Thank you for your letter dated the 19th November 2014.
I would like to address the two allegations separately because they may require different timeframes.
The first allegation is:
1. That my recommendation of a very low carbohydrate diet for type 2 diabetes management is inconsistent with Evidence Based Practice.
I thought that I had answered these questions but I sought out the help of two experts. Dr. Richard Feinman at the State University of New York in Brooklyn, NY explained to me that, as in a court of law, evidence has to be judged admissible and that you can’t be a judge for your own evidence as he describes the case of the American Diabetes Guidelines.
Dr. Feinman is the lead author on the just published review “Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base.” The review provides an evidence-based medicine perspective supporting low-carbohydrate diets. The paper has 26 authors with excellent credentials including at least one well-known former critic of low- carbohydrate diets.
To me this means that there is more than one acceptable approach to diabetes practice. If low-carbohydrate therapies are a minority, it seems that it is not a small minority and is not lacking in credentials.
Dr. Feinman said that he would like to correspond with you and has some suggestions for agreement.
Because the DAA recommends that dietitians follow the American Diabetes Association guidelines for dietary management of type 2 diabetes, I also contacted Dr. William Yancy who is a co-author of the guidelines. This is his response. (my emphasis):
Associate Professor Department of Medicine
Duke University Medical Center
The evidence supporting a low-carbohydrate diet is ample at this point. The only data we are missing is a trial with one of the ultimate disease endpoints like mortality or heart attacks. Of course, the low-fat/high-carbohydrate diet does not have evidence showing it improves those outcomes either—the trials that have been done were negative. And, in head-to-head trials with intermediate outcomes, low-carb diets quite clearly do better for improving HDL and triglycerides, and much of the time do better for
improving glycemia and weight. Since we did the evidence review for the ADA guidelines, 3 more RCTs in patients with DM have shown greater benefit with the low-carb diet.
One of the more useful head-to-head trials in patients with diabetes was performed in your country by Grant Brinkworth with Jeannie Tay as lead author. Published in Diabetes Care in 2014. In this study, the low-carb diet was low in saturated fat, which is unique, but it shows better glycemic improvements than the comparison diet and the decrease in saturated fat is not likely the driver of that. I am cc’ing him to see if he can be of assistance.”
In a second communication with Dr Yancy, I asked him to review my updated draft (see below) to the allegation before sending it to you, to check for accuracy and that my interpretation of the ADA’s guidelines is correct. His response:
I think this looks fine and can’t think of what else to add. Actually, one other comment to make is that in addition to better glycemic control in some head to head trials, another benefit that has been seen with the low carbohydrate diet has been a greater reduction in diabetes medication. This important for a few reasons: 1. It makes pts happy, 2. It reduces the potential for side effects (weight gain, hypoglycemia, others specific to the Rx class), and 3. It actually masks some of the glycemic improvement that is occurring.”
My personal response to the allegations:
DAA recommends that dietitians follow the American Diabetes Association guidelines for dietary management of type 2 diabetes.
The latest ADA guidelines are based on studies that the committee considers fit their stringent criteria. Such studies include trials comparing lower carb with higher carb intakes, and the committee found improved markers of glycemic control and insulin sensitivity with lower carbohydrate intakes. On that basis, they have stated that lower carb diets have a place in the management of type 2 diabetes.
They specifically mention that the diets that were assessed contained 21 g daily and up to 40% of daily energy intake from carbohydrate. The lower carb diets that I recommend to people with type 2 diabetes contain 21 g to 40% energy from carbohydrate. Therefore, my practice is in line with ADA recommendations and their Evidence Based Research.
Please let me know if there is any other information I can provide. Regards