TABLE 2.
HRs (95% CIs) of type 2 diabetes risk according to flavonoid intake in the NHS (1984–2008), NHS II (1991–2007), and HPFS (1986–2006)1
| Frequency of consumption |
||||||
| Q1 | Q2 | Q3 | Q4 | Q5 | P-trend | |
| Flavonols | ||||||
| NHS | ||||||
| Median value (mg/d) | 6.1 | 9.2 | 12.3 | 16.4 | 27.0 | |
| Cases/person-years | 1676/289,182 | 1389/305,484 | 1351/308,834 | 1242/313,506 | 1220/310,591 | |
| Model 12 | 1.00 | 0.85 (0.79, 0.91) | 0.85 (0.79, 0.91) | 0.78 (0.73, 0.84) | 0.77 (0.71, 0.83) | <0.001 |
| Model 23 | 1.00 | 0.93 (0.87, 1.00) | 0.96 (0.89, 1.03) | 0.91 (0.84, 0.98) | 0.84 (0.78, 0.91) | <0.001 |
| NHS II | ||||||
| Median value (mg/d) | 7.5 | 11.4 | 15.1 | 20.6 | 33.6 | |
| Cases/person-years | 785/276,085 | 510/279,559 | 548/281,107 | 552/280,187 | 689/275,874 | |
| Model 12 | 1.00 | 0.75 (0.67, 0.84) | 0.82 (0.74, 0.92) | 0.83 (0.74, 0.92) | 0.93 (0.84, 1.03) | 0.74 |
| Model 23 | 1.00 | 0.85 (0.76, 0.95) | 0.95 (0.85, 1.07) | 0.94 (0.84, 1.05) | 0.99 (0.89, 1.10) | 0.46 |
| HPFS | ||||||
| Median value (mg/d) | 6.6 | 10.0 | 13.1 | 17.2 | 26.8 | |
| Cases/person-years | 650/144,126 | 565/144,837 | 501/145,141 | 437/145,473 | 496/145,598 | |
| Model 12 | 1.00 | 0.90 (0.80, 1.01) | 0.82 (0.73, 0.92) | 0.73 (0.64, 0.82) | 0.79 (0.71, 0.89) | <0.001 |
| Model 23 | 1.00 | 0.98 (0.87, 1.10) | 0.92 (0.82, 1.04) | 0.83 (0.73, 0.94) | 0.88 (0.78, 1.00) | 0.02 |
| Pooled results4 | ||||||
| Random-effects model | 1.00 | 0.92 (0.86, 0.99) | 0.95 (0.90, 1.00) | 0.90 (0.85, 0.95) | 0.90 (0.81, 0.99) | 0.18 |
| P-heterogeneity | — | 0.20 | 0.85 | 0.35 | 0.06 | 0.001 |
| Flavones | ||||||
| NHS | ||||||
| Median value (mg/d) | 0.7 | 1.3 | 1.8 | 2.4 | 3.4 | |
| Cases/person-years | 1503/298,859 | 1384/310,739 | 1413/309,181 | 1343/308,847 | 1235/299,971 | |
| Model 12 | 1.00 | 0.89 (0.83, 0.96) | 0.92 (0.85, 0.99) | 0.92 (0.85, 0.99) | 0.90 (0.84, 0.97) | 0.05 |
| Model 23 | 1.00 | 0.96 (0.89, 1.04) | 1.03 (0.95, 1.11) | 1.05 (0.97, 1.13) | 1.07 (0.99, 1.16) | 0.02 |
| NHS II | ||||||
| Median value (mg/d) | 0.6 | 1.0 | 1.4 | 1.9 | 2.9 | |
| Cases/person-years | 806/273,758 | 650/278,077 | 607/278,825 | 541/281,259 | 480/280,892 | |
| Model 12 | 1.00 | 0.91 (0.82, 1.01) | 0.92 (0.83, 1.02) | 0.85 (0.76, 0.95) | 0.86 (0.77, 0.97) | 0.006 |
| Model 23 | 1.00 | 1.00 (0.90, 1.11) | 1.07 (0.95, 1.19) | 1.00 (0.89, 1.12) | 1.02 (0.91, 1.16) | 0.75 |
| HPFS | ||||||
