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Transcript: High Protein vs. High Carbohydrate

Comments from Richard K. Bernstein, MD

See the video here.


Steve Freed:  This is Steve Freed with Diabetes in Control and we’re here today with a very special guest, Dr. Richard K. Bernstein, who is well-known across the globe and is the author of the best-selling diabetes books Dr. Bernstein’s Diabetes Solution and Dr. Bernstein’s Diabetes Diet. Dr. Bernstein, we know you’re a proponent of the low-carb diet, and recently the BMJ published, actually last week, a study entitled “Remission of Prediabetes to Normal Glucose Tolerance in Obese Adults with High Protein versus High Carbohydrate Diet: A Randomized Controlled Trial.” Can you discuss some of these results?

Dr. Bernstein:  Yes, I’d be glad to. First of all, the study entailed only 24 individuals. 12 on high carbo, 12 on high protein. But it was so meticulously performed that the value of this study is considerable. What they did was they bought supermarket meals and froze them and allowed the patients in the study to consume only these meals for six months. So this is a six-month study where they only ate the designated meals. They selected people who they called prediabetic, and what were the conditions for being prediabetic? Well, first of all their hemoglobin A1C was between 5.7 and 6.4. Now by my standards that’s diabetic, but not by the usual standards. Most doctors would consider that prediabetic. The average A1C was 6.0 before the start of the trial. Another criterion for prediabetes was an oral glucose tolerance test with 2-hour values between 140 and 199 mg per deciliter. Also, fasting blood sugars over 126. After this six-month trial, the A1C went down a little bit. It went down from 6.0 to 5.46, but most dramatically, the fasting blood sugar went below 100 for all of them and the two-hour post glucose tolerance test went under 140, so we have from initially 140 to 199 to under 140. So, clearly, a significant reversal. Now how much protein and carbohydrate were these people eating? It’s interesting that there was not a big difference between the two groups. The high carbo had 15% protein, 55% carbo and the balance 30% fat. The high protein had 30% protein, so twice as much protein, 40% carbohydrate, which is only a slight drop from 55% high carb to 40% for the low carb, not much of a drop, and 30% fat. So there were isocaloric, both groups were consuming the same amount of calories and there were lower caloric amounts than the people were used to, so they did lose a little bit of weight in this six-month period. The two groups lost the same amount of weight, so whatever end differences occurred was not due to weight loss, because weight loss was the same. Now, in addition to finding normalization of the glucose tolerance test, which is impressive, many cardiac risk factors and risk factors for other diseases dropped dramatically in the low-carbohydrate group. Going down the list for example. We had lowered blood pressure, lowered triglycerides, lower LDL, lowered total cholesterol, higher HDL, lower reactive oxygen species, dramatic lowering of interleukin 6, which is an inflammatory marker from 8.5 to 4.5 and ultra-dramatic lowering of tumor necrosis factor alpha, which is a risk factor for many ailments, including malignancies. TNFα went down from 13 to 4. So this was a very dramatic study, and quite impressive in spite of the small numbers. But I should point out a couple of things.

Number one, the diagnosis of prediabetes to me was really overt diabetes, because I think everyone should have normal blood sugars, and in the general population, large scale studies show that lowest mortality is with blood sugars around 83 mg per deciliter. Additionally, the carbohydrate reduction was very small. I and my patients consume less than 5% of calories as carbohydrate and it’s mostly that carbohydrate is essentially vegetables, low carb vegetables, and we don’t suffer from malnutrition; and one other point to be made is that critics of this study, aside from criticizing the small numbers, are going to say, “Well, there’s no evidence that long-term low-carbohydrate diets or high-protein diets are safe.” Aside from looking at our ancestors who ate that way, we have right here in my office, two type one diabetics who have been on a very low carb diet for many years. I’ve been on the diet since 1969, which I think is something like 47 years, and I had advanced kidney disease before I went on this diet; and in my office is another physician from Oman, he had advanced kidney disease, and has been on this diet for 15 years, reversing his kidney disease. So, aside from my many patients on low carbohydrate diets for many years, we have us two. I just got phone calls in the past week from patients of mine who have been on this diet since they were children and are now in their 50s or 40s who have been on for 30 years or so. So, my experience is that you’re a lot healthier with a low-carb / high-protein diet.

Steve Freed:  This study pertains to prediabetes. Now can we take that information and apply it to someone with not only type 2 but type 1 diabetes?

Dr. Bernstein: Of course, remember, my personal experience is with type 1 diabetes. But I do get a goodly number of patients who come here having read one of my books that said an A1C of 5.9 or 6 is on the high side and they don’t want to develop diabetes. What we do is put them on the low carb. The first jump that we do is a low-carb diet, we’ll also lose weight if they’re overweight, and we’ll also try to get them to exercise. What we achieve is normal blood sugars. Did we reverse the diabetes? It’s hard to tell because I never gave them a glucose tolerance test after the fact, just looked at A1Cs, which we can get down into, let’s  [say] 4.2 to 4.6 if we’re lucky, maybe 4.8, 4.9, and is that reversal of the disease? Well, I didn’t test to see what would happen if we put them on high carbohydrate diets and saw if their blood sugars remained normal. Because that would be true reversal and of course in this study, they gave them a follow-up glucose tolerance test, which was normal. I never did that. But I do see A1Cs normalizing in prediabetics. I’ve seen plenty of prediabetics as well as diabetics and they both benefit from this.

Steve Freed: I want to thank you for your time. I think it’s very interesting and remind people they should check out your book. Dr. Bernstein’s Diabetes Diet, Dr. Bernstein’s Diabetes Solution. I know it’s over 500 pages of unbelievable information and if people do get the book, they need to read it at least 3 to 5 times, because there’s no way to comprehend all the great information that you spent your life basically putting together to help people. So, with that I want to say thank you. Any last comments?

Dr. Bernstein:  I always have the same last comment, that diabetics are entitled to the same blood sugars as non-diabetics. It’s only very exceptional cases where you would violate that, like people who are dying anyway.


BMJ Open Diab Res Care 2016;4:e000258 doi:10.1136/bmjdrc-2016-000258