Because of the enormous social cost of dementia, prevention is a global public health priority. The incidence of dementia can be lowered by identifying and addressing modifiable risk factors through individualized or public health treatments. Diet is one such risk factor that can be targeted for dementia prevention and risk reduction. Healthy dietary patterns, such as the Mediterranean diet (MedDiet), have been shown in studies to be an essential strategy for lowering dementia risk. According to recent studies, increased adherence to the MedDiet is related to less cognitive deterioration. However, more research is needed because most previous studies were conducted in small cohorts with few dementia cases.
A good diet can help lower a person’s hereditary risk for dementia. However, past research on gene-diet connections has been limited, and the results have been inconsistent. Polygenic risk scores have been shown to be useful in predicting all-cause dementia and can be used to investigate potential gene-diet interactions in depth.
A new study published in the journal BMC Medicine sought to investigate the relationship between dementia incidence and MedDiet adherence, as well as the connection between genetic risk and diet for dementia.
Concerning the research
The study entailed enrolling volunteers who were 60 years of age or older, self-identified as British, Irish, or other white, and had accurate genetic and nutritional data from the UK Biobank project. The Oxford WebQ, a web-based nutritional assessment tool, was used for the dietary assessment. The MedDiet PYRAMID score and the MedDiet Adherence Screener (MEDAS) score were used to assess adherence to the MedDiet. The MEDAS score is a 14-point scale that is commonly used in observational studies and trials, whereas the PYRAMID score is a 15-point scale that is commonly used in epidemiological investigations.
Polygenic risk scores were calculated to estimate the hereditary risk of dementia. Using hospital inpatient data and mortality registries, all-cause incident dementia cases were confirmed. The diagnoses were recorded using the International Classification of Diseases (ICD) coding system. To investigate the robustness of the correlations between dementia incidence and MedDiet adherence, sensitivity analyses were performed.
The study’s findings
The study comprised 882 cases of incident all-cause dementia, according to the findings. Individuals with higher MedDiet adherence as measured by the MEDAS continuous score were mostly female, had a healthy BMI, were more physically active and had a higher educational level. The average MEDAS continuous score was 6.11.7, and the PYRAMID score was 7.51.8.
According to the MEDAS continuous and PYRAMID scores, higher adherence to the MedDiet is related to a 4.2 to 6.9 percent decreased dementia risk. Furthermore, a higher polygenic risk score has been linked to an increased risk of dementia. The sensitivity analysis results further revealed that increased MedDiet adherence was associated with a decreased dementia incidence.
As a result, the current study found that increased adherence to a MedDiet was linked to a lower incidence of dementia. The evidence for interaction with genetic risk, on the other hand, was ambiguous. This study implies that nutritional interventions, regardless of genetic propensity, will be important in the future development of dementia preventive techniques.
The study’s first restriction is that its observational approach precludes it from drawing causal inferences. Second, reduced MedDiet adherence may be a result rather than the cause of dementia. Finally, the MedDiet scores calculated may not fully match the participant’s regular food intake. Fourth, the number of dementia patients was derived solely from hospital records and death registries, which may have excluded a few cases. Finally, when compared to the broader UK population, UK Biobank members had higher socioeconomic status and were healthier.