According to a new study, overweight or obese people of advanced age with a higher adherence to the Mediterranean diet maintain their cognitive performance and improve their skills even after three years.
Not only does the Mediterranean diet have positive effects on the cardiovascular health of those who follow it, but it can also help them improve their memory and prevent or delay the effects of cognitive deterioration related to aging. However, these beneficial effects are not perceived equally by everyone, which leads to the questioning of the type of interventions based on dietary recommendations in order to adapt them to the individual characteristics of each person. These are the key findings of a study published in Clinical Nutrition, carried out by researchers from the Research Group on Integrated Pharmacology and Systemic Neuroscience and the Research Group on Cardiovascular Risks and Nutrition of the Instituto Hospital del Mar for Medical Research (IMIM-Hospital del Mar) by the group for Psychology and Mental Health of the Biomedical Research Institute of Bellvitge (IDIBELL) and Bellvitge University Hospital, all from the Obesity Physiopathology and Nutrition Group, CIBEROBN. The University of Valencia, the University of Rivira i Virgili and the University of Navarra were also part of the research.
The study tracked a group of 487 volunteers, practically half of whom were men and half were women, and had a mean age of 65, for three years. They all took part in the PREDIMED-PLUS study, a multicenter study involving 23 Spanish research centers that analyzes the effect of the traditional Mediterranean diet with energetic restrictions, promoting physical activity and behavioral interventions, on weight loss and prevention of cardiovascular disease -Diseases. At the start of the study, participants were overweight or obese and met at least three metabolic syndrome criteria, including high blood pressure, hyperglycemia, excess fat around the waist, low HDL cholesterol, and high triglycerides. Metabolic syndrome is very common, affects almost one in four adults worldwide, and carries a higher risk of heart disease, cerebrovascular accidents, type 2 diabetes, and cognitive deterioration.
Improved adherence to the diet improves memory
The researchers used neuropsychological tests to analyze the cognitive status of the volunteers at the start of the study and one and three years later. The researchers noted their performance in relation to memory and other cognitive functions, including the ability to make decisions, think, pay attention, plan, or ignore certain impulses.
According to previous studies, people with metabolic syndrome who did not follow any intervention would have reduced their global cognition by almost 0.4 points and their memory by 0.1 within three years. However, with the study’s recommendations, they saw improvements of over 0.6 points in global cognition and nearly 0.9 in memory. The units used to measure cognition were standardized in order to be able to compare different neuropsychological tests.
For the patient group, the results show a direct relationship between adherence to the Mediterranean diet and cognitive improvement. Compliance with a low-calorie Mediterranean diet was measured with a survey of 17 points, which examined, among other things, the consumption of extra virgin olive oil and the number of fruit and vegetable rations consumed daily. Values above 11 points are considered to be a high adherence to the Mediterranean diet. Thus, for each point of improvement in compliance with this type of diet, memory improved by 0.12 points. According to research, this improvement may be due to weight loss and an increase in physical activity, which is also linked to an improved quality of life. With that in mind, Rafael de la Torre, one of the study’s lead researchers, says this is “important when you consider that people may not notice cognitive changes, but they can be more relevant when combined with improvements in their quality of life”.
Meanwhile, Fernando Fernández-Aranda, head of the project at IDIBELL and Bellvitge Hospital, says that “thanks to this study, we have identified the benefits of the Mediterranean diet beyond weight loss, such as verbal memory and attention, which clearly benefit from it”.
Not everyone has the same benefits, according to Natàlia Soldevila-Domènech, first signatory to the study. Women, the elderly, those with a lower level of education, and those with type 2 diabetes benefit least from the Mediterranean diet. In this context, she says that “despite the fact that women have fewer cognitive improvements than men, these improvements occurred in all participants. Everyone benefits from the Mediterranean diet, only some more than others. “
Meanwhile, the volunteers with the lowest cognitive performance in memory and other cognitive functions at the start of the study had the least adherence to the Mediterranean diet and those with the least chance of achieving significant weight loss. “We wanted to know which volunteers lost weight and which did not, and why, from a cognitive and behavioral point of view, some did and some did not,” explains Rafael de la Torre. In particular, those who had the best auditory memory, higher planning and decision-making skills, shorter reaction times, and less impulsiveness at the start of the study, achieved the study goal of 8% of their weight over the three years. According to research, this is because most people with these cognitive abilities had high adherence to the low-calorie Mediterranean diet, resulting in clinically relevant weight loss.
For these reasons, the results obtained must enable the authors to identify the groups with the greatest difficulty in benefiting from these lifestyle interventions, to adapt the measures and thus to facilitate them in the adoption of the proposed guidelines for a healthy life, i.e. also to help cognitive ones To prevent degradation.
The study was funded by national research agencies, including the Carlos III Health Institute and the Government of Catalonia, as well as European funds (Eat2BeNice project).
Soldevila-Domenech, N., et al. (2021) Interaction between cognition and weight loss in people following a Mediterranean diet: three-year follow-up of the PREDIMED-Plus study. Clinical nutrition. doi.org/10.1016/j.clnu.2021.07.020.