Recently by Mark Sisson: Does Eating Red Meat Increase Type 2 Diabetes Risk?
You know how we say that grains exist on a spectrum of suitability, from “really bad” wheat to “not so terrible” rice? Well, what about the rest of ’em? They may be the most commonly consumed (and thus encountered) grains, but wheat and rice aren’t the only grains on the spectrum. Since I get a lot of email about oats, I figured they were a good choice for this post. Besides — though I was (and still mostly am) content to toss the lot of them on the “do not eat” pile, I think we’re better served by more nuanced positions regarding grains. Hence, my rice post. Hence, my post on traditionally prepared grains. And hence, today’s post on oats. Not everyone can avoid all grains at all times, and not everyone wants to avoid all grains at all times. For those situations, it makes sense to have a game plan, a way to “rank” foods.
Today, we’ll go over the various incarnations of the oat, along with any potential nutritional upsides or downsides. But first, what is an oat?
The common oat is a cereal grain, the seed of a species of grass called Avena sativa. Its ancient ancestor, Avena sterilis, was native to the Fertile Crescent in the Near East, but domesticated oats do best in cool, moist climates like regions of Europe and the United States. They first appeared in Swiss caves dated to the Bronze Age, and they remain a staple food crop in Scotland. The “whole grain” form of an oat is called a groat (the picture up above depicts whole oat groats) and is rarely sold as-is, except maybe as horse feed. Instead, they’re sold either as steel-cut, rolled, or instant oats.
Steel-cut oats are whole groats chopped into several pieces. Some of the bran flakes off, but some is retained. Steel-cut oats take longer to cook, contain the most nutrients (and antinutrients like phytic acid), and taste nuttier than conventional oats.
Rolled oats are steamed groats that have literally been rolled out and flattened, with the bran discarded. When most people think of “oats,” they’re thinking of rolled oats.
Instant oats are rolled, steamed, and precooked oats. They’re essentially the same as rolled oats, only often accompanied by sugary flavorings and rendered immediately edible by the addition of hot liquid.
The main problems with oats are the phytic acid and the avenin, a protein in the prolamine family (along with gluten from wheat, rye, and barley, and zein, from corn). As far as phytic acid (or phytate) goes, oats contain less than corn and brown rice but about the same amount as wheat. As you know from previous posts, phytate has the tendency to bind minerals and prevent their absorption. So, even if a grain is rich in minerals, the presence of phytate prevents their full absorption. Ingestion is not absorption, remember. As I understand it, you can, however, reduce or eliminate phytate by lactic fermentation. I’m not sure the degree to which phytate can be deactivated, but one study does show that consuming oats that underwent lactic fermentation resulted in increased iron absorption rather than reduced. Another source claims that simple soaking isn’t enough, since oats contain no phytase, which breaks down phytate. Instead, you’d have to incorporate a phytase-containing flour to do the work; a couple tablespoons of buckwheat appear to be an effective choice for that. Combining both lactic acid bacteria (whey, kefir, or yogurt), companion flour (buckwheat), water, and a warm room should take care of most of the phytate… but that’s a lot of work!
Avenin appears to have some of the same problems as gluten in certain sensitive individuals, although it doesn’t appear as if the problem is widespread or as serious. Kids with celiac disease produced oat avenin antibodies at a higher rate than kids without celiac, but neither group was on a gluten-free diet. When you put celiacs on a gluten-free diet, they don’t appear to show higher levels of avenin antibodies. It looks like once you remove gluten, other, potentially damaging proteins become far less dangerous. One study did find that some celiacs “failed” an oats challenge. Celiac patients ate certified gluten-free oats (quick note: oats are often cross-contaminated with gluten, so if you’re going to experiment with oats, make sure they’re certified gluten-free), and several showed signs of intestinal permeability, with one patient suffering all-out villous atrophy, or breakdown of the intestinal villi. A few out of nineteen patients doesn’t sound too bad, but it shows that there’s a potential for cross-reactivity.