Effect of potato on acid-base and mineral homeostasis in rats fed a high-sodium chloride diet

Br J Nutr. 2006 May;95(5):925-32. doi: 10.1079/bjn20061742.

Abstract

Excessive dietary NaCl in association with a paucity of plant foods, major sources of K alkaline salts, is a common feature in Western eating habits which may lead to acid-base disorders and to Ca and Mg wasting. In this context, to evaluate the effects of potato, rich in potassium citrate, on acid-base homeostasis and mineral retention, Wistar rats were fed wheat starch (WS) or cooked potato (CP) diets with a low (0.5 %) or a high (2 %) NaCl content during 3 weeks. The replacement of WS by CP in the diets resulted in a significant urinary alkalinisation (pH from 5.5 to 7.3) parallel to a rise in citrate and K excretion. Urinary Ca and Mg elimination represented respectively 17 and 62 % of the daily absorbed mineral in rats fed the high-salt WS diet compared with 5 and 28 % in rats fed the high-salt CP diet. The total SCFA concentration in the caecum was 3-fold higher in rats fed the CP diets compared with rats fed the WS diets, and it led to a significant rise in Ca and Mg intestinal absorption (Ca from 39 to 56 %; Mg from 37 to 60 %). The present model of low-grade metabolic acidosis indicates that CP may be effective in alkalinising urine, enhancing citrate excretion and ameliorating Ca and Mg balance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid-Base Equilibrium / drug effects*
  • Animals
  • Calcium / urine
  • Cecum / metabolism
  • Diet
  • Eating
  • Homeostasis / drug effects*
  • Hydrogen-Ion Concentration / drug effects
  • Intestinal Absorption / drug effects
  • Magnesium / urine
  • Male
  • Minerals / urine*
  • Potassium / urine
  • Rats
  • Rats, Wistar
  • Sodium Chloride, Dietary / administration & dosage
  • Sodium Chloride, Dietary / pharmacology*
  • Solanum tuberosum*
  • Weight Gain

Substances

  • Minerals
  • Sodium Chloride, Dietary
  • Magnesium
  • Potassium
  • Calcium