In newly diagnosed type 2 diabetes mellitus, a Mediterranean diet (vs. a low-fat diet) delayed start of glucose-lowering drugs

Patients who were randomized to a low-carbohydrate Mediterranean diet (LCMD) shortly after type 2 diabetes diagnosis delayed their need for medication compared to those put on a low-fat diet (LFD) in an Italian trial. Among the 108 patients on the LCMD, median time to the start of medication was 4.8 years, compared to 2.8 years in the 107 patients on the LFD. The LCMD group was also significantly more likely to have complete or partial remission of diabetes.

The study was published in Diabetes Care in July. The following commentary by Eugene C. Corbett Jr., MD, MACP, was published in the ACP Journal Club section of the Sept. 16 Annals of Internal Medicine.

The randomized trial by Esposito and colleagues found that, compared with an LFD, a caloric-equivalent LCMD was more likely to improve glucose levels and delay the need for glucose-lowering medications in patients with newly diagnosed type 2 diabetes. Key dietary features of the LCMD were ≤50% of calories from carbohydrates and ≥30% of calories from fat, with an emphasis on vegetables, whole grains, poultry and fish, and 30 to 50 g/d of olive oil. Both clinicians and patients with diabetes will appreciate learning that such a dietary pattern can delay pharmacologic intervention and, in some patients, achieve normal glycemic control. However, maintaining a similar level of dietary adherence in patients with type 2 diabetes can be challenging.

Implementing a medical home model that includes dietitians, diabetes educators, or other members of the health care team to help educate patients and promote sustained dietary change and physical activity may be beneficial. Otherwise, individual clinicians will have to rely on their ability to stimulate sustained self-care behavior in patients. This highlights the importance of the physician–patient relationship as well as the role of patient choice in clinical decision-making. For example, some patients may prefer immediate pharmacologic treatment rather than switching to a diet that they may not follow. Another major challenge may be having patients follow a regular physical activity level similar to that in the study by Esposito and colleagues.

Given the meaningful effects on surrogate diabetes outcomes, longer-term study of the effect of a sustained LCMD on cardiovascular and other diabetes-related outcomes is needed. The LOOK AHEAD trial, which focused on an older population with a longer history of diabetes, showed that intensive lifestyle change, including an LFD, resulted in weight loss and improved glycemic control but did not reduce cardiovascular events. Perhaps lifestyle change focused on an LCMD in the early stage of type 2 diabetes could have more long-term cardiovascular benefits.