Munching on nuts may be protective against oesophageal cancer
Consumption of nuts appears to lead to a reduced risk of oesophageal squamous cell carcinoma (ESCC) in a high-risk population, according to data from the Golestan Cohort Study.
The study included 48,284 participants (mean age 52.1 years; 42.3 percent male; 70.2 percent had no formal education) in Northeastern Iran. Among nut consumers, 11,554 consumed a median of 0.2 g per 1,000 kcal/day (tertile 1), 11,540 a median of 0.9 g per 1,000 kcal/day and 11,857 a median of 2.8 g per 1,000 kcal/day.
There were 280 participants who developed ESCC during a median follow-up of 9 years. Compared with nonconsumers (n=13,333), individuals in the highest tertile of total nut consumption had a lower risk of incident ESCC (adjusted hazard ratio [HR], 0.60; 95 percent CI, 0.39–0.93; p=0.02).
When the effect of each type of nut was examined, a similar risk reduction was observed for the highest tertile of mixed nut and seed intake (adjusted HR, 0.52; 0.32–0.84; p=0.002). In contrast, neither peanut nor walnut was associated with ESCC.
Each 5-g of total nuts consumed per day yielded a statistically significant 29-percent decrease in ESCC risk. On further analysis among nut consumers, the risk decrease was greater for the highest vs the lowest quartile of nut consumption (adjusted HR, 0.59; 0.35–0.99).
Researchers explained that the lack of a significant effect for peanut or walnut consumption could be due to lower intake of peanuts and walnuts relative to mixed nuts and seeds in the present population. It could also be attributed to the different compositions of different types of nuts, as the vitamin, mineral and fatty acid composition differ among types.
Specifically, among nuts and seeds, watermelon and pumpkin seeds are the best source of zinc, which is about three times more than in peanuts or walnuts. Zinc has been reported to be inversely associated with the risk of ESCC. [Am J Clin Nutr 2015;102;102-108; Middle East J Dig Dis 2014;6:177-185]
Additional investigations are required to confirm the present data and to clarify the effect of nut consumption on the risk of total mortality, specific causes of mortality and incidence of other cancers, researchers said.