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Study shows link between negative age stereotypes, Alzheimer’s disease brain changes

Longitudinal analysis of dementia-free, older adults indicated those with more negative age stereotypes had more significant brain changes related to Alzheimer’s disease, compared with those with positive age stereotypes.

“Although negative age stereotypes have been found to predict a number of adverse outcomes among older individuals, it was unknown whether the influence of the stereotypes extended to brain structure and pathology,” Becca R. Levy, PhD, of Yale University, and colleagues wrote. “As premised by stereotype embodiment theory, age stereotypes assimilated from a diversity of sources in the culture at a younger age can impact physiological and cognitive outcomes in later life when these stereotypes become self-relevant.”

Researchers conducted two studies among participants in the Baltimore Longitudinal Study of Aging to assess associations between age stereotypes and brain changes related to Alzheimer’s disease. Study participants (n = 52) were dementia-free and had a mean age of 68.54 years at first MRI assessment. They underwent yearly MRI assessments for 10 years. Negative age stereotypes were assessed via the 16-item age-stereotype subscale of the Baltimore Longitudinal Study of Aging’s Attitudes towards Old People Scale starting in 1968.

Results from the first study indicated individuals with more negative age stereotypes had significantly greater decreases in hippocampal volume when adjusting for age, sex, education, self-rated health, well-being, number of chronic conditions and intracranial volume.

Hippocampal volume decline was three times greater among individuals with negative age stereotypes compared with those with more positive age stereotypes.

“Participants holding more-negative age stereotypes tended to have the same hippocampal-volume decline in 3 years that participants holding more-positive age stereotypes tended to have in 9 years,” according to researchers.

Results from the second study indicated individuals with more negative age stereotypes had significantly higher composite-plaques-and-tangles scores compared with those with more positive age stereotypes in adjusted analysis.

Findings from both studies were not influenced by outliers, according to researchers.

“The current study is the first to demonstrate that a culture-based risk factor predicts the development of Alzheimer’s disease-related pathological changes in the brain. This finding provides a basis for reinterpreting Alzheimer’s disease data. To illustrate, diet, a previously established environmental factor, has been posited as an explanation for why the rate of Alzheimer’s disease in the United States is five times that of India. Alternatively, this discrepancy might be explained by a comparison of those two cultures from which age stereotypes are derived: India has a tradition of venerating elders, whereas the United States has a prevalence of negative age stereotypes,” the researchers concluded. – by Amanda Oldt

Disclosure: Please see the full study for a list of all authors’ relevant financial disclosures.