TABLE 1.
Baseline characteristics of UK Biobank participants according to level of regular coffee consumption1
| Characteristic | Regular coffee consumption, cups/day | ||||||
|---|---|---|---|---|---|---|---|
| None | <1 | 1 | 2–3 | 4–5 | 6–7 | ≥8 | |
| N = 161,309 | N = 25,043 | N = 71,503 | N = 114,674 | N = 49,204 | N = 14,998 | N = 7370 | |
| Age, y | 56.5 ± 8.1 | 56.5 ± 7.9 | 57.4 ± 8.0 | 57.0 ± 8.0 | 56.3 ± 8.0 | 56.0 ± 8.0 | 54.4 ± 8.0 |
| Male, n (%) | 63,291 (39.2) | 11,694 (46.7) | 31,786 (44.5) | 55,482 (48.4) | 26,054 (53.0) | 8118 (54.1) | 4406 (59.8) |
| Current smoker, n (%) | 13,970 (8.7) | 2198 (8.8) | 5652 (7.9) | 11,355 (9.9) | 7520 (15.3) | 3505 (23.4) | 2697 (36.6) |
| BMI, kg/m2 | 27.4 ± 4.9 | 27.1 ± 4.7 | 27.0 ± 4.6 | 27.2 ± 4.6 | 27.9 ± 4.7 | 28.2 ± 5.0 | 28.2 ± 5.1 |
| Income, £<18,000, n (%) | 32,416 (20.1) | 4485 (17.9) | 13,792 (19.3) | 18,973 (16.6) | 8223 (16.7) | 3040 (20.3) | 1716 (23.3) |
| College or university degree, n (%) | 45,294 (28.1) | 8729 (34.9) | 24,310 (34.0) | 42,691 (37.2) | 16,699 (33.9) | 4229 (28.2) | 1898 (25.8) |
| Currently employed, n (%) | 92,215 (57.2) | 14,703 (58.7) | 38,631 (54.0) | 66,501 (58.0) | 31,043 (63.1) | 9589 (63.9) | 4850 (65.8) |
| Townsend deprivation score | −1.47 ± 2.99 | −1.48 ± 2.93 | −1.52 ± 2.94 | −1.57 ± 2.93 | −1.52 ± 2.95 | −1.22 ± 3.09 | −0.55 ± 3.37 |
| Homeowner, n (%) | 144,155 (89) | 22,696 (90.6) | 64,990 (90.9) | 104,634 (91.2) | 44,293 (90.0) | 13,045 (87.0) | 5913 (80.2) |
| Moderate to vigorous physical activity, minutes/week | 76 ± 98 | 74 ± 92 | 78 ± 93 | 77 ± 93 | 75 ± 97 | 75 ± 109 | 81 ± 123 |
| Hypertension, n (%) | 84,210 (52.2) | 13,378 (53.4) | 38,779 (54.2) | 61,448 (53.6) | 26,502 (53.9) | 8064 (53.8) | 3635 (49.3) |
| Diabetes, n (%) | 7643 (4.7) | 1138 (4.5) | 3119 (4.4) | 5063 (4.4) | 2545 (5.2) | 824 (5.5) | 452 (6.1) |
| Poor overall health rating, n (%) | 7116 (4.4) | 947 (3.8) | 2326 (3.3) | 3315 (2.9) | 1713 (3.5) | 703 (4.7) | 600 (8.2) |
| Alcohol, drinks/week | 0.99 ± 1.35 | 1.24 ± 1.49 | 1.25 ± 1.43 | 1.36 ± 1.43 | 1.39 ± 1.50 | 1.35 ± 1.64 | 1.32 ± 1.80 |
| Fish, servings/week | 0.32 ± 0.23 | 0.32 ± 0.22 | 0.33 ± 0.22 | 0.32 ± 0.22 | 0.31 ± 0.22 | 0.29 ± 0.22 | 0.29 ± 0.24 |
| Red meat, servings/week | 0.49 ± 0.31 | 0.51 ± 0.31 | 0.50 ± 0.30 | 0.52 ± 0.31 | 0.54 ± 0.32 | 0.56 ± 0.34 | 0.59 ± 0.38 |
| Fruit, servings/week | 3.06 ± 2.58 | 2.94 ± 2.36 | 3.13 ± 2.48 | 3.03 ± 2.43 | 2.80 ± 2.37 | 2.62 ± 2.41 | 2.53 ± 2.93 |
| Vegetable, servings/week | 0.81 ± 0.54 | 0.77 ± 0.50 | 0.81 ± 0.51 | 0.81 ± 0.52 | 0.79 ± 0.53 | 0.79 ± 0.58 | 0.78 ± 0.66 |
| Decaffeinated coffee consumer, n (%) | 67,642 (42) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Tea, cups/day | 4.0 ± 2.9 | 4.6 ± 2.5 | 3.9 ± 2.4 | 2.9 ± 2.3 | 2.1 ± 2.3 | 1.7 ± 2.6 | 2.0 ± 3.5 |
| Coffee-/tea-derived caffeine, mg/day | 161 ± 115 | 223 ± 100 | 231 ± 95 | 297 ± 93 | 410 ± 95 | 535 ± 109 | 790 ± 213 |
| Recent caffeine drinking, n (%) | 2602 (1.8) | 357 (1.6) | 1267 (1.9) | 2321 (2.2) | 1205 (2.7) | 461 (3.4) | 274 (4.1) |
| CMSG2 | 1.69 ± 0.92 | 1.64 ± 0.92 | 1.67 ± 0.92 | 1.72 ± 0.92 | 1.80 ± 0.92 | 1.86 ± 0.93 | 1.90 ± 0.94 |
| APOE ε4 carriers, n (%) | 37,084 (28.5) | 5893 (29.0) | 16,497 (28.3) | 26,776 (28.5) | 11,392 (28.5) | 3502 (28.7) | 1649 (27.7) |
1Data drawn from 2006–2010 for self-described white participants with information on coffee and tea intake and who completed ≥1 of the cognitive function tests. Values are mean ± SD or n (%). All characteristic values are significantly different across coffee categories (P < 0.0001) with the exception of APOE (P = 0.47).
2CMSG: caffeine metabolism score; derived by summing the number of single-nucleotide polymorphism alleles multiplied by their β-coefficients and recalibrated such that it ranged from 0 to 4, with higher scores predicting faster caffeine metabolism.