Eddy Edson
Well-Known Member
- Relationship to Diabetes
- In remission from Type 2
I mentioned this in some other thread, but think it's worth highlighting. Bread was the single biggest issue I had to get a handle on while getting BG under better control & that's probably true for a bunch of other T2's as well.
http://austinpublishinggroup.com/clinical-medicine/download.php?file=fulltext/ajcm-v5-id1031.pdf
Caveats: This is a small study in what I think is probably a low-impact journal, so take with a pinch of salt. But fascinating, and it's consistent with some of my experience.
The researchers looked at how a group of "normal" people reacted to a range of commercially-available breads, in terms of glucose response and glycemic index. Conclusion: There's so much individual variability that the notion of a single GI number for any type of bread is highly misleading & it's really not possible to formulate useful general dietary guidelines.
The key figure below: bit hard to read, apols.
Fig A shows average BG levels over 120 min after eating a standardised amount (50g carbs) of each type of bread. Not surprisingly, white bread on average peaks highest, at around 7.8. But whole-meal roll is almost as bad, and BG levels are *above* white bread for most of the second hour. Oat bread peaks lowest.
These are just averages; Fig B and Fig C show the huge variability hidden in those averages.
Fig B shows peak levels. The bar in each box is the average, corresponding to the points plotted in Fig A. The boxes themselves are basically +/- 1 standard deviation, so covering about two-thirds of the people. The end points represents +/- 2 SD, so covering about 95%.
Look at white bread. The 95% coverage spans ~6.6 to ~9.6, really a pretty big range. Remember, this is for "normal" people, all starting with a fasting level of around 5. One point: any T2D who worries a lot about peaking above 8 or whatever, should probably stop it. It's "normal", depending on what you eat, and consistent with recent CGM studies which show "normal" avg daily highs in the 8.0 +/- 1.3 range in the 1-SD interval, so plenty of people go even higher than 9.3.
More interesting is the comparison with other breads. What conclusions can you draw about which bread is "better"? Answer: Not much. Only the rye and oat breads show any statistically significant difference. But even with oat bread, overall the best, there are plenty of people who "spike" higher than other people do with white bread. And look at that range for spelt!
Fig C shows individual glycemic index calculations, referenced to white bread. Again, there's just too much variability for a single GI measure to make sense or to be particularly useful at an individual level. Oat bread is best at a "population" level, but for plenty of people it has a *higher* GI than white bread does for them.
As the authors say:
This study reports large variations in the impacts of various wholegrain- based breads on relevant T2DM-related parameters and indicates complex nutritional relationships and individual response characteristics. Therefore, it is difficult to provide recommendations for effective food-based dietary guidance for patients. In general, bread with reduced carbohydrate content in combination with high fiber, protein and fat content seems to be preferable, but dietary optimization for each individual is necessary.
Probably the same is true for fruits and other BG-sensitive foods. Formulating general guidelines based on population means seems like a losing game and the risk is that such guidelines in the worst case might be appropriate for *no* individual diabetic.
No alternative really to doing your own testing and working out what works and doesn't work for you as an individual. For many things, best to ignore any advice which says you must or must not eat this or that, IMO.
http://austinpublishinggroup.com/clinical-medicine/download.php?file=fulltext/ajcm-v5-id1031.pdf
Caveats: This is a small study in what I think is probably a low-impact journal, so take with a pinch of salt. But fascinating, and it's consistent with some of my experience.
The researchers looked at how a group of "normal" people reacted to a range of commercially-available breads, in terms of glucose response and glycemic index. Conclusion: There's so much individual variability that the notion of a single GI number for any type of bread is highly misleading & it's really not possible to formulate useful general dietary guidelines.
The key figure below: bit hard to read, apols.
Fig A shows average BG levels over 120 min after eating a standardised amount (50g carbs) of each type of bread. Not surprisingly, white bread on average peaks highest, at around 7.8. But whole-meal roll is almost as bad, and BG levels are *above* white bread for most of the second hour. Oat bread peaks lowest.
These are just averages; Fig B and Fig C show the huge variability hidden in those averages.
Fig B shows peak levels. The bar in each box is the average, corresponding to the points plotted in Fig A. The boxes themselves are basically +/- 1 standard deviation, so covering about two-thirds of the people. The end points represents +/- 2 SD, so covering about 95%.
Look at white bread. The 95% coverage spans ~6.6 to ~9.6, really a pretty big range. Remember, this is for "normal" people, all starting with a fasting level of around 5. One point: any T2D who worries a lot about peaking above 8 or whatever, should probably stop it. It's "normal", depending on what you eat, and consistent with recent CGM studies which show "normal" avg daily highs in the 8.0 +/- 1.3 range in the 1-SD interval, so plenty of people go even higher than 9.3.
More interesting is the comparison with other breads. What conclusions can you draw about which bread is "better"? Answer: Not much. Only the rye and oat breads show any statistically significant difference. But even with oat bread, overall the best, there are plenty of people who "spike" higher than other people do with white bread. And look at that range for spelt!
Fig C shows individual glycemic index calculations, referenced to white bread. Again, there's just too much variability for a single GI measure to make sense or to be particularly useful at an individual level. Oat bread is best at a "population" level, but for plenty of people it has a *higher* GI than white bread does for them.
As the authors say:
This study reports large variations in the impacts of various wholegrain- based breads on relevant T2DM-related parameters and indicates complex nutritional relationships and individual response characteristics. Therefore, it is difficult to provide recommendations for effective food-based dietary guidance for patients. In general, bread with reduced carbohydrate content in combination with high fiber, protein and fat content seems to be preferable, but dietary optimization for each individual is necessary.
Probably the same is true for fruits and other BG-sensitive foods. Formulating general guidelines based on population means seems like a losing game and the risk is that such guidelines in the worst case might be appropriate for *no* individual diabetic.
No alternative really to doing your own testing and working out what works and doesn't work for you as an individual. For many things, best to ignore any advice which says you must or must not eat this or that, IMO.
