Previous studies showed intake of nuts may affect the risk of upper gastrointestinal (UGI) cancers, but most current evidence comes from Western populations and data from Asia are limited. Cancer rates differ between countries as does nutritional status, which may lead to different associations in different populations. Therefore, we evaluated the association between intake of nuts and the risk of esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and gastric non-cardia adenocarcinoma (GNCA) in a Chinese cohort.

In 1984, 29,584 study participants aged 40–69 completed a baseline questionnaire that included demographic characteristics, lifestyle factors and some dietary questions, including intake of nuts. The Linxian general population trial cohort was actively followed-up through 2016 to collect death endpoints from all causes of death. Adjusted hazard ratios and confidence intervals for UGI cancers by intake of nut frequency groups were estimated by using multivariate Cox regression models adjusted for age, sex, BMI, education level, tobacco smoking, and alcohol drinking.

A total of 5470 incident UGI cancers were identified, including 3128 ESCC, 1712 GCA and 630 GNCA. Sixty-three percent of participants did not consume nuts, while 27% had nuts once per month, 8% consumed nuts 1–3 times/week, and 2% had nuts 4+ times/week. Compared to no nut consumption, no effect for any category of nut consumption was observed on risk of UGI cancers. The HRs for the highest nut consumption group (4+ times/week) compared to no nut consumption were 0.93 (95%CI: 0.72–1.21), 1.23 (95%CI: 0.86–1.76), and 1.12 (95%CI: 0.62–2.03) for risk of ESCC, GCA, and GNCA, respectively. Further, no monotonic trends were seen between level of nut consumption and risk of any specific UGI cancers.

We observed no association between intake of nuts and the risk of ESCC, GCA, or GNCA in a nutrition-deprived rural population in China.