Med diet beats low-fat for diabetes benefits: Study

Consuming a Mediterranean-style diet, rich in vegetables, fruits and nuts, olive oil, and legumes, is more effective for diabetes control than a low-fat diet, says a new study.

In addition to improvements in blood sugar control, as well as coronary risk factors, the Mediterranean style diet also delayed the need for anti-hyperglycemic drug therapy in overweight patients with type-2 diabetes, according to findings published in the Annals of Internal Medicine.

“Perhaps most important, the findings reinforce the message that benefits of lifestyle interventions should not be overlooked despite the drug-intensive style of medicine fueled by the current medical literature,” wrote the researchers, led by Katherine Esposito from the Second University of Naples.

An estimated 19 million people are affected by diabetes in the EU 25, equal to four per cent of the total population. This figure is projected to increase to 26 million by 2030.

In the US, there are almost 24 million people with diabetes, equal to 8 per cent of the population. The total costs are thought to be as much as $174 billion, with $116 billion being direct costs from medication, according to 2005-2007 American Diabetes Association figures.

If the results of the new study are repeated in the future it may see a reduction in these excessive medication costs, as the Neapolitan researchers report: “Participants assigned to the Mediterranean-style diet lost more weight and experienced greater improvements in some glycemic control and coronary risk measures than did those assigned to the low-fat diet.”

The Med diet, rich in cereals, wine, fruits, nuts, legumes and whole grains, fish and olive oil, and low in dairy, meat, junk food and fat , has been linked to longer life, less heart disease, and protection against some cancers. The diet's main nutritional components include beta-carotene, vitamin C, tocopherols, polyphenols, and essential minerals.

Study details

Esposito and her co-workers recruited 215 overweight people with newly diagnosed type-2 diabetes and randomly assigned them to consume the Mediterranean-style diet, characterized by less than half of all daily calories being obtained from carbohydrates, or a low-fat diet, characterized by less than 30 per cent of all daily calories coming from fat.

After four years of study, the researchers note that only 44 per cent of people in the Mediterranean-style diet group required anti-hyperglycemic drug treatment, compared to 70 per cent in the low-fat diet group.

While both diets were associated with weight loss, the Mediterranean-style diet was associated with a 2 kg greater loss, as well as greater improvements in body mass index (BMI).

Benefits beyond weight loss

“The between-group difference in the proportion of people needing anti-hyperglycemic drug therapy increased over the course of the trial and favored the MED diet, whereas the between-group differences in weight loss decreased,” wrote the researchers.

“Analyses adjusted for weight change suggested a statistically significant reduced rate of needing drug therapy, so the effect of the MED diet goes beyond weight reduction.

“Consumption of monounsaturated fatty acids is thought to increase insulin sensitivity, and this component of the diet might explain the favorable effect of the MED diet on the need for drug therapy,” they added.

The researchers note that their study was not double-blind, and that this may be a limitation for the study.

The study was primarily funded by the Second University of Naples.

Source: Annals of Internal Medicine

Volume 151, Pages 306-314

“Effects of a Mediterranean-Style Diet on the Need for Antihyperglycemic Drug Therapy in Patients With Newly Diagnosed Type 2 Diabetes - A Randomized Trial”

Authors: K. Esposito, M.I. Maiorino, M. Ciotola, C. Di Palo, P. Scognamiglio, M. Gicchino, M. Petrizzo, F. Saccomanno, F. Beneduce, A. Ceriello, D. Giugliano