Buckle in — this is going to be a lot longer answer than you might have been expecting.
I mentioned in my last post how white rice is generally lower in oxalate than the whole grain rices like brown or red rice. This is because the oxalates in grains are generally concentrated in the parts of the grain called the germ and the bran — which are the parts that are removed when whole grain rice is made into white rice. The same is true for wheat, which is why you'll see regular white flour listed as lower oxalate than whole wheat flour.
How Wheat is Turned Into Bread
There are three parts to a grain of wheat: the bran, the germ, and the endosperm. The bran and germ are the higher oxalate parts of the grain and are usually removed during processing. If you remove the bran and the germ and use what’s left to make bread, the finished product will be lower in oxalate than if you made the bread from the whole grain. This processing method is how you end up with the enriched flour you see on the labels of food products that most white breads are made from.
Deciphering all the marketing gimmicks companies use on food labels is a whole other set of skills — they’ll write anything they legally can to try and make people feel good about the things that are going into their products. Some will market their breads as “wheat breads”, but that just means that they're made from wheat. It doesn't necessarily mean that they're made from whole wheat.
Others will advertise as multi-grain to make you think that they’ll be healthy, but multi-grain just means more than one grain, not necessarily whole grains.
Another thing you'll see is “white wheat” — and it doesn't seem like it but this one is actually made from a variety of wheat that they call “white wheat”.
As you can see, you can't really rely on what's on the front side labels of bread. There's no actual way to know exactly what’s in them until you read the ingredients list on the nutrition label on the back.
So, Can You Actually Eat Bread on a Low Oxalate Diet?
The easy answer is yes. Just look at the TLO spreadsheet and see which specific breads have been tested for their oxalate content.
But, there are a million different kinds of breads, so if you aren’t going to choose one from that list, there are a few things to consider.
How Much Oxalate Do You Want to Eat Per Day
The first thing it will depend on is how strict you are being with your oxalate intake. The lowest oxalate breads will be made without whole grains, which isn't the best news for general health, since whole grains are considered to be more healthy.
But this is the kind of trade off you have to consider when you're choosing bread to try and fit into your low oxalate diet. If the only flour listed in the ingredients is wheat flour, or enriched wheat flour, then that bread will probably be lower than one that says whole wheat flour.
How Big Is Each Slice?
The next thing to consider is the size or, more accurately, the weight of a slice, which you can find on the nutrition label as well. It will say how many slices are in a serving (usually one) and then the weight of that serving size (or slice) right next to it in grams.
Some brands make very lightweight slices around 15g and others weigh around 40g per slice, so this is definitely something to watch out for. It's almost a 3x difference, so making a sandwich with two slices of bread that are 15g each versus two slices of bread that are 40g each is a difference of 50mg total (two 15g slices vs two 40g slices).
This is why bagels will usually be high in oxalate — not because the wheat that they use in them is necessarily any higher than the wheat used in regular breads, but because they're much more dense (bagels usually weigh about 90-100g each).
What Else Is In Your Bread?
If a bread has any other grains or seeds added to it, that will most likely make it higher in oxalate also. The exceptions here are flaxseed, sunflower seeds, psyllium husk, and starches like corn starch, rice, starch and potato starch. Rice flours can vary in oxalate content and most potatoes are high oxalate, but the starches made from them (which are basically extracts) are lower oxalate.
Malted barley flour is another flour that you'll see sometimes in breads. Barley is a high oxalate food but malted barley, which is germinated or sprouted, has about the same amount of oxalate as enriched flour made from wheat. So, if it's used in place of what would have otherwise been wheat flour in the bread, it shouldn't increase the amount of oxalate too much.
What About Low Oxalate, Gluten-free Breads?
As far as gluten-free breads go, starches are often the main ingredients. Most gluten-free grains are much higher in oxalates than wheat, so using them would make a high oxalate bread. But some gluten-free breads are made mostly from starches like rice starch and potato starch.
Tapioca Starch is also a common ingredient though, so be careful if you're choosing a gluten-free bread and tapioca starch is listed before any of the other ingredients — this is one of the few starches that’s high in oxalate.
The ingredients listed on food packaging are listed in order from highest amount to lowest amount by weight. So if tapioca starch is the first one, that means they use that in a higher amount than any of the other ingredients listed after it.
Those are some of the things to take into consideration when choosing a bread, but as you can see, it can be very hard to guess what category your bread will fall into. If you’d prefer not to guess, then just check the TLO list.
Low Oxalate Breads
One of the lower oxalate breads that's listed there is Pepperidge Farm’s Oatmeal bread. The first ingredient, and pretty much the only flour is the enriched wheat flour, which is the one that has the germ and bran removed.
There are also some oats in there, which are sometimes considered high oxalate — but oats are one of those things that also really depends on the type of oat and how it’s processed (if oats are parboiled, that will remove a lot of the oxalate).
This bread is one of the few that lists two slices as it's serving size, but each slice weighs 25g, which is towards the lower end. All these factors contribute to why this brand is on the lower end of total oxalate when it comes to bread. Each slice only has about 5.05 milligrams of oxalate per slice.