Table 3.

Telomere length as it relates to caffeine intake and coffee consumption in U.S. adults, separated by coffee drinking status, after adjusting for the covariates

	Telomere length (base pairs)
Exposure variable	Regression
Sample	Coefficient	SE	F	P
Caffeine intake per 100 mg
All Participants (n=5826)	-35.4	9.1	15.1	0.0005
Coffee Drinkers Only (n=3024)	-36.7	12.2	9.0	0.0054
No Coffee Intake Reported (n=2802)	-40.0	13.7	8.5	0.0067
Coffee Intake per 100 g (3.55 oz)
All Participants (n=5826)	15.0	4.2	12.6	0.0013
Coffee Drinkers Only (n=3024)	17.9	5.9	9.1	0.0053
No Coffee Intake Reported (n=2802)	–	–	–	–

Each regression model tested the linear association between the exposure variable, either caffeine or coffee intake, and telomere length, separated by coffee drinking status, after adjusting for the covariates. For the caffeine and telomere length associations, in the samples that included coffee drinkers, age, race, education, marital status, housing, BMI, physical activity (MET-minutes), smoking (pack-years), alcohol use, and coffee intake were controlled statistically. For the coffee and telomere length models, the same covariates were controlled, except adjustments were made for caffeine intake rather than coffee consumption. Interpretation of the first row of regression results should be as follows: After adjusting for the covariates, for each 100 mg of caffeine consumed per day by U.S. adults, telomere length was 35.4 base pairs shorter, on average