| Median value (mg/d) | 0.8 | 1.6 | 2.2 | 3.0 | 4.3 | |
| Cases/person-years | 553/144,874 | 582/145,336 | 478/144,999 | 533/145,027 | 503/144,941 | |
| Model 12 | 1.00 | 1.05 (0.94, 1.18) | 0.88 (0.78, 0.99) | 1.02 (0.91, 1.15) | 0.94 (0.83, 1.06) | 0.28 |
| Model 23 | 1.00 | 1.12 (1.00, 1.26) | 0.96 (0.84, 1.08) | 1.14 (1.01, 1.29) | 1.07 (0.94, 1.22) | 0.37 |
| Pooled results4 | ||||||
| Random-effects model | 1.00 | 1.02 (0.93, 1.11) | 1.02 (0.97, 1.08) | 1.05 (0.99, 1.12) | 1.06 (1.00, 1.12) | 0.02 |
| P-heterogeneity | — | 0.10 | 0.44 | 0.32 | 0.83 | 0.61 |
| Flavanones | ||||||
| NHS | ||||||
| Median value (mg/d) | 7.9 | 21.7 | 37.1 | 54.0 | 82.4 | |
| Cases/person-years | 1486/299,878 | 1404/312,037 | 1382/311,909 | 1357/306,655 | 1249/297,119 | |
| Model 12 | 1.00 | 0.89 (0.82, 0.95) | 0.89 (0.83, 0.96) | 0.93 (0.87, 1.00) | 0.91 (0.84, 0.98) | 0.13 |
| Model 23 | 1.00 | 0.96 (0.89, 1.03) | 0.98 (0.91, 1.06) | 1.05 (0.97, 1.13) | 1.05 (0.97, 1.13) | 0.05 |
| NHS II | ||||||
| Median value (mg/d) | 6.2 | 14.7 | 25.0 | 40.0 | 70.6 | |
| Cases/person-years | 769/273,887 | 619/278,715 | 592/280,250 | 543/280,636 | 561/279,323 | |
| Model 12 | 1.00 | 0.88 (0.80, 0.98) | 0.89 (0.80, 0.99) | 0.84 (0.75, 0.94) | 0.96 (0.86, 1.07) | 0.63 |
| Model 23 | 1.00 | 0.95 (0.85, 1.06) | 0.98 (0.88, 1.09) | 0.94 (0.84, 1.05) | 1.08 (0.97, 1.22) | 0.13 |
| HPFS | ||||||
| Median value (mg/d) | 8.7 | 25.6 | 44.6 | 64.6 | 100.1 | |
| Cases/person-years | 559/144,599 | 527/145,249 | 535/145,112 | 514/145,067 | 514/145,150 | |
| Model 12 | 1.00 | 0.97 (0.86, 1.10) | 1.00 (0.89, 1.13) | 0.99 (0.88, 1.12) | 0.99 (0.88, 1.12) | 0.96 |
| Model 23 | 1.00 | 1.03 (0.92, 1.17) | 1.06 (0.94, 1.20) | 1.08 (0.95, 1.22) | 1.09 (0.96, 1.24) | 0.14 |
| Pooled results4 | ||||||
| Random-effects model | 1.00 | 0.97 (0.92, 1.02) | 1.00 (0.94, 1.06) | 1.02 (0.95, 1.10) | 1.06 (1.00, 1.13) | 0.004 |
| P-heterogeneity | — | 0.52 | 0.52 | 0.19 | 0.79 | 0.94 |
| Flavan-3-ols | ||||||
| NHS | ||||||
| Median value (mg/d) | 8.4 | 15.6 | 27.0 | 54.6 | 135.1 | |
| Cases/person-years | 1614/295,137 | 1331/306,390 | 1261/312,298 | 1363/306,983 | 1309/306,789 | |
| Model 12 | 1.00 | 0.85 (0.79, 0.92) | 0.82 (0.76, 0.88) | 0.89 (0.83, 0.96) | 0.85 (0.79, 0.91) | 0.03 |
| Model 23 | 1.00 | 0.94 (0.87, 1.01) | 0.91 (0.85, 0.98) | 0.95 (0.88, 1.02) | 0.87 (0.81, 0.94) | 0.002 |
| NHS II | ||||||
