JACN Did you know that you can get alerts when a new issue is online?
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Joung, H.
Right arrow Articles by Paik, H. Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Joung, H.
Right arrow Articles by Paik, H. Y.
Journal of the American College of Nutrition, Vol. 26, No. 3, 295-302 (2007)
Published by the American College of Nutrition

Fecal Phytate Excretion Varies with Dietary Phytate and Age in Women

Hyojee Joung, PhD, Bo Y. Jeun, MS, Shan J. Li, PhD, Jihye Kim, PhD, Leslie R. Woodhouse, PhD, Janet C. King, PhD, Ross M. Welch, PhD and Hee Y. Paik, ScD

Graduate School of Public Health, Seoul National University, Seoul, KOREA, USDA
Department of Food and Nutrition, Seoul National University, Seoul, KOREA, USDA
Western Human Nutrition Research Center, Davis
Division of Nutritional Genomics, Children's Hospital Oakland Research Institute (CHORI), Oakland, California, USDA/ARS, U.S. Plant, Soil
Nutrition Laboratory, Cornell University, Ithaca, New York

Address reprint requests to: Hee Young Paik, ScD, Department of Food and Nutrition, College of Human Ecology, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, KOREA. E-mail: hypaik{at}snu.ac.kr

Objective: Information on the excretion of dietary phytate in humans under different conditions is limited. The purpose of this study was to investigate fecal excretion of dietary phytate and phosphorus in a group of young and elderly women consuming high and low phytate diets.

Methods: Fifteen young and fourteen elderly women were fed two experimental diets, high phytate and low phytate, for 10 days each with a washout period of 10 days between the two diet periods. Duplicate diet samples from two different menus and complete fecal samples were collected for 5 days during each diet period and analyzed for phytate and phosphorus contents. Mean daily excretions and percentages of dietary intakes of phytate and phosphorus were calculated.

Results: Dietary phytate level does impact phytate excretion, but the effect was observed only in young subjects. Fecal phytate excretion of young subjects during the high phytate diet (313mg/d) was significantly higher than during the low phytate diet (176mg/d), however, that of elderly subjects did not vary with dietary phytate levels. Phosphorus excretion, net absorption, and apparent absorption rate were affected by dietary phytate level but not by the age of the subjects.

Conclusions: Results of this study indicate that phytate degradation in the gastrointestinal tract is substantial and more variable in young women than in elderly women. The high capacity of phytate degradation in elderly subjects may be related to long-term phytate intake but needs further clarification. Both beneficial and adverse health effects of phytate need to be studied considering the long-term phytate intake and age of subjects as well as dietary phytate levels.

Key words: phytate, phosphorus, excretion, excretion rate, women






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the American College of Nutrition.