Seasonal Variation of Food Consumption and Selected Nutrient Intake in Linxian, a High Risk Area for Esophageal Cancer in China

Linxian, China, is a region with high incidence of esophageal cancer and a history of poor nutritional status. Nutrition Intervention Trials were conducted in this area from 1985 through 1991 and found a reduction in total cancer mortality in the group receiving supplementation of beta-carotene/selenium/alpha-tocopherol. The positive results of those trials have, in part, been ascribed to the poor nutritional status of this population. To investigate more recent food patterns, nutrient intakes, and seasonal variations in the diet, dietary surveys were conducted among the residents of Linxian in 1996. Food consumption data were collected among 104 households in spring and 106 households in autumn using a method of food inventory changes. Intake of nutrients was estimated and compared to the Chinese Recommended Dietary Allowance (RDA). In both seasons, the five most common food groups consumed were cereals, fresh vegetables, yams, seasonings, and eggs. Low nutrient intakes were found for selenium (79% RDA and 66% RDA), zinc (72% RDA and 62% RDA), vitamin B₂ (64% RDA and 52% RDA), and calcium (53% RDA and 39% RDA) in both spring and autumn. A large seasonal variation was seen in the consumption of leafy vegetables, root vegetables and eggs, all of which might have contributed to the lower intake of vitamin A (25% RDA), vitamin C (75% RDA), protein (76% RDA), and vitamin E (78% RDA) in autumn. These indicate that the nutrient intake in Linxian is inadequate for a number of vitamins and minerals including those shown to be associated with esophageal cancer.