Relationship between urinary amino acids and diets in Spanish Cardiovascular Diseases and Alimentary Comparison Study.

A randomized, cross-sectional study was carried out to examine dietary pattern and urinary amino acids excretion in two Spanish free-living populations. A total of 288 adults (50-54 years old; 50% men and 50% women), randomly selected from the census, took part in the study; of these, 146 were living in an urban district of Madrid and 142 in a rural area. Dietary intakes by 7-day recall questionnaires, smoking habits, and alcohol intake were examined in each participant, and 24-h urine was collected in aliquot cups designed for the Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. All amino acid excretions averaged higher in men than in women in both areas, and higher in the urban than in the rural population. Main dietary differences between urban and rural populations were higher consumption of fish in urban than in rural populations and higher consumption of bread in rural than in urban populations. Urinary taurine excretion as well as 3-methylhistidine or histidine were significantly associated with fish and meat consumptions, respectively, estimated by 7-day dietary recall questionnaires.