Most people are surprised when they first hear that a white bread has more of a sugar hit than sugar itself! Fluffy, soft white bread made with finely processed flour has long been considered a delicacy, and certainly tastes great! Unfortunately, it is very high GI – in the order of 70-100 depending on how it is processed, cooked, and how fresh it is, and also influenced by what it is eaten with. Finding yourself a good sourdough bakery that uses wholegrain flours is half the battle! We love morpeth sourdough bread, and recently we found a wonderful sourdough bakery in Melbourne – their bread is pictured above! The bakery is called Knead Bakers, in Burwood Road, Hawthorn. If you know any great sourdough bakeries, let us know and we will link them here for our other readers!
If you go to the GI data tables published by the Sydney University site dedicated to GI, glycemicindex.com and type bread, you will come up with a list of breads which have been tested for GI. When going through these tables, I have summarised for you what I take as the main principles in choosing bread that is lower GI. Remember, just because a fluffy white loaf has the label “sourdough” does not mean it is low GI. It may have a very small amount of sourdough added. Look for breads with a GI symbol on them, or follow the following principles:
Denser bread (less air, more substance) will feel heavier when you hold it. If you tap the side of a loaf, it will also make a sound more like a “thud” (more solid). If you are buying it, feel it’s weight, and leave it on the shelf if it feels like a light, fluffy loaf. If you make your own bread, consider the following values published on the GI website:
White bread, prepared with a 10 min prove and a second 2 min proving (low loaf volume)
White bread, prepared with a 30 min prove and a second 12 min proving (moderate loaf volume)
White bread, prepared with a 60 min prove and a second 30 min proving (moderate loaf volume)
White bread, prepared with a 40 min prove, a second 25 min proving and a third 50 min proving (large loaf volume) -GI:100, GL:13
Source: GI database, http://www.glycemicindex.com
It is clear that the longer the yeast is allowed to take effect prior to cooking, or the higher the loaf rises, the higher the GI value will be! My guess is that the science behind this involves the yeast spreading out, taking effect, and doing its work to make the bread easier for us to digest. Following these principles, un-leaven bread should also be lower in GI value.
Rye and barley breads have lower GI values than plain wheat bread, as do breads with seeds added, such as oat flakes, soy and linseed, and multigrain varieties. Stoneground wholewheat flour breads are also lower GI. The principle here to understand is that the more fibrous chunks there are in the bread (such as the larger, coarser grains of stoneground flour), the more work the body has to do to break down and access the starches.
Pumpernickel rye bread with coarse rye kernels has a particularly low GI of 41 with a GL of 5.
As well as grains, sourdough is the most well known additive to lower GI. Sourdough wheat bread has variable GI values, depending on other factors, but seems on average a GI value around 50-60, and a GL value of around 7-8.
People have also added other things to bread to see the effect on GI, such as insoluble fibre, or enzyme inhibitors. These both lower the GI quite significantly. Here an example of what happens to GI when fibre is added in the form of beans:
White bread with 3 g Sunfibre (Cyamoposis tetragonolobus) (Indian cluster guar beans), viscosity 1 (Taiyo Kagaku Co., Ltd, Yokaichi Mie, Japan) GI:53 GL:8
White bread with 5 g Sunfibre (Cyamoposis tetragonolobus) (Indian cluster guar beans), viscosity 1 (Taiyo Kagaku Co., Ltd, Yokaichi Mie, Japan) GI:49, GL:8
White bread with 10 g Sunfibre (Cyamoposis tetragonolobus) (Indian cluster guar beans), viscosity 1 (Taiyo Kagaku Co., Ltd, Yokaichi Mie, Japan) GI:47, GL:8
White bread with 15 g Sunfibre (Cyamoposis tetragonolobus) (Indian cluster guar beans), viscosity 1 (Taiyo Kagaku Co., Ltd, Yokaichi Mie, Japan) GI:37, GL:6
Source: GI database, http://www.glycemicindex.com
One of the interesting values I noticed among the various GI values for bread published was a comparison between barley bread made with 70% barley flour and 40% wheat flour cooked at different rates. The same bread mix had a lower GI when baked more slowly and at a low temperature. GI:70/GL:9 compared to GI:49/GL:6
What it is eaten with
The artificial thing about knowing the GI values of bread is that we don’t just eat bread, we eat it with things, usually in the form of sandwiches. Interestingly, an almond manufacturer measured the effect of consuming various amounts of almonds along with white bread. The GI values were dramatically reduced by consuming more almonds with the bread. If 60g of almonds was eaten, GI value dropped to 44, GL 23, whereas if 30g of almonds were eaten, GI value was 74, GL 37.
There is no need to be obsessional, overall, choose a heavier, denser loaf, multigrain or sourdough, and eat it with low GI foods. Have a lovely salad sandwich, and follow it with a handful of almonds, and you’ll know you are on the right track!!