For years, the legacy of the ADA (American Diabetes Association) and the ADtA (American Dietetic Association) (now staking the claim to the name Academy of Nutrition and Dietiecs (AND)) dietary recommendations have held up, arguing that diabetics should follow a high carb, low fat diet. The flag for this fight was handed off from the ADA to AND, but the individuals involved pretty much remained the same (a group of old guard non scientists with representation from industry).
The latest incarnate of their recommendations can be read in the JADA article "The Evidence for MNT for Type 1 and Type 2 Diabetes in Adults". I read through it and found it terribly flawed, just like its predecessor. And we continue to get flawed dietary advice based on this work. This is the core substantiation that is used to educate us on appropriate nutrition for managing our diabetes.
But the cracks may be widening. The latest salvo appears in the Diabetes Care issue with the article "Macronutrients, Food Groups, and Eating Patterns in the Management of Diabetes, A systematic review of the literature, 2010" Key findings on carbohydrates seem in total opposition to the AND assessment above.
Low Carb Findings (Up to 30% of calories from carbs)
In studies reducing total carbohydrate intake, markers of glycemic control and insulin sensitivity improved, but studies were small, of short duration, and in some cases were not randomized or had high dropout rates. Serum lipoproteins typically improved with reduction of total carbohydrate intake but, with the exception of HDL cholesterol, were not statistically greater than with the comparison diet. The contribution of weight loss to the results was not clear in some of these studies.
Moderate (40-65% of calories/carbs) to High (> 65%) Carb Findings
RCTs presenting information on moderate- and high-carbohydrate diets are diverse in terms of fat and protein content as well as length of study. Only two RCTs found significant differences in A1C between groups, with one study finding significantly lower A1C with the higher-carbohydrate diet only in a subgroup analysis, and the other study finding significantly lower A1C with the lower-carbohydrate diet. In terms of CVD risk factors, LDL cholesterol improved more with a high-carbohydrate diet in one study, whereas two studies found TGs improved more with a lower-carbohydrate diet.
Based on this assessment, it seems like a no brainer. The results suggest clear improvements in blood sugar control and no identified lipid problems with low carb diets. But no research seems to support the effectiveness of high carb diets. It doesn't really help your blood sugar control and it doesn't help your lipids either. The key argument has always been that low carb diets are a CVD risk because of adverse affects on lipids. Even if you believe the lipid hypothesis, this suggestst that low carb diets are heart healthy.
What do you all think of this? Is it progress? Will Hope Warshaw read it and understand it? Will it help lead to more progressive diet assessments and recommendations?
In either case, for those of you who have to deal with nutritionists and dieticians, print this journal article out. If you get harrassment from your medical team about following a low carb diet, you can pull this study out and show them that you are following a diet with some compelling evidence behind it.