First, let's have a quick rundown of what it is exactly that compose grains:
Phytic acid: Phytic acid is the main storage form of phosphorus in grains. That’s awesome for the grain, which needs phosphorus, but there’s a catch. Phytate also binds to many minerals, including zinc, magnesium, calcium, and iron, to name several. And, since non-ruminants don’t possess phytase, which digests phytate and releases the bound minerals for easy absorption, eating large quantities of phytate-containing foods results in mineral deficiencies for meat-eating apes. These deficiencies, taken to an extreme, can manifest as tooth decay, which might explain why early grain eating populations had worse teeth than the hunter-gatherers who preceded them.
Enzyme inhibitors: Grains are seeds that require certain wet, nutrient rich conditions for proper growth. Spontaneous germination is counterproductive (you don’t want your children settling down in an area with high crime and high unemployment, do you?), so enzyme inhibitors prevent it. When moisture abounds (like, when soaking grains), the inhibitors are deactivated and sprouting occurs. So why should we care? Certain other enzyme inhibitors also inhibit our ability digest the grains. If you’re relying on grains as a dietary staple, you can’t afford not to wring every last drop of nutrition out of them.
Lectins: I covered lectins fairly comprehensively in a previous post, so I’ll keep it brief. Lectins are nature’s pesticides, protecting the tiny grain from predation. They can perforate the intestinal lining, disrupt our immune systems, and there’s even evidence that they bind to leptin receptors in the hypothalamus (potentially triggering leptin resistance).
Gluten: You know this guy. Found in wheat, rye, and barley, he’s a real bastard of a protein – and possibly not just to celiacs. There’s some evidence that true fermentation can break down gluten, but not all of it. Some Italian researchers used a unique blend of bacterial species to break down 99% of the gluten in sourdough bread, but it was under strict, extremely contrived laboratory conditions. More on that later.
How do these traditional cultures manage to eat grains then?
Soaking and Sprouting
I’ve written about soaking nuts and seeds before, and soaking grains is the same idea. The grains are covered with water, placed in a preferably warm place, and soaked for between 12 and 24 hours. There’s not much more to it than that. After soaking, you drain them, rinse them, and let the grains sit out for a couple days. To get grains to sprout, rinse and drain them a couple times each day until sprouts emerge.
Effect on phytate: If the grain contains phytase, some of the mineral-binding phytic acid will be deactivated, but not much. And if the grain has been heat-treated, which destroys phytase, or it contains very little phytase to begin with, the phytic acid will remain completely intact. Overall, neither soaking nor sprouting deactivates a significant amount of phytate.
Effect on enzyme inhibitors: Well, since the seed has been placed in a wet medium and allowed to sprout, the enzyme inhibitors are obviously mostly deactivated. Digestion is much improved (cooking will improve it further).
Effect on lectins: The evidence is mixed, and it seems to depend on the grain. Sprouted wheat, for example, is extremely high in WGA, the infamous wheat lectin. As the wheat grain germinates, the WGA is retained in the sprout and is dispersed throughout the finished plant. In other grains, sprouting seems more beneficial, but there’s always some residual lectins that may need further processing to deactivate.
Effect on gluten:Sprouting reduces gluten to some extent, but not by very much. Don’t count on it. A little bit goes a long way.
After soaking and grinding, grains are traditionally mixed with a starter culture or allowed to wild ferment. Starter cultures often include whey, kefir, yogurt, or left over fermentation medium from the previous batch. Wild fermentation occurs when the grain mixture employs bacteria already present on the grains, or picks up wild yeasts and bacteria from the environment. Both methods are far more effective than just soaking and sprouting at deactivating antinutrients and improving digestibility. Plus, fermentation lends interesting flavors to and enhances the shelf-life of the resultant food (which was extremely valuable in the days before refrigeration and canning).
Effect on phytate: Remember phytase? It’s the enzyme that deactivates phytate, and it really gets cooking during fermentation. In grains that contain high amounts of phytase, like wheat, rye, and buckwheat (technically a pseudo-cereal, but close enough), a day of fermentation deactivates most of the phytate. To degrade the phytate in low-phytase grains, however, the fermentation time must be extended. Adding small amounts of phytase-containing grain to the mix will also speed up the process. Increasing the temperature also improves phytate breakdown. In millet, a low-phytase grain, it took 72 hours to completely degrade the phytate. In wheat, it took ten hours to reach a maximum of 88.8% phytate reduction using a specific bacterial strain. Other strains resulted in reductions of between 28% and 86% (with most reaching above 80%). Standard quick rise baker’s yeast only reduced 16% of phytate (that’s what 99% of wheat eaters are eating nowadays, remember!). Ten hours may not always be enough, however – another fermentation study found that at 48 hours, phytate in wheat was still degrading.
Effect on enzyme inhibitors: Fermentation also significantly reduces enzyme inhibitor activity. A few examples would be prudent, since fermentation has different effects on different enzyme inhibitors in different grains. In 24 hour traditional sorghum fermentation, both trypsin inhibitor and amylase inhibitor (which impedes starch digestion) were reduced by up to 58% and 75%, respectively. In millet, a 48 hour fermentation was required to completely deactivate amylase inhibitor. As I mentioned in the last section, one study found that 48 hours of fermentation resulted in maximum wheat starch digestibility, presumably by deactivating amylase inhibitor.
Effect on lectins: Fermentation reduces lectin load fairly comprehensively across the board, but it might take longer than you can spare. In lentils (I know, not a grain, but with similar antinutrient issues), 72 and 96 hours of fermentation at 42 degrees C eliminated 98% and 97.8% of the lectins, respectively. Specific info on grain lectin breakdown due to fermentation is sparse. Overall, fermentation appears to be pretty effective at reducing lectins (and cooking reduces them further).
Effect on gluten: No store bought garden variety sourdough you find is going to be gluten-free. A team from Italy was able to produce a gluten-free sourdough wheat breadby using specific bacterial strains from all over the world and subjecting the bread to many days of fermentation. The process was totally unfeasible for the home or average commercial baker. There’s also a guy who sells monthlong fermented sourdough bread out of LA-area farmers’ markets and claims celiacs can eat it without issue. Reviews on Yelp seem to corroborate. Maybe I’ll swing by his stand and give it a shot, but I’m skeptical. And besides, I’m personally more worried by WGA, which is biologically active at nanomolar concentrations and which may not be fully degraded by fermentation.
Mark's take on it:
That said, will I start soaking, sprouting, and fermenting big batches of grains in my kitchen? No. It’s way too much work and it’s unclear whether the toxins are fully mitigated (and in the case of wheat, they almost certainly are not). I’ll admit that crusty sourdough bread can be a nice occasional treat when eating out, but it’s not something I’m interested in eating on a regular basis. Furthermore, I’m not missing out on any magic nutrient by avoiding grains, but I am avoiding the elaborate prep work required to make them moderately edible (and the toxins that may or may not be deactivated). For the billions that rely on grains for sustenance, these traditional preparation methods are necessary. Choosing between potentially toxic food and starvation, you choose the food – no question – and then you do your best to make it more nutritious. For those of us who don’t need to make that choice, for whom bread is an extracurricular treat, I think removing the risk altogether by simply avoiding the potentially toxic food is a better move. And if it’s carbohydrate you’re after, stick with safe starch sources like roots, tubers, or even white rice (the sole grain that requires no elaborate processing).