“Largest study” on low-carb diet in T1D recruiting, to begin in Sweden in Fall; NYT profiles survey showing mean A1c ~5.7% with low-carb diet – May 17, 2018

Executive Highlights

  • The Dietary Science Foundation announced last week that the “largest study” of low-carb diets in type 1 diabetes has begun recruiting and will commence in the fall. The post doesn’t say exactly how large the study will be, but there are ~50,000 type 1s in Sweden. Well respected Karolinska University Hospital and Uppsala University Hospital are both participating centers.

  • Earlier this month, Pediatrics published and the New York Times covered a survey of people with type 1 diabetes that eat very low-carb diets. Surveyed individuals (n=316, mean age 27 years) had very low A1cs (~5.7%) and very low incidence of adverse events (2% reported diabetes-related hospitalizations in the past year). The survey adds important real-world data (especially in pediatrics) and serves as a solid foundation for the upcoming RCT.

  • The low-carb movement in metabolic disorders, especially in diabetes, has been gaining steam. Virta recently published data showing efficacy in type 2 diabetes (lower A1c, weight loss, reduced CVD biomarkers), and the Dietary Science Foundation alludes to positive results in fatty liver disease, as well as upcoming studies in type 2 diabetes and obesity.

  • The low-carb paradigm is obviously not for everyone, but is another important tool in the toolbox and one worth studying in far greater detail. Certainly many people with diabetes (Adam and Kelly included) have found it to be transformative. It will be key to understand if there is any impact on longer-term outcomes, especially the relationship between heart disease and any changes in total LDL cholesterol, LDL particle size, and LDL particle number (nuanced and hotly debated).

The Dietary Science Foundation, a Swedish organization that funds research into the effects of diet on health, recently announced that “the largest study so far on diet and type 1 diabetes” has received Ethical Review Board approval, is recruiting, and should begin this fall. The RCT – size not specified – will investigate the effect of a strict low-carb diet on blood sugar, insulin requirements, and blood lipids in type 1 patients.

Karolinska University Hospital and Uppsala University Hospital are among the participating centers, and researchers have already received funding from both public and private entities (insurance company Skandia, the Swedish Diabetes Foundation and Stockholm County Council). This is amazing support and we hope to see more studies like it, especially funded by ADA and JDRF – certainly diet is a critical lever in diabetes and we have not seen nearly enough robust studies.

We hope CGM is being used in diet trials going ahead, which will really show the nuances of average glucose/A1c vs. time-in-range/hypoglycemia. For example, in his two high carb vs. low carb experiments in diaTribe (here and here), Adam has shown similar average glucose levels but markedly different time-in-range, diabetes burden, and insulin needs.

The news comes on the heels of a survey (published in Pediatrics earlier this month) showing that people following a very low-carb diet (n=316; average age 27 years) had very low A1cs (~5.7%) and very low incidence of adverse events (2% reported diabetes-related hospitalizations in the past year). A well-written NYT article profiled the study and some people with type 1 succeeding on very low-carb diets. The obvious caveat is that respondents were selected from a Facebook group dedicated to low-carb diets (TypeOneGrit), suggesting high baseline engagement, education, motivation, etc. Still, we’re excited to see this publication, especially showing efficacy in pediatrics (a challenging population) and with Dr. David Ludwig on the author line. Certainly this should help pave the way for a large RCT!

The Dietary Science Foundation’s website also cites a study demonstrating that a low-carb diet is effective in treatment for fatty liver disease, touts a future study of a low-carb diet in type 2 diabetes (to be planned this Spring), and another future study looking at the role of carbs, saturated fats, and other macronutrients in obesity. 

  • Low-carb diets are certainly gaining steam across metabolic conditions. Virta Health, sporting a low-carb/high-fat ketogenic diet (<30 grams of carbs/day) plus tech-enabled remote care intervention for type 2s showed an impressive 60% diabetes “reversal” (A1c <6.5% and the elimination of all medications except metformin), an overall 1.3% A1c reduction (baseline: 7.6%) , and 12% bodyweight loss at one year. In Virta’s more recently published cardiovascular biomarker data at one year, there were significant improvements associated with the ketogenic diet in 22 of 26 risk factors, with a slight 10% increase in total LDL cholesterol (LDL-C). Consistent with these results, the respondents in the Pediatrics study also had elevated LDL-C, alongside low triglycerides and high HDL cholesterol. The authors suggest this phenotype would be consistent with large, buoyant lipoprotein particles, which is actually a relatively low-risk subtype.

    • Indeed, in the Framingham Offspring Study, LDL-P outperformed LDL-C for predicting CVD, and well-respected health experts Dr. Peter Attia and Kris Kresser have written extensively on this topic (here and here). The key nuance is that LDL-P and LDL-C are sometimes discordant, meaning it’s possible to have normal or even low LDL-C, but a high number of LDL particles. What matters for CVD, many now believe, is the number of LDL particles – especially the small ones.

  • Adam has written extensively on his experience eating low-carb in diaTribe and in his book, Bright Spot & Landmines. In his reflection column on 50,000 copies of the book, Adam highlights readers’ enthusiastic responses on this piece of the book, and also his response to criticism.


-- by Brian Levine, Adam Brown, and Kelly Close