Studies have been carried out investigating the potential benefits of Mediterranean diet on brain functions and ability to prevent cognitive decline, and a new study strengthens these findings adding that supplementing such a diet with antioxidant-rich extra virgin olive oil or mixed nuts goes a long way in improving cognitive function in a study of older adults.
Dietary habits have been linked to cognitive abilities and there have been evidence that Oxidative stress plays a major role in cognitive decline. In a new study, Emilio Ros, M.D., Ph.D., of the Institut d’Investigacions Biomediques August Pi Sunyer, Hospital Clinic, Barcelona, and Ciber Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, along with other researchers compared a Mediterranean diet supplemented with olive oil or nuts with a low-fat control diet.
In the randomized clinical trial that included 447 cognitively healthy volunteers with an average age of nearly 67 years out of which 223 were women. The volunteers were at high cardiovascular risk and were enrolled in the Prevencion con Dieta Mediterranea nutrition intervention.
Of the participants, 155 individuals were assigned to supplement a Mediterranean diet with one liter of extra virgin olive oil per week; 147 were assigned to supplement a Mediterranean diet with 30 grams per day of a mix of walnuts, hazelnuts and almonds; and 145 individuals were assigned to follow a low-fat control diet.
The authors measured cognitive change over time with a battery of neuropsychological tests and they constructed three cognitive composites for memory, frontal (attention and executive function) and global cognition. After a median of four years of the intervention, follow-up tests were available on 334 participants.
At the end of the follow-up, there were 37 cases of mild cognitive impairment: 17 (13.4 per cent) in the Mediterranean diet plus olive oil group; eight (7.1 per cent) in the Mediterranean diet plus nuts group; and 12 (12.6 per cent) in the low-fat control group. No dementia cases were documented in patients who completed study follow-up.
The study found that individuals assigned to the low-fat control diet had a significant decrease from baseline in all composites of cognitive function. Compared with the control group, the memory composite improved significantly in the Mediterranean diet plus nuts, while the frontal and global cognition composites improved in the Mediterranean diet plus olive oil group. The authors note the changes for the two Mediterranean diet arms in each composite were more like each other than when comparing the individual Mediterranean diet groups with the low-fat diet control group.
“Our results suggest that in an older population a Mediterranean diet supplemented with olive oil or nuts may counter-act age-related cognitive decline. The lack of effective treatments for cognitive decline and dementia points to the need of preventive strategies to delay the onset and/or minimize the effects of these devastating conditions. The present results with the Mediterranean diet are encouraging but further investigation is warranted,” the study concludes.
Mediterranean diet cuts heart disease risk by half
A recent study conducted in Greece at Harokopio University in Athens says that Adults who closely followed the Mediterranean diet were 47 per cent less likely to develop heart disease over a 10-year period compared to similar adults who did not closely follow the diet.
The study is based on a representative sample of more than 2,500 Greek adults, ages 18 to 89, who provided researchers with their health information each year from 2001 to 2012. Participants also completed in-depth surveys about their medical records, lifestyle and dietary habits at the start of the study, after five years and after 10 years.
Overall, nearly 20 per cent of the men and 12 per cent of the women who participated in the study developed or died from heart disease, a suite of conditions that includes stroke, coronary heart disease caused by the buildup of plaque in the heart’s arteries, acute coronary syndromes such as heart attack, and other diseases. Other studies have shown Greeks and Americans have similar rates of heart disease and its risk factors.
The researchers scored participants’ diets on a scale from 1 to 55 based on their self-reported frequency and level of intake for 11 food groups. Those who scored in the top-third in terms of adherence to the Mediterranean diet, indicating they closely followed the diet, were 47 percent less likely to develop heart disease over the 10-year follow-up period as compared to participants who scored in the bottom-third, indicating they did not closely follow the diet. Each one-point increase in the dietary score was associated with a 3 per cent drop in heart disease risk.
While there is no set Mediterranean diet, it commonly emphasizes fresh fruits and vegetables, whole grains, beans, nuts, fish, olive oil and even a glass of red wine.