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Table 1 The proposed interplay between osmotic loads in the upper digestive tube and sodium and fluid sparing actions imposed on kidneys and large bowel by increased ADH and aldosterone secretion due to a transitory decline in the circulatory volume

From: Arterial hypertension due to fructose ingestion: model based on intermittent osmotic fluid trapping in the small bowel

Beverage Content & overall osmolarity Fluid cycle Secretion
(V = 0.5L) (O) Theoretic values Fluid absorption in hours Aldosterone ADH
   Initial trapped volume Vd= V*O/300-V Total volume for absorption V>a= Vd+V < 2 h with < = 4 h   
Salty commercial soup 1.3% NaCl, 400 mosm/L ~ 0.16 L ~ 0.66 L ~ 0.66 L none blocked by sodium absorption increased by reduction in circulatory volume
Sucrose soft drink 13.3% sucrose, 400 mosm/L ~ 0.16 L ~ 0.66 L ~ 0.33 L with glucose ~ 0.33 L with fructose weak and transitory increase in secretion due to small initially trapped volume
HFCS soft drink glucose 360, fructose 440, overall 800 mosm/L ~ 0.83 L ~ 1.33 L ~ 0.6 L with glucose ~ 0.73 L with fructose increased secretion due to slow fructose absorption results in sodium & volume sparing in kidneys and large bowel
WHO peroral rehydrattation solution glucose 75, salt 170, overall 245 mosm/L none 0.5 L near 0.5L almost none rehydration without fluid trapping, hormone secretion is reduced
  1. Soft drinks with high fructose corn sirup (HFCS) are so hyperosmolar that they trap large volumes of intestinal fluid until their sugars are absorbed (Fig. 1.). Absorption takes longer for fructose [1315]. Other liquids are moderately hypertonic and their influences on fluid and sodium homeostasis are much weaker. The WHO recomended solution for rehydratiopn is hypotonic so no fluid is being trapped in the small bowell.