In many cases, memory loss can be improved and cognitive deterioration can be halted or slowed down, the team of Spanish researchers found.
We found that participants experienced small-to-moderate significant improvements in several cognitive domains after three years of Mediterranean diet intervention.
While the Mediterranean diet has proven cardiovascular and cognitive health benefits for any individual, not all patients – especially older ones – benefit at the same level or in the same way. This suggests the need for highly-targeted dietary recommendations.See Also: Health News
According to the researchers, the new study refines the understanding of correlations between cognitive performance and weight loss, adding further evidence to the cognitive benefits associated with a better adherence to the MedDiet.
“We studied the within-subject longitudinal relationships between cognition, body mass index, physical activity and quality of life in older adults following a MedDiet,” the researchers wrote.
By focusing on a sample of 487 male and female volunteers, who on average were 65 years old, the study’s authors have found measurable improvements due to the MedDiet. All subjects took part in the Predimed-Plus trial, a major study to which dozens of Spanish research centers contributed that focused on the effects of the MedDiet on a healthy lifestyle.
“At baseline, participants were overweight or obese and had at least three criteria for metabolic syndrome, including hypertension, hyperglycemia, excess waist fat, low HDL cholesterol and high triglyceride levels,” a press release reads.
“We found that participants experienced small-to-moderate significant improvements in several cognitive domains after three years of Mediterranean diet intervention,” Natalia Soldevila-Domenech, a neuroscience researcher at the Hospital Del Mar Medical Research Institute in Barcelona, told Olive Oil Times.
Improvements included short and long-term spatial and visual memory as well as verbal memory, abilities to move and act, the degree of attention and of inhibition.
“Cognitive scores were then grouped into memory, executive functions and global cognition constructs,” Soldevila-Domenech said. “We observed memory changes correlated with weight reductions after one year and with improvements in physical activity after three years.”
“Higher adherence to the MedDiet enhanced memory changes,” she added. “Finally, improvements in executive functions and global cognition were coupled with improvements in the quality of life of participants.”
Researchers found that cognitive benefits for the subject adhering to the MedDiet were observed in all participants, independent of their weight, gender, age, education level, intelligence quotient, smoking status, diagnostic of diabetes or pre-diabetes and the use of some medications, including tranquilizers, sedatives or treatments for high cholesterol.
“These results are important since the population included in the study were older adults with overweight or obesity and metabolic syndrome,” Rafael de la Torre, a professor at the Neurosciences Research Program in Barcelona, told Olive Oil Times.
“Without any intervention, individuals with these cardiovascular characteristics should have presented a cognitive decline over time, as result of aging, and in this study their cognition improved independently of their underlying pathological condition,” he added.
The scientists also noted that cognitive improvements were more evident in men, in younger individuals and in subjects with higher educational level and higher MedDiet adherence.See Also: Mediterranean Diet May Prevent Memory Loss and Dementia Symptoms
“In turn, women, older subjects, those with lower education, diabetes or those that used tranquilizers or sedatives presented smaller cognitive changes,” de la Torre said.
However, the reasons behind these differences are yet to be fully explored.
“Although gender is known to be an important aspect when considering cognition, there is a lack of studies investigating gender-specific effects on the response to lifestyle interventions,” de la Torre said. “In the case of diabetes, it is considered a risk factor for dementia and lower cognitive performance due to the harmful effects of poor glycemic control.”
Researchers emphasized that dietary recommendations focused on promoting the consumption of virgin olive oil, nuts – especially walnuts – fruits and vegetables, whole grains, fiber-rich foods and low-fat yogurts, which have been consistently associated with weight loss or lower weight gain and reduced risk of obesity-related illnesses.
“On the other hand, dietary recommendations also encourage participants to reduce the consumption of sugar-sweetened beverages, fast foods, refined grain products, white rice, pasta (except for whole-grain pasta), French fries, potatoes, trans fats, sweets, cakes, pies, sugar, precooked meals, sausages or cold cuts of processed meats, and pâté, which have been consistently associated with weight gain,” Soldevila-Domenech said. “Therefore, the intervention laid in the diet’s overall quality instead of the relative macronutrient content.”
Extra virgin olive oil was the main source of dietary fat among volunteers who showed cognitive improvements after three years of study. All of the volunteers were provided with an allotment of extra virgin olive oil – one liter per month – and occasionally almonds, to promote the MedDiet and encourage compliance with the trial.
While participants were given an energy-restricted MedDiet with recommendations to perform physical activities and focus on weight loss goals, the control group followed an energy-unrestricted MedDiet with no promotion of such goals or activities.
“Therefore, we observed that individual changes in cognition were not uniform among participants despite belonging to the same intervention group,” Soldevila-Domenech said. “Unraveling these differences between individuals in terms of cognitive change is crucial for understanding the impact of preventive interventions for cognitive decline.”
According to the researchers, the high content of plant-based foods in the MedDiet, along with fish and moderate red wine consumption during meals, “make the MedDiet rich in phenolic compounds, N‑3 polyunsaturated fatty acids and vitamins that, in conjunction, may contribute to reduced oxidative stress and chronic inflammation and better neurovascular health, which may explain the observed cognitive changes.”
“Future research should explore the underlying mechanism that explains the observed gender differences, and gender-specific designs should be explored in future intervention studies,” de la Torre said.
“Our results also suggest that lifestyle interventions for weight loss should consider the cognitive profile of participants in order to adapt them to individual’s cognitive characteristics and needs, particularly to those with obesity exhibiting a dysexecutive profile,” he added.
“We believe that prevention studies with a Mediterranean diet where one-size-fits-all are precluded, we have to have to move to a more personalized approach,” de la Torre concluded.