TABLE 4.
Associations between tea consumption and cognitive function tests in the UK Biobank
Cups/day | N | Score6 | Model 11 | Model 22 | Model 33 | |||
---|---|---|---|---|---|---|---|---|
β (95% CI) | P | β (95% CI) | P | β (95% CI) | P | |||
Fluid Intelligence4 | ||||||||
0 | 21,274 | 6.17 ± 2.14 | Reference | Reference | Reference | |||
<1 | 4355 | 6.79 ± 2.13 | 0.61 (0.54, 0.68) | <0.0001 | 0.25 (0.19,0.31) | <0.0001 | 0.24 (0.18, 0.30) | <0.0001 |
1 | 11,718 | 6.36 ± 2.13 | 0.19 (0.14, 0.23) | <0.0001 | −0.04 (−0.09, −0.0007) | 0.05 | −0.05 (−0.09, −0.003) | 0.04 |
2–3 | 41,643 | 6.23 ± 2.10 | 0.08 (0.04, 0.11) | <0.0001 | −0.10 (−0.14, −0.07) | <0.0001 | −0.11 (−0.14, −0.08) | <0.0001 |
4–5 | 38,111 | 6.06 ± 2.10 | −0.08 (−0.12, −0.05) | <0.0001 | −0.16 (−0.19, −0.13) | <0.0001 | −0.17 (−0.20, −0.14) | <0.0001 |
6–7 | 18,040 | 5.99 ± 2.07 | −0.15 (−0.19, −0.11) | <0.0001 | −0.15 (−0.19, −0.11) | <0.0001 | −0.16 (−0.20, −0.12) | <0.0001 |
≥8 | 10,822 | 5.80 ± 2.10 | −0.37 (−0.41, −0.32) | <0.0001 | −0.23 (−0.28, −0.19) | <0.0001 | −0.24 (−0.29, −0.20) | <0.0001 |
Cups/day, linear trend | −0.05 (−0.06, −0.05) | <0.0001 | −0.03 (−0.03, −0.02) | <0.0001 | −0.03 (−0.03, −0.03) | <0.0001 | ||
Reaction Time5 | ||||||||
0 | 65,281 | 547 ± 105 | Reference | Reference | Reference | |||
<1 | 13,581 | 543 ± 103 | −3.20 (−5.08, −1.32) | 0.0008 | 0.61 (−1.25, 2.47) | 0.52 | 0.48 (−1.38, 2.35) | 0.61 |
1 | 36,123 | 546 ± 104 | −1.05 (−2.35, 0.25) | 0.11 | 2.36 (1.07, 3.66) | 0.0004 | 2.24 (0.93, 3.54) | 0.0008 |
2–3 | 127,074 | 553 ± 107 | 1.07 (0.11, 2.03) | 0.03 | 4.19 (3.23, 5.15) | <0.0001 | 4.33 (3.34, 5.32) | <0.0001 |
4–5 | 114,519 | 557 ± 108 | 3.14 (2.16, 4.12) | <0.0001 | 5.04 (4.06, 6.02) | <0.0001 | 5.62 (4.60, 6.64) | <0.0001 |
6–7 | 53,608 | 559 ± 108 | 4.99 (3.83, 6.15) | <0.0001 | 5.83 (4.67, 6.99) | <0.0001 | 6.70 (5.50, 7.91) | <0.0001 |
≥8 | 31,856 | 558 ± 109 | 7.74 (6.38, 9.10) | <0.0001 | 5.48 (4.12, 6.84) | <0.0001 | 6.50 (5.10, 7.90) | <0.0001 |
Cups/day, linear trend | 0.95 (0.83, 1.06) | <0.0001 | 0.61 (0.50, 0.73) | <0.0001 | 0.72 (0.61, 0.84) | <0.0001 | ||
Pairs Matching5 | ||||||||
0 | 64,591 | 1.41 ± 0.62 | Reference | Reference | Reference | |||
<1 | 13,436 | 1.40 ± 0.63 | −0.015 (−0.026, −0.003) | 0.01 | 0.004 (−0.007, 0.016) | 0.47 | 0.002 (−0.009, 0.013) | 0.70 |
1 | 35,783 | 1.44 ± 0.63 | 0.019 (0.011, 0.027) | <0.0001 | 0.030 (0.022, 0.038) | <0.0001 | 0.027 (0.019, 0.035) | <0.0001 |
2–3 | 125,622 | 1.47 ± 0.62 | 0.036 (0.030, 0.042) | <0.0001 | 0.044 (0.038, 0.050) | <0.0001 | 0.042 (0.036, 0.0498) | <0.0001 |
4–5 | 113,091 | 1.48 ± 0.62 | 0.042 (0.036, 0.048) | <0.0001 | 0.046 (0.040, 0.052) | <0.0001 | 0.046 (0.040, 0.053) | <0.0001 |
