Monday, 3 November 2014

Phytic acid and mineral absorption

Seeds, grains and nuts store Phosphorous (P) in an organic compound called
phytic acid (or phytate in its salt form). Phytic acid has a strong ability to bind with multivalent metal ions, such as iron, zinc and calcium. This binding reduces the bioavailability (absorption) of these minerals. Humans lack the digestive enzyme, phytase, which is required to break down the undigestible phytic acids and release the digestible phosphorus, calcium and other nutrients (Mittal et al, 2013).

Decreasing phytic acid or including the enzyme phytase increases the absorption of iron, zinc, magnesium and calcium (Coulibaly et al, 2011).

% of Phytic Acid in food (Screenshot from Wikipedia)

Neutralising phytic acid to increase mineral absorption
  • Soaking of cereals and grains overnight.
  • Cooking. Heat can destory small amounts of phytic acid but can also destroy vitamin C.
  • Germination/Sproting. 6 to 10 days of germination showed an increase in mineral uptake.
  • Malting, a process where the whole grain is soaked then germinated.
  • Fermentation. Major fermentation microorganisms include lactic acid bacteria, moulds and yeast. More on this point below.

Creating the enzyme, Phytase
Tempeh, miso, koji and soy sauce are the products of fermenting soybeans with Aspergillus oryzae and this has shown to produce phytase (Fujita et al, 2003).
Sumengen et al (2012) presents their results with the production of phytase from Lactobacillus brevis, a well-known lactic acid bacteria found in yogurt. Similar findings are found with bifidobacteria to reduce phytate (Sanz-Penella et al, 2009).

Grains, oats and seeds contain phytic acid that reduce the absorption of minerals (iron, calcium, magnesium, zinc). The enzyme, phytase, is required to breakdown the compound. Phytase can be produced with lactobacilli and bifidobacteria.

To increase mineral absorption with your raw carbs:
  • Add a probiotic with lactobacilli and bifidobacteria.
  • Pick a multi-vitamin with phytase and/or probiotics.
  • Add yogurt!
  • DIY yogurt naturally or with kefir and create more goody bacterias. I use the freeze-dried kefir.