Effect of sodium phytate supplementation on fat digestion and cholesterol metabolism in female rats

Abstract

The effects of sodium phytate supplementation on fat digestion and cholesterol metabolism were investigated in female rats. On the basis of an in vitro experiment showing that phytate raised the solubility of bile acids, it was predicted that phytate feeding would depress faecal bile acid excretion, raise apparent fat digestibility and elevate serum cholesterol concentrations. The experimental diets with or without sodium phytate were either cholesterol-free or cholesterol-rich and had a normal calcium concentration. Rats fed on the cholesterol-rich diet with sodium phytate showed enhanced faecal bile acid excretion, but there was no effect on fat digestibility. In rats fed the cholesterol-free diets, phytate did neither affect fat digestion nor bile acid excretion. Sodium phytate inclusion in the cholesterol-rich diet raised serum cholesterol concentrations, but reduced liver cholesterol concentration. Thus, the in vivo data do not agree with the in vitro observations. Both phytate and cholesterol feeding influenced mineral and trace element metabolism. Liver zinc concentrations were raised by phytate feeding. Cholesterol consumption reduced hepatic concentrations of copper, iron and zinc. Both phytate and cholesterol feeding reduced the apparent absorption of calcium, magnesium and phosphorus.

The Potential Benefits and Adverse Effects of Phytic Acid Supplement in Streptozotocin-Induced Diabetic Rats

“…The observed decrease in hepatic lipogenic enzyme activities in this study may also be explained by Yuangklang et al [30] report that calcium-phytate complex does not bind bile acids which suggests maintenance of bile acids pool and nonutilization of cholesterol for bile acid synthesis with subsequent elevation in serum cholesterol.…”

“…The elevated cholesterol noted in our study may be attributed to the use of calcium-magnesium phytate rather than sodium phytate used in other studies. In an in vitro study carried out by Yuangklang et al [30], calcium phytate complex was shown not to bind bile acids. They also suggested that this may reduce fecal bile excretion and increase serum cholesterol in vivo.…”

Review: Anti-nutritional effects of phytic acid in diets for pigs and poultry – current knowledge and directions for future research

“…In their study, the apparent absorption of total lipid and cholesterol was also reduced, whereas fecal cholesterol and lipid contents were increased by the dietary phytic acid. Yuangklang et al (2005) also reported increased excretion of bile acids in feces and reduced concentration of cholesterol in the liver of rats fed a cholesterol rich diet by 28 and 22%, respectively, due to an increase in dietary phytic acid concentration from 0 to 0.33%. However, the increased fecal excretion of bile acids did not translate to reduced fat digestibility and serum cholesterol concentration and the reason for this is not clear.…”

Effects of dietary phytic acid on digestibility of main nutrients and mineral absorption in mink (<i>Mustela vison</i>)

“…Moreover, in vivo trials have shown that the trypsin activity does not necessarily conform with protein digestibility (Sajjadi and Carter, 2004). Likewise, Yuangklang et al (2005) concluded from a study where sodium phytate had an effect on bile acids in vitro, that there was no relationship with in vivo lipid digestibility in rats. The use of different protein sources in different studies may also explain contradictory effects of IP6 on utilization of main nutrients (Kies et al, 2006) The solubility profile of protein from different sources such as soya, canola, sunflower and maize vary with pH levels, and the presence of IP6 has a significant effect on the solubility of protein.…”