6–7 | 52,892 | 1.48 ± 0.62 | 0.045 (0.038, 0.052) | <0.0001 | 0.046 (0.039, 0.053) | <0.0001 | 0.048 (0.040, 0.055) | <0.0001 |
≥8 | 31,407 | 1.48 ± 0.63 | 0.052 (0.043, 0.060) | <0.0001 | 0.046 (0.038, 0.054) | <0.0001 | 0.048 (0.040, 0.057) | <0.0001 |
Cups/day, linear trend | 0.006 (0.005, 0.006) | <0.0001 | 0.004 (0.004, 0.005) | <0.0001 | 0.005 (0.004, 0.005) | <0.0001 | ||
Symbol Digit Substitution4 | ||||||||
0 | 16,104 | 20.3 ± 5.2 | Reference | Reference | Reference | |||
<1 | 4287 | 20.4 ± 5.1 | 0.14 (−0.01, 0.30) | 0.08 | −0.10 (−0.25, 0.05) | 0.20 | −0.09 (−0.24, 0.06) | 0.24 |
1 | 9859 | 20.2 ± 5.1 | 0.07 (−0.04, 0.19) | 0.22 | −0.12 (−0.23, −0.004) | 0.04 | −0.11 (−0.23, 0.002) | 0.05 |
2–3 | 33,407 | 19.8 ± 5.1 | −0.14 (−0.22, −0.05) | 0.002 | −0.30 (−0.39, −0.22) | <0.0001 | −0.31 (−0.40, −0.22) | <0.0001 |
4–5 | 27,793 | 19.5 ± 5.2 | −0.37 (−0.46, −0.28) | <0.0001 | −0.45 (−0.54, −0.37) | <0.0001 | −0.48 (−0.57, −0.39) | <0.0001 |
6–7 | 12,368 | 19.3 ± 5.2 | −0.54 (−0.65, −0.43) | <0.0001 | −0.54 (−0.64, −0.43) | <0.0001 | −0.58 (−0.69, −0.47) | <0.0001 |
≥8 | 6822 | 19.4 ± 5.3 | −0.72 (−0.86, −0.59) | <0.0001 | −0.61 (−0.74, −0.48) | <0.0001 | −0.66 (−0.79, −0.53) | <0.0001 |
Cups/day, linear trend | −0.09 (−0.10, −0.08) | <0.0001 | −0.07 (−0.08, −0.06) | <0.0001 | −0.08 (−0.09, −0.07) | <0.0001 | ||
Trail A5 | ||||||||
0 | 14,356 | 3.58 ± 0.32 | Reference | Reference | Reference | |||
<1 | 3828 | 3.57 ± 0.31 | −0.009 (−0.020, 0.002) | 0.11 | 0.002 (−0.008, 0.013) | 0.66 | 0.003 (−0.008, 0.013) | 0.63 |
1 | 8722 | 3.59 ± 0.32 | 0.004 (−0.004, 0.012) | 0.34 | 0.013 (0.004, 0.021) | 0.002 | 0.013 (0.005, 0.021) | 0.001 |
2–3 | 29,394 | 3.61 ± 0.32 | 0.014 (0.008, 0.020) | <0.0001 | 0.020 (0.014, 0.027) | <0.0001 | 0.021 (0.015, 0.028) | <0.0001 |
4–5 | 24,291 | 3.62 ± 0.33 | 0.027 (0.021, 0.033) | <0.0001 | 0.029 (0.022, 0.035) | <0.0001 | 0.030 (0.024, 0.037) | <0.0001 |
6–7 | 10,788 | 3.63 ± 0.33 | 0.036 (0.028, 0.043) | <0.0001 | 0.033 (0.025, 0.040) | <0.0001 | 0.035 (0.027, 0.043) | <0.0001 |
≥8 | 5992 | 3.62 ± 0.33 | 0.037 (0.028, 0.046) | <0.0001 | 0.030 (0.020, 0.039) | <0.0001 | 0.032 (0.022, 0.041) | <0.0001 |
Cups/day, linear trend | 0.005 (0.004, 0.006) | <0.0001 | 0.004 (0.003, 0.005) | <0.0001 | 0.004 (0.003, 0.005) | <0.0001 | ||
Trail B5 | ||||||||
0 | 14,356 | 4.10 ± 0.33 | Reference | Reference | Reference | |||
<1 | 3828 | 4.08 ± 0.32 | −0.024 (−0.035, −0.013) | <0.0001 | −0.004 (−0.015, 0.007) | 0.46 | −0.004 (−0.014, 0.007) | 0.50 |
1 | 8722 | 4.11 ± 0.33 | 0.004 (−0.004, 0.013) | 0.29 | 0.020 (0.012, 0.028) | <0.0001 | 0.020 (0.012, 0.028) | <0.0001 |
