From the Guidelines
The Mediterranean diet can lower Hemoglobin A1c (HbA1c) levels by approximately 0.3% to 0.5% in patients with Type 2 diabetes mellitus, as reported in a meta-analysis of RCTs 1. This reduction in HbA1c levels is a result of the diet's emphasis on foods that improve insulin sensitivity, reduce inflammation, and provide antioxidants, such as olive oil, vegetables, fruits, whole grains, legumes, nuts, and moderate consumption of fish and poultry. Some key components of the Mediterranean diet include:
- Consuming 3-4 tablespoons of extra virgin olive oil daily
- Eating at least 3 servings of vegetables and 2 servings of fruit
- Having 3 servings of whole grains
- Incorporating 3 servings of legumes weekly
- Eating fish 2-3 times per week The Mediterranean diet works by improving insulin sensitivity, reducing inflammation, and providing antioxidants that help manage oxidative stress, with the high fiber content slowing carbohydrate absorption and preventing blood glucose spikes 1. It is essential for patients with Type 2 diabetes to follow this dietary approach in conjunction with prescribed diabetes medications and regular blood glucose monitoring, rather than using it as a replacement for medical treatment.
From the Research
Reduction in HbA1c Levels
The Mediterranean diet has been shown to lower HbA1c levels in patients with Type 2 diabetes. The average reduction in HbA1c levels varies across studies, but the following points summarize the key findings:
- A study published in 2014 found that the Mediterranean diet improved HbA1c levels, with a reduction ranging from 0.1% to 0.6% 2.
- A 2009 study reported that diabetic patients with high adherence to a Mediterranean-type diet had lower HbA1c levels, with a difference of 0.9% compared to those with low adherence 3.
- A 2017 review stated that the Mediterranean diet reduces glycosylated hemoglobin levels by 0.30-0.47% 4.
- A 2011 study found an inverse non-significant association between adherence to the Mediterranean diet and HbA1c levels, although the results were not statistically significant 5.
Key Findings
The Mediterranean diet has been consistently associated with improved glycemic control and reduced cardiovascular risk factors in patients with Type 2 diabetes. The key findings include: