Grains, legumes, nuts and seeds contain enzyme inhibitors to keep them from sprouting. They contain phytic acid (storage form of phosphorus, also known as phytates) which can block the absorption of minerals (particularly zinc, iron and calcium) by binding to them (for an extensive list of studies on the topic and for a more in-depth article, please read this). A moderate intake of phytic acid has been shown to reduce your risks of cancer, but too much of it can impede the body’s ability to absorb nutrients. Phytates play an important role in plants; they give seeds the energy needed to sprout since the enzyme phytase will break down the stored phytates during the sprouting process. Everyone who eats plants consumes phytic acid.
Several methods have been developed to reduce the phytic acid content in food:
1- The most common one is milling. Unfortunately, it also removes an important a major part of minerals and fibre and it should be done at low temperature to preserve the phytase.
2- Pretreatment methods such as soaking and germinating are also widely applied and have shown some effectiveness. Soaking them starts the germination process and causes the protease inhibitors (molecules that inhibit digestion) to leach into the water. The soaking process is accomplished with enough room temperature water to cover the nuts, seeds or grains and about 1 tablespoon of lemon juice or vinegar or salt in the case of nuts. The soaking time varies depending on the type of nut, seed or grain, but is generally between 8 and 12 hours.
3- Fermentating grains increases the bioavailability of minerals by providing the right pH for the enzymatic degradation of phytates. Natural fermentation of millet and rice has shown to reduce the amount of phytic acid. Fermentation is a step further than soaking. The soaked grains are left at room temperature for days in liquid and a starter (liquid from a previously fermented batch).
4- Germinating has been shown to reduce the phytic acid content by up to 40%. To germinate, drain the water after the soaking and let the grains sit at room temperature for a few days, rinsing them twice a day.
5- Roasting and cooking disactivates the protease inhibitors.
A combination of methods involving particularly fermentation seems most effective. Germinating or fermenting AND cooking will yield the best results.
All that being said, these ideas about the preparation of beans, grains and legumes are largely propagated through the work of the Weston Price Foundation and the claim that traditional cultures prepare them in some way before consuming them. I was wondering if the care taken by traditional cultures to process their grains was overstated. I did some research and found that it is quite real. This page was particularly interesting.
However, some people argue that:
1- Uness one lives in a Third World country, worrying about mineral deficiencies is a waste of time. Only zinc might be low in vegetarian diets and a good supplement will cure that problem.
2- Phytate is actually beneficial to the body as a powerful antioxidant and should not be avoided.
Studies and scientific data are often misleading and used to support different conclusions. The purpose of this blog is to look at the information available and test it through practical means. In this case, this would mean ingesting grains and nuts without preparing them and after preparing them to find out if it makes a difference. I read about people who had noticed a difference, so I know in some cases it is helpful. I believe for me, a combination of both will be optimal.