2–3 | 29,393 | 4.13 ± 0.33 | 0.011 (0.005, 0.018) | 0.0003 | 0.025 (0.019, 0.031) | <0.0001 | 0.025 (0.019, 0.031) | <0.0001 |
4–5 | 24,290 | 4.15 ± 0.34 | 0.027 (0.021, 0.033) | <0.0001 | 0.034 (0.028, 0.040) | <0.0001 | 0.035 (0.029, 0.042) | <0.0001 |
6–7 | 10,788 | 4.16 ± 0.34 | 0.040 (0.032, 0.047) | <0.0001 | 0.039 (0.031, 0.047) | <0.0001 | 0.041 (0.034, 0.049) | <0.0001 |
≥8 | 5992 | 4.15 ± 0.35 | 0.045 (0.036, 0.055) | <0.0001 | 0.036 (0.027, 0.045) | <0.0001 | 0.039 (0.030, 0.048) | <0.0001 |
Cups/day, linear trend | 0.006 (0.005, 0.007) | <0.0001 | 0.005 (0.004, 0.005) | <0.0001 | 0.005 (0.004, 0.006) | <0.0001 | ||
Prospective Memory Test4 | ||||||||
N | % correct | OR (95% CI) | P | OR (95% CI) | P | OR (95% CI) | P | |
0 | 21,672 | 81.0 | Reference | Reference | Reference | |||
<1 | 4418 | 85.5 | 1.39 (1.27, 1.52) | <0.0001 | 1.16 (1.05, 1.27) | 0.002 | 1.15 (1.04, 1.27) | 0.003 |
1 | 11,931 | 81.6 | 1.05 (0.99, 1.11) | 0.10 | 0.92 (0.87, 0.98) | 0.01 | 0.93 (0.87, 0.98) | 0.01 |
2–3 | 42,405 | 79.5 | 0.96 (0.92, 1.00) | 0.07 | 0.86 (0.82, 0.90) | <0.0001 | 0.86 (0.82, 0.90) | <0.0001 |
4–5 | 38,951 | 78.6 | 0.92 (0.88, 0.96) | <0.0001 | 0.86 (0.82, 0.90) | <0.0001 | 0.85 (0.81, 0.89) | <0.0001 |
6–7 | 18,453 | 78.1 | 0.89 (0.85, 0.94) | <0.0001 | 0.86 (0.82, 0.91) | <0.0001 | 0.84 (0.80, 0.89) | <0.0001 |
≥8 | 11,155 | 76.6 | 0.79 (0.75, 0.84) | <0.0001 | 0.83 (0.79, 0.88) | <0.0001 | 0.82 (0.77, 0.87) | <0.0001 |
Cups/day, linear trend | 0.97 (0.97, 0.98) | <0.0001 | 0.98 (0.98, 0.99) | <0.0001 | 0.98 (0.97, 0.98) | <0.0001 |
Model 1: adjusted for age and sex.
Model 2: adjusted for age, sex, smoking, Townsend deprivation index, education, income, employment status, homeownership, self-reported health, waist-to-hip ratio, physical activity, fasting time and intakes of alcohol, water, fish, red meat, and fruit and vegetables.
Model 3: model 2 adjusted for regular coffee consumption.
Positive β-coefficients for FI (difference in 13-point score) and SDS (difference in number of correct substitutions) and OR >1 for PM (correct on first attempt) correspond to higher performance compared with nondrinkers (0 cups/d).
Negative β-coefficients for Pairs [difference in (log-transformed) number of errors], RT (difference in time, seconds, to respond), Trails A and Trails B [difference in (log transformed) time to complete] correspond to higher performance compared with nondrinkers (0 cups/d).
Data are raw mean ± SD scores of each cognitive function test stratified by tea consumption.
FI, fluid intelligence; Pairs, Pairs Matching; PM, prospective memory; RT, reaction time; SDS, symbol digit substitution.