The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Sourdough and diabetes?

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hamletcat's picture
hamletcat

Sourdough and diabetes?

Hi, 

I have read that sourdough breads are good for diabetics.  Could someone explain why this is true, because I have a number of diabetics in my family and they don't eat bread products and my understanding is because it spikes their blood sugar.  

chris319's picture
chris319

No bread is "good" for diabetics; it's all carbohydrate. Sourdough isn't as bad as white sandwich bread, to which a lot of sugar is added.

Bakingmadtoo's picture
Bakingmadtoo

From what I have read it scores lower on the glycemic index, which means it releases its sugars more slowly. All carbohydrate in any form will affect the blood sugar and diabetics have to monitor their insulin intake to compensate for the carbohydrate that they eat. Some diabetics will take more insulin to cover the carbs, others take a stricter approach to diet to try and keep sugar levels stable. Maintaining stable sugar levels can be an extremely complex subject, and for some diabetics, even with close monitoring can be near impossible to achieve. If your family members have found a diet that keeps their blood sugars relatively stable, I would encourage them to stick with it. And certainly take medical advice before adding in carbs they are not used to to ensure that they thoroughly understand what they are doing.

hamletcat's picture
hamletcat

So it is just because you don't actually add table sugar to it, that makes it better.  Otherwise it would be just as bad for diabetics as regular white bread.

tchism's picture
tchism
dabrownman's picture
dabrownman

to 1 tsp of sugar - even those without sugar added.  What is different is that whole grain and SD bread, especially those with whole barley in them, have a lower Gi so that all the sugar doesn't hit the bloodstream at the same time causing a larger spike in blood sugar for diabetics.  Most doctors would tell diabetics to stay away from all foods high in carbs including bread - except for most veggies and some fresh fruits low in carbs.

PaddyL's picture
PaddyL

And I make and eat white sourdough bread; it does not spike my blood sugar the way regular white bread does.  It's even better if I throw some oatmeal into the dough.

hamletcat's picture
hamletcat

Do you know why?  It says that it is also made from white flour so I don't understand why regular white bread would, unless it is because of the added sugar used to activate the yeast.

dabrownman's picture
dabrownman

It has the Lowest GI, I think at 41, of any grain with gluten by far.   

adri's picture
adri

First of all, there are many different types of diabetes.

Some have to do with blood sugar (diabetes mellitus), some don't (diabetes insipidus).

The way you ask I assume you're referring to diabetes mellitus. But within this group there are still a lot. The most common one is DM type 2. Here the pancreas can produce insulin (and usually produces a lot), but the cells don't react very well and don't produce glucose transporters. Therefore the bloodglucose levels stay higher. As physical activity causes the muscle cells to absorb the glucose better this might be included in the therapy.

Also, as fat/protein have a lower GI, they need less Insulin per calories. The GI is not how fast the blood glucose rises but the surface under the curve above basal glucose level. This mostly is proportional with the rapidity of the carbs, but not always. Pure fat/protein make the blood glucose rise just a bit but need insulin for about 9 hours. The area under the curve therefore is not neglectable because of the long timespan. But because of the little rise at each point in time, the pancreas might be powerful enough to keep the bg level low. One treatment of course can be external insulin.

The second most common type is DM type 1. This is a totally different disease that unfortunately has a similar name, also has something to do with blood glucose levels and always has to be treated with insulin. In general, Insulin here works just fine. But due to an autoimmune defect, the pancreas can no longer produce insulin. This is usually treated with 5+ injections each day or with an insulin pump (a small infusion set that delivers a portion of insulin every 3 minutes). Here no diet is necessary as long as the exact contents of a meal are known. As there is no regulation from the pancreas the patient has to estimate (or usually measure) the contents of food, physical activity... and adjust the insulin intake accordingly.

... and there are a lot of more types e.g. the MODY types that are caused by single genetic mutations.

 

As you can see, for Type 1, industrially produced bread could be most healthy, as you can calculate the contents of a slice precisely up to a fraction of a gram of carbs, fat, protein, ... and take the exact amount of insulin for it.

For Type II, a whole grain sourdough bread might be most healthy as it has a lower glycemic index AND as it also has less carbs per slice definitely a lower glycemic load.

I hope this wasn't too much or too confusing information. The standard lectures for a diabetic are well above 100 hours of theory, reaching form how insulin is absorbed after subcutaneous injection, how it reacts with it's receptors on different cells in the body, how glucose transporters in cell walls work, half-life of insulin in blood and glucose transporters in cells, how other hormones/steroids interact (circadian rhythm, illness, ...)...

