TABLE 2.

Incident hypertension and cumulative average intakes of flavonoids (total and subclasses in quintiles) in participants in the Nurses' Health Study (NHS) I, the NHS II, and the Health Professionals Follow-Up Study (HPFS)¹

Flavonoid	Quintile 1	Quintile 2	Quintile 3	Quintile 4	Quintile 5	P for trend
Flavonols
NHS II
No. of cases	2282	2214	2253	2313	2340	—
Person-years	160,275	167,691	168,830	166,985	159,058	—
Relative risk (95% CI)	1.0 (ref)	0.97 (0.91, 1.03)	0.97 (0.92, 1.04)	0.98 (0.92, 1.05)	1.00 (0.94, 1.07)	0.58
NHS I
No. of cases	3560	3714	3623	3514	3205	—
Person-years	103,645	105,671	103,580	101,502	96,684	—
Relative risk (95% CI)	1.0 (ref)	1.02 (0.97, 1.07)	1.01 (0.96, 1.06)	1.00 (0.95, 1.05)	0.96 (0.91, 1.01)	0.02
HPFS
No. of cases	1087	1170	1134	1141	1104	—
Person-years	42,553	44,709	43,682	42,792	39,026	—
Relative risk (95% CI)	1.0 (ref)	1.02 (0.94, 1.12)	1.01 (0.93, 1.11)	1.01 (0.92, 1.11)	1.07 (0.97, 1.18)	0.17
Pooled relative risk (95% CI)	1.0 (ref)	1.00 (0.97, 1.04)	1.00 (0.96, 1.03)	1.00 (0.96, 1.03)	1.00 (0.95, 1.01)	0.99
Flavones
NHS II
No. of cases	2360	2396	2228	2301	2117	—
Person-years	155,081	165,536	166,431	169,171	166,619	—
Relative risk (95% CI)	1.0 (ref)	0.98 (0.93, 1.04)	0.93 (0.87, 0.98)	0.97 (0.91, 1.04)	0.95 (0.88, 1.01)	0.17
NHS I
No. of cases	3625	3830	3606	3394	3161	—
Person-years	104,945	108,204	103,930	100,494	93,509	—
Relative risk (95% CI)	1.0 (ref)	1.00 (0.96, 1.05)	0.98 (0.93, 1.02)	0.95 (0.90, 1.00)	0.97 (0.92, 1.02)	0.09
HPFS
No. of cases	1107	1222	1130	1085	1092	—
Person-years	42,932	43,795	43,113	42,509	40,414	—
Relative risk (95% CI)	1.0 (ref)	1.12 (1.03, 1.22)	1.05 (0.96, 1.15)	1.05 (0.96, 1.15)	1.09 (0.98, 1.20)	0.44
Pooled relative risk (95% CI)	1.0 (ref)	1.02 (0.96, 1.09)	0.98 (0.92, 1.04)	0.98 (0.93, 1.03)	0.99 (0.93, 1.06)	0.28
Flavonones
NHS II
No. of cases	2334	2347	2285	2267	2169	—
Person-years	156,829	166,072	166,546	167,819	165,573	—
Relative risk (95% CI)	1.0 (ref)	0.97 (0.92, 1.03)	0.96 (0.91, 1.02)	0.98 (0.92, 1.04)	0.98 (0.92, 1.05)	0.92
NHS I
No. of cases	3497	3892	3679	3424	3124	—
Person-years	103,246	108,915	104,344	101,934	92,642	—
Relative risk (95% CI)	1.0 (ref)	1.04 (0.99, 1.09)	1.01 (0.97, 1.06)	0.97 (0.92, 1.02)	0.99 (0.94, 1.05)	0.14
HPFS
No. of cases	1161	1215	1168	1084	1008	—
Person-years	43,591	45,209	43,482	41,617	38,864	—
Relative risk (95% CI)	1.0 (ref)	1.05 (0.96, 1.14)	1.04 (0.92, 1.13)	1.05 (0.95, 1.15)	1.04 (0.94, 1.14)	0.63
Pooled relative risk (95% CI)	1.0 (ref)	1.02 (0.97, 1.07)	1.00 (0.96, 1.04)	0.99 (0.95, 1.02)	0.99 (0.96, 1.03)	0.39
Anthocyanins
NHS II
No. of cases	2379	2344	2301	2276	2102	—
Person-years	150,085	163,823	168,435	170,786	169,711	—
Relative risk (95% CI)	1.0 (ref)	0.94 (0.88, 0.99)	0.93 (0.87, 0.98)	0.91 (0.86, 0.97)	0.87 (0.81, 0.92)*	<0.0001
NHS I
No. of cases	3531	3569	3640	3616	3260	—
Person-years	100,201	102,378	103,767	104,063	100,673	—
