Researchers found that older adults who had diets similar to the Mediterranean diet or the Mediterranean-DASH diet Intervention for Neurodegeneration Delay (MIND) - which is a diet that incorporates features of the Mediterranean diet - scored significantly better on cognitive tests than those who followed less healthful diets.
Study co-author Dr. Kristine Yaffe, of the University of California, San Francisco, and colleagues recently reported their findings in the Journal of the American Geriatrics Society.
Low in junk foods and dairy products and high in fruits, vegetables, whole grains, and olive oil, the Mediterranean diet is considered one of the most healthful diets to follow.
Another diet associated with better cognitive function is the appropriately named MIND diet. This eating plan consists of 10 foods that are considered beneficial for the brain, many of which are included in the Mediterranean diet, such as vegetables, whole grains, and olive oil.
For the new study, Dr. Yaffe and colleagues set out to gain a better understanding of the link between Mediterranean-style diets and cognitive function, noting that "variation between studies makes it difficult to draw firm conclusions."
'Important public health implications'
To reach their findings, the researchers analyzed the data of 5,907 older adults who were a part of the Health and Retirement Study.
All adults completed food frequency questionnaires. The researchers used information from these questionnaires to determine how closely subjects followed a Mediterranean or MIND diet.
Participants also underwent cognitive assessments, which included tests of working memory, episodic memory, and attention.
The team found that adults who had higher adherence to the Mediterranean diet were 35 percent less likely to have poor test scores, compared with adults who followed less healthful diets.
Even older adults with moderate adherence to the Mediterranean diet were 15 percent less likely to have poor test scores, the researchers report.
Similar results were found for subjects with moderate or high adherence to the MIND diet.
Additionally, the study revealed that the incidence of cognitive impairment was lower among older adults with greater adherence to the Mediterranean or MIND diets.
According to Dr. Yaffe and colleagues, these findings indicate that a Mediterranean-style diet could protect against cognitive decline among older adults, which may "have important public health implications for preservation of cognition during aging."
"Given the limited evidence base and lack of clear dietary recommendations for cognitive health, further prospective population-based studies and clinical trials are required to elucidate the role of dietary patterns in cognitive aging and brain health," conclude the researchers.