High sodium intake of children through 'hidden' food sources and its association with the Mediterranean diet: the GRECO study.

OBJECTIVES: Sodium is the mineral that has been, mainly, linked to hypertension and cardiovascular disease. It is found naturally in many foods, but is also used in the food industry and manufacturing. Identification of total sodium intake, as well as 'hidden' sodium intake from food sources early in life is necessary.
METHODS: Four thousand, five hundred and eighty children aged 10-12 years were enrolled, in a cross-sectional, population-based survey. Among other measurements, dietary data were obtained by a semi-quantitative food frequency questionnaire, and sodium intake was calculated. High sodium consumption was considered an intake over 2200 mg/day. Adherence to the Mediterranean dietary pattern was evaluated using the Mediterranean Diet Quality Index for children and adolescent score (KIDMED score).
RESULTS: Twenty-three percent of Greek children had sodium intake which exceeded the 2200 mg/day recommendation, excluding salt added at table and during cooking. Sodium intake was found elevated in children with moderate and high adherence to the Mediterranean Diet. Additionally, 1 unit increase in KIDMED score (i.e. higher adherence) was associated with 10% [odds ratio (OR) 1.10, 95% confidence interval (CI) 1.07-1.13] increased likelihood of consuming sodium above the median intake (i.e. >1500 mg/day). Thirty-four percent of sodium intake from 'hidden' sources came from bread, processed cereals and white cheese.
CONCLUSIONS: Greek children have an elevated sodium intake from 'hidden' sources and main contributors are foods which are recommended to be consumed on a daily basis according to the Mediterranean Diet Pyramid. These findings should induce manufacturers to reduce the amount of sodium added during processing of 'healthy' foods, especially bread and cheese.