Relative risk (95% CI)	1.0 (ref)	0.96 (0.91, 1.00)	0.97 (0.92, 1.02)	0.98 (0.93, 1.03)	0.93 (0.88, 0.98)*	0.02
HPFS
No. of cases	1137	1168	1140	1112	1079	—
Person-years	41,162	42,906	43,290	43,756	41,648	—
Relative risk (95% CI)	1.0 (ref)	0.99 (0.91, 1.08)	0.97 (0.89, 1.06)	0.98 (0.89, 1.07)	0.99 (0.90, 1.09)	0.82
Pooled relative risk (95% CI)	1.0 (ref)	0.96 (0.93, 0.99)	0.96 (0.92, 0.99)	0.95 (0.91, 1.01)	0.92 (0.86, 0.98)*	0.03
Flavan-3-ols
NHS II
No. of cases	2332	2134	2170	2311	2455	—
Person-years	159,269	166,255	170,197	165,959	161,159	—
Relative risk (95% CI)	1.0 (ref)	0.97 (0.91, 1.03)	0.96 (0.90, 1.02)	1.00 (0.94, 1.06)	1.03 (0.97, 1.09)	0.08
NHS I
No. of cases	3406	3533	3562	3597	3518	—
Person-years	98,181	103,210	103,130	102,945	103,615	—
Relative risk (95% CI)	1.0 (ref)	1.00 (0.95, 1.05)	1.01 (0.96, 1.06)	1.01 (0.96, 1.06)	0.98 (0.93, 1.03)	0.31
HPFS
No. of cases	1031	1104	1220	1141	1140	—
Person-years	40,501	43,027	44,372	43,659	41,204	—
Relative risk (95% CI)	1.0 (ref)	1.06 (0.97, 1.16)	1.14 (1.04, 1.24)	1.07 (0.98, 1.18)	1.12 (1.02, 1.22)	0.10
Pooled relative risk (95% CI)	1.0 (ref)	1.00 (0.96, 1.04)	1.03 (0.95, 1.12)	1.01 (0.98, 1.05)	1.03 (0.97, 1.11)	0.40
Polymers
NHS II
No. of cases	2331	2155	2234	2253	2429	—
Person-years	159,191	166,861	168,412	166,666	161,709	—
Relative risk (95% CI)	1.0 (ref)	0.93 (0.88, 0.99)	0.96 (0.91, 1.02)	0.96 (0.91, 1.02)	1.00 (0.94, 1.06)	0.34
NHS I
No. of cases	3456	3576	3551	3469	3564	—
Person-years	97,859	103,301	103,129	102,945	103,848	—
Relative risk (95% CI)	1.0 (ref)	0.98 (0.94, 1.03)	0.98 (0.93, 1.03)	0.96 (0.91, 1.01)	0.97 (0.93, 1.02)	0.56
HPFS
No. of cases	1125	1127	1153	1091	1140	—
Person-years	40,257	44,229	44,312	43,379	40,586	—
Relative risk (95% CI)	1.0 (ref)	0.98 (0.90,1.07)	1.04 (0.95,1.13)	0.99 (0.90,1.08)	1.08 (0.99,1.18)	0.04
Pooled relative risk (95% CI)	1.0 (ref)	0.96 (0.93, 1.00)	0.98 (0.95, 1.02)	0.96 (0.93, 1.00)	1.01 (0.95, 1.06)	0.36
Total flavonoids
NHS II
No. of cases	2330	2192	2253	2216	2411	—
Person-years	159,191	166,861	168,412	166,666	161,709	—
Relative risk (95% CI)	1.0 (ref)	0.95 (0.90, 1.01)	0.99 (0.93, 1.05)	0.96 (0.90, 1.02)	1.01 (0.95, 1.07)	0.41
NHS I
No. of cases	3615	3574	3468	3433	3526	—
Person-years	102,510	103,094	101,273	101,300	102,905	—
Relative risk (95% CI)	1.0 (ref)	0.96 (0.91, 1.00)	0.94 (0.89, 0.98)	0.92 (0.88, 0.97)	0.94 (0.90, 0.99)*	0.40
HPFS
No. of cases	1166	1124	1124	1094	1128	—
Person-years	41,618	44,231	44,329	42,267	40,318	—
Relative risk (95% CI)	1.0 (ref)	0.96 (0.88, 1.05)	0.99 (0.91, 1.08)	0.99 (0.91, 1.09)	1.06 (0.97, 1.16)	0.04
Pooled relative risk (95% CI)	1.0 (ref)	0.96 (0.93, 0.99)	0.97 (0.93, 1.00)	0.95 (0.91, 0.98)	1.00 (0.93, 1.07)	0.46

¹ref, reference. Multivariate model included age and smoking, BMI, physical activity, alcohol consumption, family history of hypertension, aspirin use, multivitamin use, and intakes of sodium, magnesium, potassium, fiber, whole grain, folate, and caffeine. *Quintile 5 compared with quintile 1, P < 0.001.