Table 3.

Interactions of Caffeine and Age on Brain Volume, for MRI Sample, and Linear Associations of Caffeine With Brain Volume by Median Age, Controlling for Demographic, Cardiovascular, Diabetes, Smoking, and ApoE Variables

	Interaction of Caffeine With Age on Brain Volume	MRI Sample by Median Age
	MRI Sample N = 185	Youngest Group (age 64–71.5) N = 101	Oldest Group (age 71.5–84) N = 84
Gray matter	R 2 = .716, β = 1.694, p = .034*	R 2 = .550, β = −.064, p = .309	R 2 = .580, β = .198, p = .033*
White matter	R 2 = .861, β = −.422, p = .448	R 2 = .865, β = .014, p = .745	R 2 = .866, β = −.032, p = .536

Note: MRI = Magnetic resonance imaging.

*Significant at .05 level.