If you have type 2 diabetes and are looking for a way to manage your condition, you may consider a low-carb diet. In today’s blog, we take a look at a recent study that showed evidence of type 2 diabetes remission after six months of a low-carb diet.
Let’s start with the basics; what is type 2 diabetes? Type 2 diabetes is an illness characterized by low tolerance to carbohydrates. You would think that people with diabetes will be more aware of the number of carbohydrates in their diets; however, some folks believe that the problem comes from overeating fat, which is a dangerous assumption.
One of the main discussion points in the PrevMed channel is the relationship between eating carbs excessively and high glucose levels. According to Mark Cucuzella, a professor of the West Virginia University School of Medicine, this can eventually lead people to take insulin for diabetes. Dr. Cucuzella has published several studies on dietary changes and diabetes; in these studies, people with problems metabolizing carbohydrates end up developing high insulin levels and hyperglycemia (high blood sugar levels).
Either of those things, high insulin levels or high glucose levels, can cause inflammation, which causes a burn of the lining of the artery wall.No matter what level of cholesterol, it will still pass through the artery wall lining when it has been damaged by high glucose or insulin,, although it won’t go through the next layer, the media or muscle layer, so it gets stuck between the intima layer. The result: plaque formation.
Until now, restricting carb intake in patients with type 2 diabetes has been a controversial topic, mainly because trial results have been inconclusive. Today we take a look at a systematic review and meta-analysis study published in the British Medical Journal (BMJ), one of the major medical journals in the world; it evaluated the efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission; they included 23 trials involving 1, 357 patients with type 2 diabetes.
Remember, a meta-analysis is not just one clinical trial; it’s a study of all clinical trials and studies that have been done and published; one more scientific publication came from a consensus report from the diabetes journal, looking to identify the impact of a low-carb diet. This particular meta-analysis showed the results of comparing the rates of type 2 diabetes remission between subjects that followed a low-carb diet versus those who didn’t during six months. Low carb diets were not only safe, they worked!
Now, that is the problem with randomized clinical trials; in a randomized clinical trial, you are using someone who has agreed to eat a certain way, they are only going to do it for a specific time, it has to be a permanent lifestyle change, it is not just a diet.
Jenny Ruhl runs an award-winning website for diabetics; it’s called Blood Sugar 101. She also wrote a book called Blood Sugar 101. In the book, you can learn an immense amount just by reading the first 60 pages. You can spend about an hour with that book and learn a lot about prediabetes; Jenny also wrote another book called Diet 101. In that book, she had a couple of critical things to say; one concept stands out from the rest: “eat to the glucometer,“ if you’re eating to the glucometer, you’re not going to have many arguments about eating a low carb versus high carb diet; the other thing that she brings up which is a critical point in Diet 101, the solution is not just a diet, and definitively is not something achievable only in six months.
Now you understand the problems in just doing a randomized, clinical diet trial- who will stay there for even six months?
The BMJ findings are consistent with the ADA’s 2019 recommendation on carbs, reducing overall carbohydrate intake for individuals with diabetes. This strategy improves glycemia, and people may apply it in various eating patterns that meet individual needs and preferences. This is a massive improvement over where they were in 2018, and before, ADA folks used to say “carb it up.” Previously, the ADA warned against diets under 130 grams of carbs a day. They thought people would be deprived of “essential nutrients.”
Let’s go back to the BMJ study of a low-carb diet. How did they define it? They defined it as 26% of daily calories coming from carbs; maybe you are doing some math on a 1600- 1700 calorie diet. Another option is the very low-carb diet, with around 10% of daily calories from carbs, which is more like a keto diet.
I’m asking questions and trying to sift fact versus misunderstanding; there’s no definition of carbs. It reminds me of the conversation that I had with David Meinz. He is in cardiovascular prevention and has been a public speaker for over 20 years. He was a supporter of the “Carb it up” the typical old style; a couple of years ago, he and I were sitting in his car before a meeting. David told me,” Ford, it’s so frustrating and embarrassing, I am a professional in dietetics. For many years I’ve been telling people to eat carbs”. Part of the confusion was 6-12 months before that conversation, he and I were in a debate at one of our meetings; I was on the low carb side, he was on the ADA side; I would say something about decreasing carbs, and he replied “Are you telling me to decrease broccoli, cauliflower, and asparagus? These are all high carb foods. They’re made of nothing but carbs. No, carb restriction only counts for glycemic carbs, carbs that raise your blood sugar. Broccoli, cauliflower, & asparagus do not raise your blood sugar. This is a blood sugar/insulin thing, not a fiber thing”
In the BMJ study, participants were evaluated at two intervals of 6 and 12 months; a primary outcome was type 2 diabetes remission. Speaking of definitions- what did they mean by remission for their study? Remission was defined as an hemoglobin A1c of less than 6.5 percent in subjects previously diagnosed with type 2 diabetes. Those of you who follow our channel know there’s a significant challenge in comparing A1cs between people. A1c is impacted by hemoglobin and fasting glucose less than seven millimoles, or 126 milligrams per deciliter with or without diabetes medication; that’s not the way I would define full-blown diabetes.
