1. A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses

A systematic review aimed to evaluate the efficacy of the Mediterranean diet in managing type 2 diabetes and prediabetic conditions.

It included 2824 studies and identified 8 meta-analyses and 5 randomized controlled trials (RCTs) meeting inclusion criteria. These studies compared the Mediterranean diet with control diets in participants with or at risk for type 2 diabetes.

Criteria for inclusion in meta-analyses required trials to have a control group with another diet, a duration of at least 6 months, and a minimum of 30 participants in each arm.

Meta-analyses of long-term RCTs favored the Mediterranean diet for improving glycaemic control and increasing the probability of remission from metabolic syndrome by 49%.

Additionally, 5 meta-analyses highlighted its positive effects on body weight, total cholesterol, and high-density lipoprotein cholesterol compared to other diets.

Furthermore, adherence to the Mediterranean diet was associated with a reduced risk of future diabetes by 19-23%, as indicated by 2 meta-analyses.

In conclusion, the Mediterranean diet exhibited superior outcomes in glycaemic control and cardiovascular risk factors compared to control diets, including lower fat diets.

These findings suggest its suitability for overall management in individuals with type 2 diabetes or those at risk for it.

2. Schwingshackl, L., Missbach, B., König, J. and Hoffmann, G., 2015. Adherence to a Mediterranean diet and risk of diabetes: a systematic review and meta-analysis. Public health nutrition, 18(7), pp.1292-1299.

A systematic review and meta-analysis aimed to assess the impact of adhering to a Mediterranean diet on the risk of type 2 diabetes mellitus.

Electronic searches of databases until April 2, 2014, identified one randomized controlled trial and eight prospective cohort studies, comprising 122,810 subjects, published between 2007 and 2014. Eligible participants were aged 19 years and above.

Pooled analysis revealed that the highest adherence to the Mediterranean diet was associated with a significantly reduced risk of type 2 diabetes mellitus compared to the lowest adherence, with a pooled risk ratio of 0.81 (95% CI 0.73, 0.90, p<0.0001, I2=55%).

Sensitivity analysis focusing on long-term studies reaffirmed these findings, showing a pooled risk ratio of 0.75 (95% CI 0.68, 0.83, p<0.00001, I2=0%). Furthermore, the Egger regression test indicated no substantial publication bias (p=0.254).

In conclusion, higher adherence to a Mediterranean diet is associated with a notable 19% reduction in the risk of developing diabetes, supported by moderate quality evidence.

These findings hold clinical relevance for public health initiatives, suggesting the promotion of a Mediterranean-like dietary pattern for primary prevention of type 2 diabetes mellitus.

3. Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes

Background:
There is evidence that reducing blood glucose concentrations, inducing weight loss, and improving the lipid profile reduces cardiovascular risk in people with type 2 diabetes.

Assessing the effect of various diets on glycemic control, lipids, and weight loss.

Searches of PubMed, Embase, and Google Scholar to August 2011. Randomized controlled trials (RCTs) with interventions that lasted ≥6 mo that compared low-carbohydrate, vegetarian, vegan, low–glycemic index (GI), high-fiber, Mediterranean, and high-protein diets with control diets including low-fat, high-GI, American Diabetes Association, European Association for the Study of Diabetes, and low-protein diets.

A total of 20 RCTs were included (n = 3073 included in final analyses across 3460 randomly assigned individuals).

The low-carbohydrate, low-GI, Mediterranean, and high-protein diets all led to a greater improvement in glycemic control [glycated hemoglobin reductions of −0.12% (P = 0.04), −0.14% (P = 0.008), −0.47% (P < 0.00001), and −0.28% (P < 0.00001), respectively] compared with their respective control diets, with the largest effect size seen in the Mediterranean diet.

Low-carbohydrate and Mediterranean diets led to greater weight loss [−0.69 kg (P = 0.21) and −1.84 kg (P < 0.00001), respectively], with an increase in HDL seen in all diets except the high-protein diet.

Low-carbohydrate, low-GI, Mediterranean, and high-protein diets are effective in improving various markers of cardiovascular risk in people with diabetes and should be considered in the overall strategy of diabetes management.

4. The Effect of the Mediterranean Diet on Metabolic Health: A Systematic Review and Meta-Analysis of Controlled Trials in Adults

This systematic review with meta-analysis aimed to evaluate the effects of the Mediterranean diet (MD) on various metabolic health outcomes, including metabolic syndrome incidence, components, and risk factors as primary outcomes, and incidence and mortality from MetSyn-related co-morbidities and pharmacologic treatment for MetSyn components and co-morbidities as secondary outcomes.

Reviewed 84 articles reporting 57 trials involving 36,983 participants. The MD exhibited favourable changes in 18 of 28 MetSyn components and risk factors, including body weight, blood pressure, glucose, lipids, and inflammatory markers. It also lowered the risk of cardiovascular disease incidence and stroke.

However, only a few studies reported effects on pharmacotherapy use, with no significant differences between diet groups.

Despite observed heterogeneity in study characteristics and comparator groups, the MD consistently demonstrated beneficial effects on metabolic health outcomes. The meta-analysis highlighted the need for more studies to establish effects on additional clinical outcomes and pharmacotherapy use. While some outcomes exhibited high levels of heterogeneity, the overall direction of effect favored the MD's benefits on metabolic health.

These findings emphasize the importance of promoting the MD dietary pattern among adult populations for its potential to improve metabolic health and reduce the risk of MetSyn-related complications. Continued research in this area is warranted to further elucidate the comprehensive effects of the MD on metabolic health.

5. The Mediterranean diets: what is so special about the diet of Greece?

The countries around the Mediterranean basin have different diets, religions and cultures. Their diets differ in the amount of total fat, olive oil, type of meat and wine intake; milk vs. cheese; fruits and vegetables; and the rates of coronary heart disease and cancer, with the lower death rates and longer life expectancy occurring in Greece.

Extensive studies on the traditional diet of Greece (the diet before 1960) indicate that the dietary pattern of Greeks consists of a high intake of fruits, vegetables (particularly wild plants), nuts and cereals mostly in the form of sourdough bread rather than pasta; more olive oil and olives;

less milk but more cheese; more fish; less meat; and moderate amounts of wine, more so than other Mediterranean countries.

Analyses of the dietary pattern of the diet of Crete shows a number of protective substances, such as selenium, glutathione, a balanced ratio of (n-6):(n-3) essential fatty acids (EFA), high amounts of fiber, antioxidants (especially resveratrol from wine and polyphenols from olive oil), vitamins E and C.

Some of which have been shown to be associated with lower risk of cancer, including cancer of the breast. These findings should serve as a strong incentive for the initiation of intervention trials that will test the effect of specific dietary patterns in the prevention and management of patients with cancer.

6. Transferability of the Mediterranean diet to non-Mediterranean countries. What is and what is not the Mediterranean diet.


The Mediterranean diet (MedDiet) has been extensively studied and proven effective in preventing cardiovascular disease (CVD) and promoting longevity.

A cumulative meta-analysis supports its association with reduced incidence of CVD events. While popular globally, misconceptions about the traditional MedDiet persist.

Clearing these myths is essential. Adapting the MedDiet to non-Mediterranean populations is feasible but requires significant dietary changes.

New approaches are needed to promote MedDiet-consistent eating habits for public health.