The American Chemical Society have devised an intestinal cell line to measure how much iron is being absorbed through the membrane of the gut.. We ourselves have used such a cell line to measure the effect of a plant compound on gastric ulcers and found the results to be accurate, when using the calculated cell line dosage in vitro. In other words, the cell line helped to find out the effective dosage before testing with gastroscopy. This system is used to test mineral uptake in baby milk preparations and is used extensively to compare bioavailability of iron supplements.
This cell line was used to check for the inhibition of iron uptake by gallic acid (wild blueberries, bark of trees) polyphenols and tannins, (yarrow, thyme, oak, oregano, willow), chlorogenic acid (blueberries, parsley). The results were as follows 5 mg of tannic acid inhibited iron uptake by 20%, 25 mg by 67% and 100mg by 88%, gallic acid inhibited iron uptake by the same amount whilst chlorogenic acid was much lower.
Don’t worry if you don’t have too much iron in the diet, plants also contain ascorbic acid, this chemical helps to colour flowers and berries, bryophytes are also high in ascorbic acid. Ascorbic acid reduces the inhibition of iron by gallic acid, polyphenols and tannins. As usual nature has its system of health, it’s called biodiversity, instead of trying to micro manage the mineral intake, have some fun, plant some herbs, forbs and hedges and increase natures abundant supply of dietary goodness!
References supplied on request