Reclassifying wine intake reshapes the Mediterranean diet’s cognitive impact

By Priyanjana Pramanik, MSc.Reviewed by Susha Cheriyedath, M.Sc.Nov 17 2025

Scoring wine as a benefit in Mediterranean diet tools may blur important diet–cognition patterns, while reverse scoring reveals modest links with better cognitive screening scores in older adults at high risk of dementia.

Study: Challenging the Wine Component in Mediterranean Diet Scores: Cognitive Outcomes in Portuguese Adults at High Risk of Dementia. Image Credit: doganyavas / Shutterstock

A recent study in the journal Nutrients examined how two methods of measuring adherence to the Mediterranean diet influence the link between diet adherence and cognitive performance among older adults in Portugal.

The two methods differ in how wine consumption is scored. No significant relationship was observed when wine was considered beneficial, but when wine consumption was reverse-scored, higher adherence was linked with better cognitive performance.

Mediterranean Diet Characteristics and Alcohol Scoring Challenges

The Mediterranean diet is a culturally rooted, plant-forward eating pattern recognized globally for its health benefits. It emphasizes fruits, vegetables, legumes, nuts, whole grains, and extra-virgin olive oil, with moderate intake of fish, white meat, and dairy, and limited consumption of sweets and red or processed meats.

Traditionally, small amounts of wine are consumed with meals. As Europe experiences rapid population aging, particularly in Portugal, where the aging index is among the highest, age-related cognitive decline has become a major public health concern.

Evidence Linking Mediterranean Diet and Cognitive Health

Evidence from various international cohorts suggests that greater adherence to the Mediterranean diet is associated with reduced risk of chronic disease and better cognitive outcomes, including improved memory, global cognition, and physical function in older adults. However, most studies do not include Portuguese participants and often rely on a single cognitive test, which limits the depth of assessment.

A further complication is the inconsistent scoring of wine consumption in the Mediterranean Diet Adherence Screener. While the original version awards points for moderate wine intake, a Portuguese telephone-validated version reverses this scoring. 

These discrepancies are notable because emerging research suggests that even low levels of alcohol may exert neurotoxic effects. To address these issues, researchers evaluated how different ways of scoring wine intake may influence associations between the Mediterranean diet and cognitive function in Portuguese older adults at elevated dementia risk.

Participant Recruitment and Eligibility Criteria

Researchers used cross-sectional data collected between January and May 2023 in Porto, Portugal. The participant group consisted of 75 adults aged 55 to 85 years who had an elevated risk of dementia, as determined by the Cardiovascular Risk Factors, Aging, and Dementia score.

Additional eligibility criteria included at least four years of education and a cognitive score above age- and education-adjusted thresholds. Individuals with dementia, major disability, participation-limiting conditions, or insufficient autonomy in daily activities were excluded. Ethical approval was obtained from the relevant regional authorities.

Cognitive Assessment Tools and Impairment Definitions

Cognitive function was measured by trained interviewers using three validated tools: the Montreal Cognitive Assessment, the Addenbrooke Cognitive Examination Revised, and the Mini-Mental State Examination. Probable cognitive impairment was defined as performance less than 1.5 standard deviations below normative values for age and education.

Mediterranean Diet Scoring Using Original and Reverse Wine Approaches

Mediterranean diet adherence was assessed using the 14-item Mediterranean Diet Adherence Screener in two scoring formats. The original version awards a point for moderate wine intake, defined as 7 to 14 glasses per week.

The revised reverse-scored version awards a point for drinking less than one portion of wine daily. Sociodemographic and lifestyle factors were collected using structured questionnaires. Group comparisons used chi-square, Fisher’s exact, Mann-Whitney, or Kruskal-Wallis tests.

Associations between diet scores and cognitive outcomes were examined using analysis of covariance models adjusted for age, sex, body mass index, education, and physical activity, with cognitive scores log-transformed due to non-normality.

Participant Characteristics and Lifestyle Profiles

The participant group, comprising 75 adults, was predominantly female and had an average age of 70 years. One-third were overweight and one-fifth were obese. Most had at least ten years of education, and over half reported monthly incomes above two thousand euros.

Few currently smoked or engaged in regular moderate-to-vigorous physical activity. Using the original Mediterranean diet scoring, only 17 percent achieved high adherence, but this increased to 33 percent when wine intake was reverse-scored. Dietary adherence was not significantly associated with any sociodemographic or lifestyle factor.

Cognitive Outcomes and Sociodemographic Associations

Probable cognitive impairment was detected in approximately 9% of participants using the Montreal Cognitive Assessment and the Addenbrooke's Cognitive Examination Revised, but in more than half of participants using the Mini-Mental State Examination.

The study suggests that this discrepancy may reflect the higher sensitivity of the Mini-Mental State Examination to mood-related factors such as anxiety, which are more common in women who represented the majority of the sample.

Higher education, higher income, and non-smoking status were consistently associated with better cognitive performance, whereas age was associated only with Addenbrooke Cognitive Examination Revised scores. Sex, body mass index, and physical activity were not significantly related to cognitive outcomes.

Associations Between Diet Scoring Methods and Cognitive Measures

In adjusted models, original Mediterranean diet scores were not linked with performance on any cognitive test. The reverse-scored version showed a borderline association with Montreal Cognitive Assessment performance and a significant positive association with Mini-Mental State Examination scores.

Among all covariates, education accounted for the largest proportion of variance in cognitive outcomes, contributing between 18% and 35%.

Interpretation of Wine Scoring Effects on Diet and Cognition

The study found no relationship between Mediterranean diet adherence and cognition when using the original scoring; however, reversing the wine item produced a modest association with Mini-Mental State Examination performance, suggesting that the scoring of alcohol meaningfully influences the findings.

The use of multiple cognitive measures and careful adjustment for confounders are strengths of this work. However, limitations include a small sample, reliance on volunteers, limited statistical power, a cross-sectional design, and dependence on screening tools rather than full neuropsychological batteries. 

Overall, the results suggest that treating wine as beneficial may obscure important relationships between diet and cognition, highlighting the need for larger studies to refine dietary assessment tools for aging research.