| Median value (mg/d) | 9.0 | 16.5 | 27.7 | 56.2 | 148.4 | |
| Cases/person-years | 784/274,916 | 510/279,651 | 510/281,582 | 575/279,240 | 705/277,424 | |
| Model 12 | 1.00 | 0.78 (0.70, 0.87) | 0.84 (0.75, 0.94) | 0.86 (0.78, 0.96) | 0.98 (0.88, 1.08) | 0.06 |
| Model 23 | 1.00 | 0.91 (0.81, 1.02) | 0.98 (0.87, 1.10) | 0.96 (0.86, 1.07) | 1.01 (0.91, 1.12) | 0.40 |
| HPFS | ||||||
| Median value (mg/d) | 9.0 | 16.7 | 25.4 | 43.9 | 103.9 | |
| Cases/person-years | 653/144,321 | 527/145,054 | 457/145,424 | 487/145,311 | 525/145,066 | |
| Model 12 | 1.00 | 0.84 (0.75, 0.94) | 0.76 (0.68, 0.86) | 0.82 (0.73, 0.93) | 0.85 (0.76, 0.96) | 0.25 |
| Model 23 | 1.00 | 0.90 (0.80, 1.02) | 0.85 (0.75, 0.96) | 0.91 (0.80, 1.02) | 0.88 (0.78, 0.99) | 0.22 |
| Pooled results4 | ||||||
| Random-effects model | 1.00 | 0.92 (0.87, 0.98) | 0.91 (0.85, 0.98) | 0.94 (0.89, 0.99) | 0.91 (0.84, 1.00) | 0.32 |
| P-heterogeneity | — | 0.80 | 0.27 | 0.78 | 0.07 | 0.03 |
| Anthocyanins | ||||||
| NHS | ||||||
| Median value (mg/d) | 2.2 | 4.7 | 8.1 | 13.1 | 22.3 | |
| Cases/person-years | 1688/286,253 | 1513/303,189 | 1293/314,489 | 1251/314,333 | 1133/309,332 | |
| Model 12 | 1.00 | 0.87 (0.81, 0.93) | 0.75 (0.70, 0.81) | 0.75 (0.70, 0.80) | 0.69 (0.64, 0.74) | <0.001 |
| Model 23 | 1.00 | 0.93 (0.86, 0.99) | 0.84 (0.78, 0.91) | 0.85 (0.79, 0.92) | 0.83 (0.77, 0.90) | <0.001 |
| NHS II | ||||||
| Median value (mg/d) | 2.0 | 4.5 | 8.0 | 13.7 | 24.3 | |
| Cases/person-years | 898/270,677 | 702/277,111 | 513/281,465 | 515/281,334 | 456/282,225 | |
| Model 12 | 1.00 | 0.87 (0.79, 0.96) | 0.72 (0.64, 0.80) | 0.74 (0.66, 0.82) | 0.68 (0.61, 0.76) | <0.001 |
| Model 23 | 1.00 | 0.98 (0.88, 1.08) | 0.84 (0.75, 0.94) | 0.88 (0.79, 0.99) | 0.83 (0.73, 0.94) | 0.002 |
| HPFS | ||||||
| Median value (mg/d) | 2.3 | 4.9 | 8.3 | 14.0 | 24.2 | |
| Cases/person-years | 621/144,223 | 541/144,956 | 519/145,403 | 508/145,413 | 460/145,183 | |
| Model 12 | 1.00 | 0.90 (0.80, 1.01) | 0.88 (0.78, 0.99) | 0.87 (0.77, 0.98) | 0.80 (0.70, 0.90) | <0.001 |
| Model 23 | 1.00 | 0.95 (0.84, 1.06) | 0.96 (0.85, 1.08) | 0.95 (0.84, 1.07) | 0.93 (0.81, 1.05) | 0.34 |
| Pooled results4 | ||||||
| Random-effects model | 1.00 | 0.94 (0.89, 0.99) | 0.87 (0.80, 0.94) | 0.88 (0.83, 0.94) | 0.85 (0.80, 0.91) | <0.001 |
| P for heterogeneity | — | 0.69 | 0.15 | 0.33 | 0.34 | 0.20 |
| Total flavonoids | ||||||
| NHS | ||||||
| Median value (mg/d) | 105.2 | 174.8 | 249.2 | 369.1 | 718.1 | |
