TABLE 1.

Age-adjusted characteristics of women at the initial cognitive interview in the Nurses’ Health Study cognitive substudy by selected quintiles of total ferric-reducing antioxidant power (FRAP) scores (n = 16,010)¹

	Quintile 1	Quintile 3	Quintile 5	P2
n	3202	3202	3202
FRAP score (mmol/d)3	8.1 (7.0–8.9)	12.5 (12.0–13.0)	19.5 (17.8–22.6)
Age (y)4	74.3 ± 2.3	74.2 ± 2.3	74.2 ± 2.3	0.04
Education (%)5
RN degree	80	77	73
Bachelor's degree	15	17	19
Graduate degree	5	6	8	<0.0001
Alcohol intake (%)5
None	62	44	44
1–14 g/d	33	46	46
≥15 g/d	5	10	10	<0.0001
Antidepressant use (%)5	5	6	6	0.05
Smoking (%)
Never	55	45	41
Former	39	47	50
Current	6	8	10	<0.0001
Physical activity (MET-h)	13.5	16.7	18.2	<0.0001
BMI (%)5
<22 kg/m2	17	21	24
22–24 kg/m2	24	26	29
25–29 kg/m2	37	36	32
≥30 kg/m2	22	17	15	<0.0001
Vitamin E supplement use (%)5	32	47	76	<0.0001
Vitamin C supplement use (%)5
None	85	65	22
Seasonal	6	11	11
Regular	9	24	67	<0.0001
Multivitamin use (%)5	51	64	76	<0.0001
High blood pressure (%)5,6	59	55	53	<0.0001
Myocardial infarction (%)5,6	6	6	5	0.04
Type 2 diabetes (%)5,6	14	10	8	<0.0001

¹RN, registered nurse; MET-h, metabolic equivalent hour (ie, the amount of energy expended during 1 h of sitting). Total FRAP scores were averaged from 1980 until the initial cognitive interview.

²Derived from multinomial logistic regression models, with the ordinal variable for the total FRAP score (in quintiles) included as the response variable and predictors included as either categorical or continuous variables. All models included age as a continuous variable.

³Values are medians; interquartile ranges in parentheses.

⁴Values are means ± SDs.

⁵Percentages of nonmissing values.

⁶Refers to a history of the condition indicated.