Table 2.
Interactions of Caffeine and Age on Cognitive Functions, for All Participants, and Linear Associations of Caffeine With Cognition Median Age, Controlling for Demographic, Cardiovascular, Diabetes, Smoking, and ApoE Variables (linear contrast p values)
| Interaction of Caffeine With Age on Cognition | Entire Sample by Age Group | ||
|---|---|---|---|
| All Participants N = 638 |
Youngest Group (age 64–71.5) N = 101 |
Oldest Group (age 71.5–84) N = 84 |
|
| Overall cognition | R 2 = .375, β = .980, p = .066* | R 2 = .312, β = .033, p = .517 | R 2 = .399, β = .151, p = .002** |
| Semantic categorization | R 2 = .292, β = 1.272, p = .025** | R 2 = .270, β = .015, p = .783 | R 2 = .326, β = .163, p .001** |
| Attention/working memory | R 2 = .212, β = .305, p = .610 | R 2 = .224, β = .101, p = .065 | R 2 = .220, β = .148, p = .007** |
| Executive functioning | R 2 = .344, β = .759, p = .165 | R 2 = .234, β = .034, p = .520 | R 2 = .402, β = .135, p = .005** |
| Episodic memory | R 2 = .130, β = .573, p = .361 | R 2 = .103, β = −.059, p = .311 | R 2 = .142, β = .004, p = .938 |
Note: * trend level at >.10. **significant at .05 level.