The following article by Mark L. Fuerst is reprinted from Psychiatric Times, March 31, 2014.

Two new studies show the heart-healthy benefits of eating a Mediterranean diet.

One study linked the diet to a lower risk of diabetes mellitus (DM), especially among those at high risk for cardiovascular disease…

In the first pooled analysis of studies evaluating the possible role of the Mediterranean diet in DM development, adherence to this diet was associated with a 21% reduced risk of DM compared with the control dietary groups. The likelihood of developing DM was almost 27% less in those at high risk for cardiovascular disease than in controls.

“Adherence to the Mediterranean diet may prevent the development of diabetes irrespective of age, sex, race, or culture,” said lead investigator Demosthenes Panagiotakos, PhD, professor at Harokopio University, Athens, Greece. “This diet has a beneficial effect, even in high risk groups, and speaks to the fact that it is never too late to start eating a healthy diet…”

The Mediterranean diet frequently emphasizes fresh fruits and vegetables, whole grains, beans, nuts, fi sh, olive oil, and even a glass of red wine.

Dr. Panagiotakos said he believes the Mediterranean diet lowers the risk of DM by helping guard against obesity. Earlier research has shown that following the traditional Mediterranean diet also is linked to weight loss, a reduced risk of heart disease and related death, and lower blood pressure and blood cholesterol levels…

[In a second study], Italian researchers conducted an analysis of the eating habits of nearly 15,000 healthy Italian men and women aged 35 years or older…

The investigators observed that consumption of the Mediterranean diet was directly related to lower levels of platelets and white blood cells, which, in turn, correlated to lower levels of inflammation [which has been associated with a greater risk of myocardial infarction (heart attack) and stroke].

For more detailed information on these studies, please see the following: Mediterranean diet and diabetes mellitus:

The following is excerpted from an article published on the website of the U.S. National Library of Medicine, May 11, 2015.

Adding more olive oil or nuts to a Mediterranean diet—one rich in fruits, vegetables, fi sh, and whole grains and low in red meat—may help keep your mind sharper as you age, a new study suggests.

The Spanish researchers found that seniors following such diets had greater improvements in thinking and memory than people who were simply advised to eat a lower-fat diet.

“You can delay the onset of age-related mental decline with a healthy diet rich in foods with a high antioxidant power, such as virgin olive oil and nuts,” said lead researcher Dr. Emilio Ros, director of the lipid clinic at the Hospital Clinic in Barcelona.

“Because the average age of participants was 67 when the trial began, one can say that it is never too late to change your diet to maintain or even improve brain function,” he said.

The report was published online May 11 in the journal JAMA Internal Medicine.

Dr. Sam Gandy, director of the Center for Cognitive Health at Mount Sinai Hospital in New York City, said, “The general heart-healthy and brain-healthy effects of eating less beef and more chicken, fi sh, fruits and vegetables [have] been validated to the point that I now recommend this general Mediterranean diet to all my patients.”

…. Participants were randomly assigned to add a liter (about 33 ounces) of extra virgin olive oil per week to their Mediterranean diet, or to supplement their Mediterranean diet with 30 grams (roughly 1 ounce) per day of a mixture of walnuts, hazelnuts and almonds. Others followed a low-fat diet…. The participants followed the diets for four years, on average, according to the study.

In both groups following a Mediterranean diet, the researchers saw improvements in tests of memory and thinking compared to the group on the low-fat diet, the study showed.

Samantha Heller, a senior clinical nutritionist at New York University Medical Center in New York City, explained that “healthy fats from foods like nuts and olive oil play crucial roles in brain function and health.”

Every one of the nerve cells in the human brain is surrounded by an ultra-thin layer of fat and protein called the myelin sheath, she explained. The myelin sheath protects the nerve structure and helps nerve cell interaction. The brain gets its fats to make and maintain the myelin sheath from the foods people eat. The healthier the foods and fats, the healthier the brain, Heller said.

SOURCES: Emilio Ros, M.D., Ph.D., director, lipid clinic, Hospital Clinic, Barcelona, Spain; Sam Gandy, M.D., Ph.D., director, Center for Cognitive Health, Mount Sinai Hospital, New York City; Samantha Heller, M.S., R.D., senior clinical nutritionist, New York University Medical Center, New York City; Valls-Pedret C, Sala-Vila A, Ros E, et al. Mediterranean diet and agerelated cognitive decline. JAMA Intern Med. 2015;doi:10.1001/jamainternmed.2015.1668. [Epub ahead of print]

 The following is reprinted from an article on the American Diabetes Association website, summarizing a study published in the April 2016 issue of Diabetes Care.

What is the problem and what is known about it so far? The glycemic index, or GI, measures how much a carbohydrate-containing food raises blood glucose levels. A food with a high GI raises blood glucose more than a food with a medium or low GI. Researchers have discovered that certain types of fat affect blood glucose differently when you eat a high-GI meal.

Why did the researchers do this particular study? The researchers wanted to determine how the type of fat (or the lack of fat) eaten affects glucose levels after both a high-GI and low-GI meal.

Who was studied? A total of 13 patients with type 1 diabetes (8 women and 5 men) were recruited from the diabetes care unit of the University of Naples Federico II hospital in Naples, Italy.

How was the study done? Study participants consumed three high-GI meals in one week and then switched to three low-GI meals for an additional week. The meals had similar total carbohydrate content but were different in the amount and type of fat eaten. Meals were broken down as follows: 1) low in fat, 2) high in saturated fat (butter), and 3) high in monounsaturated fat (extra virgin olive oil). Participants’ blood glucose levels were measured continuously throughout the study weeks.

What did the researchers find? When patients ate a low-GI meal, the quality and the amount of fat did not significantly affect blood glucose levels after the meal. But when patients ate a high-GI meal, there was a rise in glucose levels soon after eating the meals with butter or low in fat. However, after the meal with extra virgin olive oil, there was no steep rise in blood glucose levels.

What were the limitations of the study? The meals were eaten at home, so the patients were not being directly monitored on what they were eating. This lack of oversight may have affected the reliability of the results. What are the implications of the study? This study shows for the fi rst time that the type of fat eaten significantly affects blood glucose levels after a high-GI meal in patients with type 1 diabetes. Avoiding foods rich in butter and using extra virgin olive oil could help improve your postprandial (after-a-meal) blood glucose levels.

Reference: Bozzetto L, Alderisio A, Giorgini M, et al. Extra-virgin olive oil reduces glycemic response to a high–glycemic index meal in patients with type 1 diabetes: a randomized controlled trial. Diabetes Care. 2016;39(4):518–524.