That’s one of several ways; I wouldn’t use the A1c; I use the peak glucose on an OGTT (oral glucose tolerance test). The BMJ study also talked about weight loss, A1c, fasting glucose, and adverse events in terms of trying to define someone as “in remission for type 2 diabetes.” They also looked at secondary outcomes to health-related quality of life biochemical laboratory data, but where’s the information about heart attack and stroke? There is no evaluation of those outcomes.
One of the critical things that we want to notice at six months: the low carb diets achieved a 32% diabetes remission; that is higher than the other diets, remission was defined as A1c less than 6.5 and as fasting glucose less than seven or more than 126 mg/dl.
Other minor, non-significant effects occurred without diabetes medication; Additional benefits for the low-carb diet brought extensive improvements in weight loss, significant weight loss. I can tell you from doing this for a living; there is nothing like losing body fat to improve this situation. They may have been using slightly different definitions, but we’re all focusing on the same issue.
Researchers acknowledge weight loss as the primary driver of remission; I do this all day, every day, and I can tell you, weight loss is king; however, while low carb groups lost more weight compared to the control groups (around 7.4 kilograms), about 15 pounds, the weight difference, as well as remission, disappeared after 12 months.
Remember what we talked about- these are clinical trials? In other words, you’re randomized for six months. “I’m going to agree to this diet” they’re not committed to making a change in their lifestyle. The decreased benefits may have occurred because patients stopped sticking to the diet over time.
BMJ ends up calling for more research to be done exploring long-term adherence and effects. From my own experience, I have a few folks who do very well on a ketogenic diet. More folks more often do better on a kinder, gentler, low carb diet of 50 to 125 carbs/day. It’s just easier to stick to this kind of diet; it is not a sprint which only lasts 8-9 seconds; it is not a marathon- marathons last between 2-6 hours, depending on how fast or slow you are; this is month after month, year after year, decade after decade. This is a permanent change.
Very low-carb diets were less effective than low-carb diets for weight loss; however, this may have been explained by diet adherence. People on the very low-carb diets had more difficulty adhering to the very low-carb diet. The idea of diabetes remission is somewhat a new thought, and that is because we don’t have enough evidence yet that remission is permanent; a lot of research is needed; if it’s not permanent, the weight loss will decrease.
One thing is clear, if you lose body fat, you will improve your insulin resistance; once we get past age 65, we have to be very careful that it’s not just losing weight- it’s losing body fat. Age 65 and older is notorious for maintaining the same circumference, the exact size of your leg; still, muscle is being replaced with fat. That situation is dangerous; it’s one of the biggest causes of cardiovascular inflammation and insulin resistance.
Going back to a low-carb diet, the amount of carbs people consumed on a low-carb diet varied, ranging from less than 26% to 45% of daily calories from carbs; that’s not a low-carb diet to me, unless my math is wrong. That’s a very gentle, effortless diet, unless it includes broccoli and fiber related carbs, which could impact whether some low carb diets work better than others.
None of the studies control protein intake; many of the low carb diets doubled the calories from protein. This could have impacted the chance of remission. None of the studies considered medication use which made it difficult to see the impact of low-carb diets alone.
When beginning a low-carb diet, it’s essential to monitor blood sugar levels; it’s also crucial to have the assistance of a doctor or registered dietitian who specializes in diabetes and nutrition. When you talk to the doctor and dietician, find out if they’re open and amenable to a low-carb diet. Over the past couple of years, many of them have made that transition, even the ADA has made that transition.
It is not as frequent, but you still see dieticians and doctors who keep saying, ” low carb is bad.” I disagree with that assessment.
- BMJ 2021;372:m4743 available at https://www.bmj.com/content/372/bmj.m4743
- Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report available at. https://care.diabetesjournals.org/content/diacare/early/2019/04/10/dci19-0014.full.pdf