(RxWiki News) The Mediterranean diet — with its vegetables, fruits, beans, lean meat and fish — may be heart-healthy. Add nuts and olive oil to the mix, and the brain may also get a lift.
A new study found that older patients who enhanced a Mediterranean diet with olive oil and nuts showed better functioning of the mind and memory compared to those eating a low-fat diet.
Past research has linked the Mediterranean diet to lowered cholesterol and reduced risk of heart attack, stroke and death from heart disease. Some studies have shown that this eating plan may also reduce the risk of cancer, Parkinson’s disease and Alzheimer’s disease.
This study was led by Emilio Ros, MD, of the Institut d’Investigacions Biomediques August Pi Sunyer, Hospital Clinic in Barcelona, and Ciber Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III in Madrid.
“Our results suggest that in an older population a Mediterranean diet supplemented with olive oil or nuts may counteract age-related cognitive decline,” Dr. Ros and colleagues wrote. “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.”
Patients in this study were assigned to be in one of three groups. A total of 155 followed a Mediterranean diet supplemented with extra virgin olive oil. Another 147 followed a Mediterranean diet supplemented with mixed nuts. In the control group, 145 patients ate a low-fat diet.
The average age of the patients was 67. None had heart disease at the start of the study, but they all had high-risk factors. They either had type 2 diabetes or at least three of five heart risk factors: smoking, high blood pressure, high cholesterol, overweight or obesity or family history of early-onset coronary heart disease.
After a median follow-up of about four years, Dr. Ros and team observed that patients assigned to the low-fat control diet showed a decline in mental function. Those in the nut group, however, showed improved memory compared to the control group. Those in the olive oil group showed improved attention and executive function compared to the control group. Executive function abilities are mental skills that help people complete tasks. These skills include memory, reasoning and problem-solving.
“The beneficial effect of Mediterranean diets on cognition probably stems from the abundance of antioxidants and anti-inflammatory agents that they provide,” Dr. Ros and team wrote.
Dr. Ros and colleagues stressed that olive oil and nuts may be rich in ingredients that can counteract oxidation that may harm the brain. Oxidation is a process that may cause damage or death to cells.
This study was published online May 11 in JAMA Internal Medicine.
Grants from the Instituto de Salud Carlos III funded this research. One author disclosed being a unpaid member of the scientific advisory committee of the International Nut Council. Dr. Ros received research funding and was an unpaid member of the advisory committee of the California Walnut Commission.