APOE E4 status predicts age-related cognitive decline in the ninth decade: longitudinal follow-up of the Lothian Birth Cohort 1921.

Carriers of the APOE E4 allele have an increased risk of developing Alzheimer's disease. However, it is less clear whether APOE E4 status may also be involved in non-pathological cognitive ageing. The present study investigated the associations between APOE genotypes and cognitive change over 8 years in older community-dwelling individuals. APOE genotype was determined in 501 participants of the Lothian Birth Cohort 1921, whose intelligence had been measured in childhood in the Scottish Mental Survey 1932. A polymorphic variant of TOMM40 (rs10524523) was included to differentiate between the effects of the APOE E3 and E4 allelic variants. Cognitive performance on the domains of verbal memory, abstract reasoning and verbal fluency was assessed at mean age 79 years (n=501), and again at mean ages of 83 (n=284) and 87 (n=187). Using linear mixed models adjusted for demographic variables, vascular risk factors and IQ at age 11 years, possession of the APOE E4 allele was associated with a higher relative rate of cognitive decline over the subsequent 8 years for verbal memory and abstract reasoning. Individuals with the long allelic variant of TOMM40, which is linked to APOE E4, showed similar results. Verbal fluency was not affected by APOE E4 status. APOE E2 status was not associated with change in cognitive performance over 8 years. In non-demented older individuals, possession of the APOE E4 allele predicted a higher rate of cognitive decline on tests of verbal memory and abstract reasoning between 79 and 87 years. Thus, possession of the APOE E4 allele may not only predispose to Alzheimer's disease, but also appears to be a risk factor for non-pathological decline in verbal memory and abstract reasoning in the ninth decade of life.

MTHFR polymorphisms and cognitive ageing in the ninth decade: the Lothian Birth Cohort 1921.

Low blood levels of B vitamins have been implicated in age-associated cognitive impairment. The present study investigated the association between genetic variation in folate metabolism and age-related cognitive decline in the ninth decade of life. Both the 677C>T (rs1801133) polymorphism and the scarcely studied 1298A>C (rs1801131) polymorphism of the MTHFR gene were assessed in relation to cognitive change over 8 years in older community-dwelling individuals. MTHFR genotype was determined in 476 participants of the Lothian Birth Cohort 1921, whose intelligence was measured in childhood in the Scottish Mental Survey of 1932. Cognitive performance on the domains of verbal memory, reasoning and verbal fluency was assessed at mean age of 79 (n = 476) and again at mean ages of 83 (n = 275) and 87 (n = 180). Using linear mixed models, the MTHFR 677C>T and 1298A>C variants were not associated with the rate of cognitive change between 79 and 87 years, neither in the total sample, nor in a subsample of individuals with erythrocyte folate levels below the median. APOE E4 allele carrier status did not interact with MTHFR genotype in affecting change in cognitive performance over 8 years. No significant combined effect of the two polymorphisms was found. In conclusion, MTHFR 677C>T and 1298A>C polymorphisms were not associated with individual change in cognitive functioning in the ninth decade of life. Although polymorphisms in the MTHFR gene may cause disturbances in folate metabolism, they do not appear to be accompanied by changes in cognitive functioning in old age.

Fish consumption, not fatty acid status, is related to quality of life in a healthy population.

Depressive symptoms in the community have a considerable impact on quality of life. Although long-chain polyunsaturated fatty acids (LCPUFA) have frequently been implicated in depressed mood, their relationship with quality of life has scarcely been investigated. This study examined the cross-sectional associations between fish consumption and plasma phospholipid LCPUFA status on the one hand, and quality of life, as measured by the Short Form 36 questionnaire, on the other in a population-based sample. The mental health component of quality of life was not associated with LCPUFA status or fish consumption. Fish consumption showed a positive association with physical well-being, which remained significant after correction for LCPUFA status, suggesting that the relationship between fish consumption and physical well-being is independent of the LCPUFA content of fish. These findings indicate that fish consumption may serve as a proxy for a healthy lifestyle or a favorable nutritional status, which is reflected in better quality of life.