Remember, I am not a nutritionist. Everything I’m about to write came from my own experiences and from independent researching. If you haven’t yet read my musing about being a nutrition skeptic, I highly recommend it!
For a long time, I’ve noticed that my stomach is happier after eating overnight oats compared to stovetop oats. I had no idea why. Even when I made a larger portion of overnight oats (they are typically smaller in volume than the same measurement of dry oats on the stove), it would still leave me with a happier gut.
When Giselle submitted her guest post for the Spiced Plantain Brownie Baked Oatmeal, she included an instruction to soak the oats in an acidic liquid overnight. Curious, I emailed back to ask why. She responded, “Soaking the oatmeal (or any other whole grain) in acidic liquid is supposed to break down the phytic acid to make them more nutritious and digestible. Rinsing them removes most of the lemon flavor.”
Normally, hearing something like “break down the phytic acid” would set off my BS radar. ? I take being a nutrition skeptic very seriously, and I think there is a lot of nonsense being thrown around. But considering the very real, noticeable difference in my digestion after eating overnight oats vs. stovetop oats, I was intrigued.
Googling “soaking oats” brings up pages of results. Here’s what people are saying:
- “Seeds are meant to pass through the system relatively undigested so they can be planted elsewhere (think in nature). ‘Soaking’ whole grains can make them more digestible and help your system obtain all the nutrients in the food.” – Kitchen Stewardship
- “Nuts have phytic acid. Phytic acid is also found in grains and legumes. Just as with nuts, soaking grains and legumes is essential for proper digestions. When eating grains and legumes that haven’t been soaked, the phytic acid binds to minerals in the gastrointestinal tract and can not be absorbed in the intestine and to many bound minerals can lead to mineral deficiencies.” – Whole Lifestyle Nutrition
- “Soaking oats used to be par for the course in oatmeal instructions, but in the 1920s, convenience began to trump tradition (and flavor). As the demand for quick-cooking oats grew, the soaking step was eventually removed.” – Tasting Table
- “Their starches break down which improves digestibility and their natural phytic acid (which all plants contain) is greatly reduced that makes them more easily absorbed by your body.” – One Green Planet
So was I–a devout nutrition skeptic–going to put my faith in this theory? I decided to seek more scholarly sources. As an NYU student with access to online journal databases, this was an easy task for me.
According to Raj Kishor Gupta, “Monogastric animals” (i.e. creatures with a single stomach) “including poultry and humans are unable to metabolize phytic acid due to the lack of sufficient level of phytate degrading enzymes activity in their digestive tract and it is largely excreted in their manure” (2015, p. 677). In other words, our bodies don’t have enough enzymes to break down the nutrients in this food, so all that good stuff just ends up in the toilet. Oops!
And what nutrients are we “passing” on (haha)? According to Gupta, phytic acid “inhibits absorption of iron, zinc, calcium, magnesium and manganese. Removal of phytic acid increases bioavailability of many cations and thus nutritional value of meal” (2015, p. 678).
Indeed, Gupta reports that “complete submergence of grains in water” did reduce the phytic acid in sorghum flour by as much as 21%. When soaking pearl millet, it increased the “vitro solubility of iron and zinc” by as much as 23 % (2015, p. 678).
Okay, so this appears to be a real thing. I’m pretty convinced. Having only soaked my oats in water or nut milk (not an acid), I decided to try the acidic approach.
Every blog post I cited above gave me different instructions for how to do this (one even instructed me to soak it for a full 24 hours! Not happening…), so I kind of just winged it. I covered 1/4 cup quick cook steel cut oats with lukewarm water with an unmeasured splash of lemon juice. I left it on the counter at room temperature overnight.
In the morning, I ran it through my nut milk bag and rinsed it. Then, I cooked it on the stove with cashew milk and turned it into Cardamom Fudge Oatmeal. Nummmmmy.
At first, it seemed the same: both texture and flavor-wise (no, I couldn’t taste lemon). The process of soaking and then cooking resulted in a volume equal to what you would get with stovetop oats (as opposed to the smaller volume of overnight, refrigerator oats). Upon finishing, I had the same feeling of fullness that I usually get at the end of a bowl. For a few minutes, I decided this was the quackery I had expected it to be.
That changed about 30 minutes later. Typically, that is when an uncomfortable cramping starts to set in, like the oatmeal is stuck in my intestines or something. With these soaked oats, that feeling was significantly lighter than usual, and–to my surprise–I actually got my appetite back within a couple hours. This might sound obvious to the average person, but as someone with GI issues, proper digestion has not always come easy for me. This was a particularly impressive feat considering I had been experiencing tummy troubles all week.
The next day, I tried it with apple cider vinegar. I hate the flavor of this stuff (yes, even the good brands), but considering I couldn’t taste any lemon in the previous day’s breakfast, I felt confident. Sure enough, I could not detect any apple cider vinegar flavor. Yay!
Sadly, my digestion on this second day was more typical for me (i.e. not good). After an hour, I still felt quite a bit of cramping. ? Perhaps I am still getting more of these elusive micronutrients, but in terms of how I am physically experiencing the digestion, it was just as unpleasant as usual. I seem to have trouble dealing with all this fiber or something. Hooray, IBS!
Granted, this was only a two-part trial, and the effects on either day could have stemmed from a number of factors beyond soaking. (For one, I did this experiment while PMSing, so . . .?) I look forward to continuing this experiment, and if you try it yourself, let me know how it worked for you!