Do the effects of APOE-ε4 on cognitive function and decline depend upon vitamin status? MacArthur Studies of Successful Aging.

OBJECTIVES

To investigate whether gene nutrient interactions influence the risk of cognitive dysfunction among older persons.

DESIGN

We performed a cross-sectional and longitudinal study of 499 adults aged 70-79 years from the Mac Arthur Study of Successful Aging to determine the effect of apolipoprotein E (APOE) in conjunction with plasma levels of homocysteine and of the related B vitamins on multiple domains of cognitive function and cognitive decline.

RESULTS

The APOE-ε4 allele, high homocysteine, low folate, and low vitamin B6 levels were each associated with worse baseline cognitive function, and all but B6 and B12 were associated with seven year cognitive decline. There was no interaction between APOE-ε4, and homocysteine, folate, B6, or B12 in predicting baseline cognitive function (p-values: 0.12-0.94) or longitudinal decline (p-values: 0.52-0.91). Of five cognitive subtests, there was a significant interaction between the ε4 allele, low B6, and decline in correct naming response items (p=0.04).

CONCLUSION

B vitamin status does not influence the risk of overall cognitive dysfunction in ε4 allele affected older adults.