials: B
authors.lastname: Iqbal
authors.forename: Rumaisa
authors.initials: R
authors.lastname: Rafiq
authors.forename: Sumaiya
authors.initials: S
authors.lastname: Nabi
authors.forename: Mohd Maqbool
authors.initials: MM
authors.lastname: Lone
authors.forename: Farhad
authors.initials: F
authors.lastname: Islami
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000209:etiology*; D016022:Case-Control Studies; D003300:Copper / Q000008:administration & dosage; D004938:Esophageal Neoplasms / Q000209:etiology*; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007194:India; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012306:Risk; D013662:Tea / Q000009:adverse effects*
chemical_list: D013662:Tea; D003300:Copper
keywords: Kashmir; alkaline salt tea; cereal paste; esophageal cancer; samovar