I'm no longer working in the medical field, but if you have any question, just ask.

hamletcat's picture
hamletcat

Your response helps so much, thanks.  GI then has more to do with how the pancreas is able to keep up with the BG, after eating something.  So with something that is easily digestible, such as a simple sugar or food containing a simple sugar, the GI would be higher?  So sourdough doesn't have added sugar, and the yeast has broken down some of the sugar already, so it has less of an impact.  White bread contains sugar, and hasn't fermented as long, so there is more starch/sugar in the food.  Also the protein/carb ratio would be higher because more have the starch has been metabolized by the yeast.  Which means the pancreas might be better equipped to keeping up with the BG if the protein takes longer to reach the blood sugar.  Is this correct?

adri's picture
adri

For type 2 diabetes and from a practical perspective, this is correct.

Actually after fermentation, most starch still is there, just a small part will be fermented. It is more the lower GI that matters.

You can say, that it might be "better" but if with your therapy you cannot keep the  BG levels low, it is still not "good" (or you have to change your therapy).

PaddyL's picture
PaddyL

...about the effects of sourdough bread vs regular bread, which stated that even white sourdough is better at controlling blood sugar spikes than a regular whole wheat bread.  It was a fairly scholarly study and I can't remember most of it, but I tried it, testing my blood two hours after eating white sourdough (with honey added) and my bs did not spike.  Unless I'm making a very lean bread, I always add a sweetener, sugar or honey or even maple syrup, but if a recipe calls for a lot of sugar, I generally cut down the amount.  As a diabetic, you want something that will slow down the absorption of sugars in your bloodstream, so try to stick to unprocessed ingredients as much as possible, or add something like oatmeal or bran to you bread.  Sugar is not forbidden for diabetics.  I'm type 2, controlled by oral meds and diet and exercise.  Good luck, and remember it's not the end of the world.

Heath's picture
Heath

This may be the article you saw.  It concludes that "with the sourdough, the subjects' blood sugar levels were lower for a similar rise in blood insulin.  What was even more interesting was that this positive effect remained during their second meal and lasted even hours after. This shows that what you have for breakfast influences how your body will respond to lunch."

So sourdough (even white) will cause a lower blood sugar level than regular bread (even wholewheat), and the effects last for hours afterwards.

PaddyL's picture
PaddyL

It has been quoted all over the internet.

hamletcat's picture
hamletcat

It doesn't exactly say why in the article, just that it has something to do with fermentation changing the nature of the starches.  What is interesting is that the study found whole wheat not as good for diabetics.  I know when I make whole wheat bread that the recipe calls for sugar, molasses and honey so it has a lot more sugar.  I don't know if that would have anything to do with it.  

Thanks so much for posting that article.  I think I better start learning how to make sourdough bread now.  Is there a link or something that a beginner can follow that is easy to get started?  I don't know if I should start a new thread for that.

 

Heath's picture
Heath

The easiest and quickest way to get a sourdough starter going in my experience (and according to lots of other people on this site) is Debra Wink's pineapple juice method: Part 1 and Part 2.  There's lots of scientific details in these posts, so if you don't want to read that just scroll down to the bottom of Part 2 for the instructions on how to create the starter.

chris319's picture
chris319

You might look into nut and bean flours. I've made biscuits from almond (expensive), garbanzo and soy flour and they ware good. Barley has a lower GI than wheat flour, but you want to add a small amount of wheat gluten or they will turn out crumbly.

hamletcat's picture
hamletcat

Could you share your soy flour and barley flour recipes with the wheat gluten?  I have all three of these and would really like some ideas on how to use them.  Thanks.

chris319's picture
chris319

It's a pretty standard buttermilk biscuit recipe. Use whatever flour you please.

1/2 C flour of your choice

1/4 tsp baking soda

1/8 tsp salt

Mix dry ingredients

1 TB oil

1/4 C cultured buttermilk, adjust to suit

Mix and drop biscuits onto a baking sheet or muffin pan

Bake at 400 degrees until golden brown, 20 minutes or so

I merely guessed and added 1 TB wheat gluten for the barley biscuits. You could add more if the biscuits are still crumbly and depending on batch size.

The acidic cultured buttermilk reacts with the baking soda and this is your leavening.

Garbanzo bean flour has a nice flavor once baked and it's not too expensive. Bean and nut flours tend to be unforgiving if your oven tends to heat things more on the bottom than the top.

Last year I figured I could grind my own garbanzo beans for about half the price of store-bought flour. That was a mistake. It was really difficult to get a nice, fine grind in the kitchen without a lot of waste (partially-ground coarse meal) so I gave up. With bean flours, the finer the grind the better. There are some things you pay the professionals to do. Finely-ground garbanzo flour requires a fancy mill and is one of those things.