Background: Evidence from prospective epidemiologic studies and animal models suggests that intakes of dietary fats and copper may be associated with neurodegenerative diseases.
Objective: To examine whether high dietary copper intake is associated with increased cognitive decline among persons who also consume a diet high in saturated and trans fats.
Design: Community-based prospective study.
Setting: Chicago, Ill. Patients Chicago residents 65 years and older.
Main outcome measures: Cognitive function was assessed using 4 cognitive tests administered during in-home interviews at 3-year intervals for 6 years. Dietary assessment was performed with a food frequency questionnaire. Dietary intakes of copper and fats were related to change in global cognitive score (the mean of the 4 tests) among 3718 participants.
Results: Among persons whose diets were high in saturated and trans fats, higher copper intake was associated with a faster rate of cognitive decline. In multiple-adjusted mixed models, the difference in rates for persons in the highest (median, 2.75 mg/d) vs lowest (median, 0.88 mg/d) quintiles of total copper intake was -6.14 standardized units per year (P<.001) or the equivalent of 19 more years of age. There was also a marginally statistically significant association (P = .07) with the highest quintile of food intake of copper (median, 1.51 mg/d) and a strong dose-response association with higher copper dose in vitamin supplements. Copper intake was not associated with cognitive change among persons whose diets were not high in these fats.
Conclusion: These data suggest that high dietary intake of copper in conjunction with a diet high in saturated and trans fats may be associated with accelerated cognitive decline.