A niche group of food bloggers have been buzzing about the content of phytic acid in oatmeal and the implications for their favorite breakfast porridge. Having started the rumor myself here at the Rebuild site, I thought I would speak up on the issue a little more clearly.
My book Rebuild from Depression on nutrients and depression has several food science chapters focused on increasing depression-fighting nutrients in your diet through high-nutrient food choices and through preparation techniques that maximize your body’s absorption of nutrients. A book sample available online as a PDF discusses phytic acid in oatmeal and soaking grains in general. After spending many hours reading about phytic acid only to include a few pages on it in a book, I developed an e-course here on this site in 2006 which ended up with thousands of subscribers. The course is now defunct until I have time to do something with it, though the more extensive and easier-to-read Phytic Acid White Paper is available for purchase.
In any case, thousands of e-course graduates have started alarming people about oatmeal.
What’s Up With Oatmeal And Phytic Acid?
Food bloggers have taken a cue from food writer Sally Fallon in her book Nourishing Traditions and have soaked grains overnight in warm water with a dash of whey or yogurt in order to reduce the phytic acid content in the grains. Phytic acid does, indeed, inhibit your absorption of minerals (calcium, zinc, iron, and magnesium to name a few).
The soaking strategy does work to reduce the phytic acid because it activates the phytase enzyme in the grain to break down the phytic acid. The phytic acid disappears like a traditional foods miracle and you get more minerals out of your food. The problem with oatmeal is that it lacks sufficient quantities of phytase. Soaking it will make it cook faster and that is a great thing on a busy weekday morning, but the soaking does not help from a phytic acid perspective.
How do I know?
The food science literature on phytic acid is voluminous — only bits were captured in the 20-part e-course and in the 40+ page paper. Below is a graphic display of a study from the food science literature comparing the reduction of phytic acid in various grains. Notice that the phytic acid content of wheat, rye, and barley decrease rapidly with soaking. It is apparently the same with buckwheat, kamut and spelt; I have limited information on quinoa, teff, and amaranth. Phytic acid in oats and corn decreases very little over the same 12-hour period. These grains are both noted exceptions in the food science literature. Millet and brown rice are similar as well. It is not as if a 13th hour of soaking would have made a big difference. Soaking simply is not effective with every high-phytic acid food. (Soy milk and phytic acid is a good example.)
What to do?
It seems a drastic measure to stop eating oatmeal. That would be tragic. As it turns out, food science offers a solution.
(1) Complementary soaking
Taking the lead from another phytic acid study, I have recommended in the now-defunct e-course to add a bit of fresh ground wheat, spelt, rye, or buckwheat to the oatmeal and then soaking it. The phytase in these other grains will work to reduce the phytic acid in the oats. I have recommended using about 10% of the complementary fresh ground grain to 90% oatmeal, though often I add a heaping tablespoon to a cup or so of rolled oats. Soak the oatmeal in water above body temperature overnight in a warm spot. Use the same amount of water you usually cook it in and simply throw it all in the pan in the morning. I do not recommend using the yogurt or whey anymore, just stick with the complementary grain for more diligence.
To make this task easy, buy a coffee grinder that you can dedicate to grinding small amount of grain on demand. If you have to power up an actual grain mill, you have added far to much work to your oatmeal. Try to keep your spouse or roommate from using it as a coffee mill.
I have gotten questions about how I know exactly how much complementary grain to add. Research suggests it should be about 10% of the total but there are no oatmeal experiments to test this recommendation explicitly. You can add more if you don’t find that it changes the flavor of the oatmeal. You can add less (which will still help). If you eat large quantities of oatmeal and rely on it for nutrition, perhaps you do want to add another tablespoon.
(2) Don’t worry about it.
This strategy is a much-forgotten one and a good one to keep in mind for kitchen survival. I just ate unsoaked oatmeal this morning for the first time in quite a while and I have to admit that it was fantastic. Had I soaked it, it would have cooked in a few minutes of course. The cook time always gives me an added incentive to soak oatmeal but when the household insists on oatmeal and it is not soaked, I typically make it anyway.
You will never reduce the phytic acid in beans or nuts to zero and they are pretty good foods. You can put oatmeal in the same category.
If you find yourself worrying about the oatmeal as you eat it (soaked or unsoaked) perhaps you should seek out another grain. Worry and stress actually increase our body’s need for nutrients. @AustenFanatic on Twitter recommends buckwheat.
If you are going to bite the bullet and embrace the oatmeal, here are some soaked oatmeal recipes from traditional foods bloggers who do the complementary soaking: