Moderatore: Staff moderatori
- Messaggi: 1321
- Iscritto il: lun lug 03, 2006 1:28 pm
- Autenticazione: 132435465768
- Località: Oslo, Norvegia.
Eur J Clin Nutr. 2008 Mar;62(3):336-41. Epub 2007 Apr 18.
Oxalic acid does not influence nonhaem iron absorption in humans: a
comparison of kale and spinach meals.
genannt Bonsmann SS, Walczyk T, Renggli S, Hurrell RF.
Institute of Food Science and Nutrition, ETH Zurich, Zurich, Switzerland.
OBJECTIVE: To evaluate the influence of oxalic acid (OA) on nonhaem iron
absorption in humans. DESIGN: Two randomized crossover stable iron
isotope absorption studies. SETTING: Zurich, Switzerland. SUBJECTS:
Sixteen apparently healthy women (18-45 years, <60 kg body weight),
recruited by poster advertising from the staff and student populations
of the ETH, University and University Hospital of Zurich, Switzerland.
Thirteen subjects completed both studies. METHODS: Iron absorption was
measured based on erythrocyte incorporation of (57)Fe or (58)Fe 14 days
after the administration of labelled meals. In study I, test meals
consisted of two wheat bread rolls (100 g) and either 150 g spinach with
a native OA content of 1.27 g (reference meal) or 150 g kale with a
native OA content of 0.01 g. In study II, 150 g kale given with a
potassium oxalate drink to obtain a total OA content of 1.27 g was
compared to the spinach meal. RESULTS: After normalization for the
spinach reference meal absorption, geometric mean iron absorption from
wheat bread rolls with kale (10.7%) did not differ significantly from
wheat rolls with kale plus 1.26 g OA added as potassium oxalate (11.5%,
P=0.86). Spinach was significantly higher in calcium and polyphenols
than kale and absorption from the spinach meal was 24% lower compared to
the kale meal without added OA, but the difference did not reach
statistical significance (P>0.16). CONCLUSION: Potassium oxalate did not
influence iron absorption in humans from a kale meal and our findings
strongly suggest that OA in fruits and vegetables is of minor relevance
in iron nutrition.
(Director, of Harvard's Cardiovascular Epidemiology Program)
Mia mamma continua a dire che il guscio dovrei levarlo perché non ha nutrienti ed è solo scarto che impedisce di assimilare vitamine e minerali.
Io ribatto che masticandoli bene gli acidi dello stomaco distruggono tutto e l'intestino riesce ad assorbire i nutrienti.
Secondo voi chi ha ragione?