Mediterranean Diet Improves Cognition
Objective Previous observational studies reported beneficial effects of the Mediterranean diet (MedDiet) on cognitive function, but results were inconsistent. We assessed the effect on cognition of a nutritional intervention using MedDiets in comparison with a low-fat control diet.
Methods We assessed 522 participants at high vascular risk (44.6% men, age 74.6 ± 5.7 years at cognitive evaluation) enrolled in a multicentre, randomised, primary prevention trial (PREDIMED), after a nutritional intervention comparing two MedDiets (supplemented with either extra-virgin olive oil (EVOO) or mixed nuts) versus a low-fat control diet. Global cognitive performance was examined by Mini-Mental State Examination (MMSE) and Clock Drawing Test (CDT) after 6.5 years of nutritional intervention. Researchers who assessed the outcome were blinded to group assignment. We used general linear models to control for potential confounding.
Results After adjustment for sex, age, education, Apolipoprotein E genotype, family history of cognitive impairment/dementia, smoking, physical activity, body mass index, hypertension, dyslipidaemia, diabetes, alcohol and total energy intake, participants allocated to the MedDiet+EVOO showed higher mean MMSE and CDT scores with significant differences versus control (adjusted differences: +0.62 95% CI +0.18 to +1.05, p=0.005 for MMSE, and +0.51 95% CI +0.20 to +0.82, p=0.001 for CDT). The adjusted means of MMSE and CDT scores were also higher for participants allocated to the MedDiet+Nuts versus control (adjusted differences: +0.57 (95% CI +0.11 to +1.03), p=0.015 for MMSE and +0.33 (95% CI +0.003 to +0.67), p=0.048 for CDT). These results did not differ after controlling for incident depression.
Conclusions An intervention with MedDiets enhanced with either EVOO or nuts appears to improve cognition compared with a low-fat diet.
ISRCTN:35739639
Worldwide prevalence of dementia is expected to reach 65.7 million and 115.4 million in 2030 and 2050, respectively. Currently, there is no effective therapy to delay the onset or halt the progression of dementia, a growing public health problem with priority for research.
The potential protection on cognition has been examined for some nutrients such as fatty acids, vitamins, fish, fruit and vegetables but observational and experimental studies have provided inconsistent results. Defining the effect of diet on health by the overall dietary pattern instead of a single or a few nutrients allows to study the synergy among nutrients and avoids problems due to confounding, multiple testing and collinearity among them.
The Mediterranean diet (MedDiet) is characterised by the use of olive oil as the main culinary fat and high consumption of plant-based foods (fruits and nuts, vegetables, legumes and minimally processed cereals). It also includes moderate-to-high consumption of fish and seafood and low consumption of butter or other dairy products and meat or meat products. Regular but moderate intake of alcohol, preferentially red wine during meals, is customary.
The relationship between conformity with the MedDiet and cognition has been assessed in observational studies with promising, though not fully consistent, results. The only available trial evaluating this topic found inconsistent results and it had an inordinately short follow-up of only 10 days. We evaluated global cognition among subjects participating in a long-term prevention randomised trial that compared two interventions with MedDiet versus a low-fat diet.
Abstract and Introduction
Abstract
Objective Previous observational studies reported beneficial effects of the Mediterranean diet (MedDiet) on cognitive function, but results were inconsistent. We assessed the effect on cognition of a nutritional intervention using MedDiets in comparison with a low-fat control diet.
Methods We assessed 522 participants at high vascular risk (44.6% men, age 74.6 ± 5.7 years at cognitive evaluation) enrolled in a multicentre, randomised, primary prevention trial (PREDIMED), after a nutritional intervention comparing two MedDiets (supplemented with either extra-virgin olive oil (EVOO) or mixed nuts) versus a low-fat control diet. Global cognitive performance was examined by Mini-Mental State Examination (MMSE) and Clock Drawing Test (CDT) after 6.5 years of nutritional intervention. Researchers who assessed the outcome were blinded to group assignment. We used general linear models to control for potential confounding.
Results After adjustment for sex, age, education, Apolipoprotein E genotype, family history of cognitive impairment/dementia, smoking, physical activity, body mass index, hypertension, dyslipidaemia, diabetes, alcohol and total energy intake, participants allocated to the MedDiet+EVOO showed higher mean MMSE and CDT scores with significant differences versus control (adjusted differences: +0.62 95% CI +0.18 to +1.05, p=0.005 for MMSE, and +0.51 95% CI +0.20 to +0.82, p=0.001 for CDT). The adjusted means of MMSE and CDT scores were also higher for participants allocated to the MedDiet+Nuts versus control (adjusted differences: +0.57 (95% CI +0.11 to +1.03), p=0.015 for MMSE and +0.33 (95% CI +0.003 to +0.67), p=0.048 for CDT). These results did not differ after controlling for incident depression.
Conclusions An intervention with MedDiets enhanced with either EVOO or nuts appears to improve cognition compared with a low-fat diet.
ISRCTN:35739639
Introduction
Worldwide prevalence of dementia is expected to reach 65.7 million and 115.4 million in 2030 and 2050, respectively. Currently, there is no effective therapy to delay the onset or halt the progression of dementia, a growing public health problem with priority for research.
The potential protection on cognition has been examined for some nutrients such as fatty acids, vitamins, fish, fruit and vegetables but observational and experimental studies have provided inconsistent results. Defining the effect of diet on health by the overall dietary pattern instead of a single or a few nutrients allows to study the synergy among nutrients and avoids problems due to confounding, multiple testing and collinearity among them.
The Mediterranean diet (MedDiet) is characterised by the use of olive oil as the main culinary fat and high consumption of plant-based foods (fruits and nuts, vegetables, legumes and minimally processed cereals). It also includes moderate-to-high consumption of fish and seafood and low consumption of butter or other dairy products and meat or meat products. Regular but moderate intake of alcohol, preferentially red wine during meals, is customary.
The relationship between conformity with the MedDiet and cognition has been assessed in observational studies with promising, though not fully consistent, results. The only available trial evaluating this topic found inconsistent results and it had an inordinately short follow-up of only 10 days. We evaluated global cognition among subjects participating in a long-term prevention randomised trial that compared two interventions with MedDiet versus a low-fat diet.