| Cases/person-years | 1580/295,862 | 1377/306,228 | 1309/311,654 | 1348/307,160 | 1264/306,694 | |
| Model 12 | 1.00 | 0.87 (0.81, 0.94) | 0.84 (0.78, 0.91) | 0.88 (0.82, 0.95) | 0.82 (0.76, 0.89) | <0.001 |
| Model 23 | 1.00 | 0.95 (0.88, 1.02) | 0.93 (0.86, 1.01) | 0.96 (0.89, 1.03) | 0.85 (0.79, 0.92) | <0.001 |
| NHS II | ||||||
| Median value (mg/d) | 112.1 | 182.5 | 256.1 | 378.4 | 770.3 | |
| Cases/person-years | 754/274,738 | 554/280,370 | 506/280,556 | 582/279,499 | 688/277,648 | |
| Model 12 | 1.00 | 0.85 (0.76, 0.95) | 0.82 (0.73, 0.92) | 0.92 (0.82, 1.02) | 0.98 (0.89, 1.09) | 0.20 |
| Model 23 | 1.00 | 0.94 (0.84, 1.05) | 0.92 (0.82, 1.03) | 1.00 (0.89, 1.12) | 0.99 (0.89, 1.11) | 0.56 |
| HPFS | ||||||
| Median value (mg/d) | 112.5 | 182.2 | 251.7 | 352.9 | 624.3 | |
| Cases/person-years | 600/144,345 | 540/145,059 | 505/145,303 | 501/145,241 | 503/145,228 | |
| Model 12 | 1.00 | 0.93 (0.83, 1.05) | 0.92 (0.82, 1.03) | 0.90 (0.80, 1.02) | 0.88 (0.79, 1.00) | 0.07 |
| Model 23 | 1.00 | 0.98 (0.87, 1.11) | 1.00 (0.89, 1.13) | 0.97 (0.86, 1.10) | 0.92 (0.81, 1.04) | 0.15 |
| Pooled results4 | ||||||
| Random-effects model | 1.00 | 0.95 (0.90, 1.01) | 0.94 (0.89, 1.00) | 0.97 (0.92, 1.03) | 0.92 (0.83, 1.01) | 0.21 |
| P-heterogeneity | — | 0.84 | 0.53 | 0.83 | 0.07 | 0.02 |
1
HPFS, Health Professionals Follow-Up Study; NHS, Nurses’ Health Study; Q, quintile.
2
Adjusted for age (continuous) and BMI category (in kg/m2; <23, 23.0–24.9, 25.0–26.9, 27.0–28.9, 29.0–30.9, 31.0–32.9, 33.0–34.9, 35.0–36.9, 37.0–38.9, 39.0–40.9, 41.0–42.9, 43.0–44.9, or ≥45.0).
3
Further adjusted for variables in model 1 plus smoking status [never smoker, past smoker, or current smoker (1–14, 15–24, or ≥25 cigarettes/d)], alcohol intake (0, 0.1–4.9, 5.0–9.9, 10.0–14.9, or ≥15 g/d in women; 0, 0.1–4.9, 5.0–29.9, or ≥30 g/d in men), multivitamin use (yes or no), physical activity (quintiles of hours of metabolic equivalent tasks per week), a family history of diabetes, postmenopausal status and hormone use (NHS and NHS II), oral contraceptive use (NHS II), ethnicity (white, African American, Hispanic, or Asian), total energy (kcal/d), and polyunsaturated:saturated fat ratio and intakes of red meat, fish, whole grains, coffee, high-calorie sodas (including punch), and trans fat (all in quintiles).
4
Data were pooled by using random-effects model of results from model 2.