Cacao is now treated as one of the very healthy food items. It is high in polyphenol and iron. In fact, pure cocoa powder without any cocoa fat, milk, or sugar, provides the most iron with 36mg in a 100g serving, or 200% of the RDA. That is 1.8mg of iron per tablespoon of cocao powder, or 10% of the RDA. Unsweetened baking chocolate provides 17.4mg per 100g (97% RDA), or 23mg (128% RDA) per grated cup. Most sweetened milk chocolates will provide around 2.4mg per 100g (13% RDA), or 1mg (6% RDA) of iron in an average 1.5 ounce bar.
However, Katherine Zeratsky, R.D., L.D. wrote an article on the Mayo Clinic website saying that, “Chocolate contains oxalate — a naturally occurring compound in cocoa beans — which can inhibit the absorption of calcium. Calcium binds to oxalate in your intestines, limiting its absorption into your bloodstream. People with oxalate kidney stones, which could occur when there is too much oxalate in the urine, should limit the amount of oxalate in their diets.
A 2008 study found that elderly women who ate one or more servings of chocolate a day had lower bone density and strength than did women who ate fewer servings of chocolate. Researchers believe this may be due to oxalate inhibiting calcium absorption — but it could also be due to the chocolate’s sugar content, which may increase calcium excretion.”
Oxalates are also found in spinach, kale, beets, nuts, chocolate, tea, wheat bran, rhubarb, strawberries and herbs such as oregano, basil, and parsley. They are inhibitor foods for iron absorption too. The presence of oxalates in spinach explains why the iron in spinach is not absorbed. In fact, it is reported that the iron from spinach that does get absorbed is probably from the minute particles of sand or dirt clinging to the plant rather than the iron contained in the plant.
The polyphenol in cacao is also a major inhibitor of iron absorption. The Iron Disorder Institution says on their website: “Polyphenols are major inhibitors of iron absorption. Polyphenols or phenolic compounds include chlorogenic acid found in cocoa, coffee and some herbs. Phenolic acid found in apples, peppermint and some herbal teas, and tannins found in black teas, coffee, cocoa, spices, walnuts, fruits such as apples, blackberries, raspberries and blueberries all have the ability to inhibit iron absorption. Of the polyphenols, Swedish cocoa and certain teas demonstrate the most powerful iron absorption inhibiting capabilities, in some cases up to 90%. Coffee is high in tannin and chlorogenic acid; one cup of certain types of coffee can inhibit iron absorption by as much as 60%. These foods or substance should not be consumed within two hours prior to and following your main iron-rich meal”
So, you can indulge yourself with Chocolate but think about the timing and quantity. Select high quality organic one if you want.