Associations of CR1 polymorphism, education and occupation with high cognitive functioning in older adults: A Brazilian sample

Although ageing is naturally associated with cognitive decline, some lifestyle factors, such as formal education and occupational complexity, were shown to promote the preservation of cognitive functions such as memory. Genetic factors, such as the Complement Receptor 1 (CR1) gene, were also identified to have an impact on cognition. This cross-sectional study aimed to assess the associations of education, occupational complexity, and CR1 polymorphisms (rs6656401) with cognitive functions in a sample of autonomous, healthy older adults. A final sample of 102 participants was tested for executive functions, episodic memory, non-verbal memory, and reaction speed, while the final sample for the genetic assessment was 48. The mPACC scores were calculated in order to classify the participants into standard or High-Performing Older Adults. The lifelong occupations were classified according to the International Standard Classification of Occupations-08 criteria. The results revealed that education was more strongly associated with cognitive performance than occupational complexity. However, occupational complexity was independently associated with mental state among the highest education group. Furthermore, normative scores for older adults over 75 are provided. The CR1 AG/AA genotypes were associated with poorer memory performance among older participants, although these exploratory findings should be interpreted with caution due to the limited genetic sample size. The findings are consistent with the hypothesis that both education and occupation are associated with higher cognitive performance in older adults. The findings also suggest distinct cognitive effects of CR1 polymorphisms regarding ageing, although these results should be considered hypothesis-generating rather than confirmatory.