Effects of Mediterranean diets with low and high proportions of phytate-rich foods on the urinary phytate excretion.
BACKGROUND
Important health benefits have been reported recently to phytate intake. This includes the prevention of pathological calcifications such as renal calculi, dental calculi and cardiovascular calcification, due its action as crystallization inhibitor of calcium salts, and as preventive of cancer.


OBJECTIVE
The aim of this study was to establish a relation between the intake of phytate, through consumption of typical components of the Mediterranean diet (including nuts), and its excretion in urine.


METHODS
This study recruited participants from subjects included in a larger trial (PREDIMED) of food habits, that were assigned to one of two diet groups: (1) the Mediterranean diet with low proportion of phytate-rich food group, where participants were asked to maintain their usual diet; and (2) the Mediterranean diet with high proportion of phytate-rich food group, where participants were asked to increase phytate-rich foods in their diet. Phytate intake was assessed on the basis of a food frequency questionnaire. Urinary phytate excretion was determined in 2-h urine samples.


RESULTS
The overall phytate consumption of the Mediterranean diet with high proportion of phytate-rich food group (672 +/- 50 mg) was significantly higher than the Mediterranean diet with low proportion of phytate-rich food group (422 +/- 34 mg), representing a 59% difference. Urinary phytate excretion was also significantly higher (54%) in the Mediterranean diet with high proportion of phytate-rich food group (1,016 +/- 70 microg/L) than the Mediterranean diet with low proportion of phytate-rich food group (659 +/- 45 microg/L).


CONCLUSIONS
Mediterranean diets high in whole cereals, legumes and nuts compared to Mediterranean diets low in these phytate-rich foods increase the urinary phytate excretion in humans.
Prieto
Rafael M
RM
Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research IUNICS, University of Balearic Islands, 07122 Palma, Spain. rafelm.prieto@uib.es
Fiol
M
M
Perello
J
J
Estruch
R
R
Ros
E
E
Sanchis
P
P
Grases
F
F
D000368:Aged; D002114:Calcinosis / Q000517:prevention & control; D015179:Colorectal Neoplasms / Q000517:prevention & control; D003430:Cross-Sectional Studies; D038441:Diet, Mediterranean; D002523:Edible Grain / Q000737:chemistry; D007887:Fabaceae / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009754:Nuts / Q000737:chemistry; D010833:Phytic Acid / Q000008:administration & dosage* / Q000652:urine*; D012639:Seeds / Q000737:chemistry; D011795:Surveys and Questionnaires
D010833:Phytic Acid