Project Summary/Abstract
An estimated 5.2 million older Americans had Alzheimer's disease in 2016. As the population of the United States
ages, the number of dementia cases is projected to reach 13.8 million by 2050, with high costs for the health
care system and society. It is critical to identify modifiable behavioral factors that slow (or accelerate) age-related
and pathological cognitive decline. Alcohol consumption is one such behavior that has extensive consequences
for cognitive functioning. Although alcohol dependence and abuse may lead to structural and functional brain
damage, epidemiological studies suggest a possible protective effect of light-to-moderate alcohol consumption
in aging populations. Alcohol, however, may not benefit everyone who drinks moderately, especially when
individuals reach older ages. In addition to the effect of alcohol on cognition, individual differences in cognitive
functioning may predict the level of alcohol consumed. Impaired vs. preserved cognitive performance may be
both a consequence and predictor of alcohol use. Yet, this reciprocity is neglected in studies of older adults.
Most work has focused either on younger or older samples, or treated age as a confounder. The proposed
research is the first systematic attempt to examine the reciprocal, synergistic effect of alcohol
consumption and cognition by adopting a developmental aging perspective. The specific aims of this
research are (1) to identify the reciprocal, longitudinal association between alcohol consumption and cognition,
(2) to examine whether this association varies by age, and (3) to test patterns of alcohol consumption and
dependence in older adulthood as risk factors for incident cognitive impairment and dementia. This research will
leverage individual participant data (IPD) from four well-established national and international longitudinal
cohorts that have at least two repeated measures of alcohol consumption (frequency and quantity) and cognition,
spanning from middle adulthood to very old age. The proposed IPD analyses will provide unprecedented insights
into the reciprocal relation between alcohol consumption and cognition, and how this bidirectional association
changes with advancing age. It will lay the groundwork for future studies on the development of effective
interventions targeted at enhancing cognition and promoting healthy aging.