Table 3.
Effects of diet on CYP1A2 activity: the ratio between responses to basal and vegetable-supplemented diets
| Basal CYP1A2 Activitya | 1C/Basal Fold Changeb | 2C/Basal Fold Changeb | 1C+A/Basal Fold Changeb | |
|---|---|---|---|---|
| Total (n = 73) | 2.91 ± 0.09 | 1.14 ± 0.04c | 1.27 ± 0.04c | 0.99 ± 0.03 |
| Men (n = 35) | 3.06 ± 0.13 | 1.09 ± 0.05 | 1.27 ± 0.06c | 0.95 ± 0.04 |
| Women (n = 38) | 2.77 ± 0.12 | 1.19 ± 0.05c | 1.27 ± 0.06c | 1.04 ± 0.05 |
| CYP1A2*1F | ||||
| A/A (n = 31) | 3.12 ± 0.13 | 1.09 ± 0.05 | 1.26 ± 0.06c | 0.95 ± 0.04 |
| A/C (n = 30) | 2.87 ± 0.13 | 1.13 ± 0.05c | 1.31 ± 0.06c | 1.03 ± 0.05 |
| C/C (n = 12) | 2.76 ± 0.19 | 1.20 ± 0.08c | 1.23 ± 0.09c | 1.00 ± 0.07 |
| GSTM1/GSTT1 | ||||
| M1+/T1+ (n = 26) | 2.91 ± 0.13 | 1.10 ± 0.05c | 1.25 ± 0.05c | 1.02 ± 0.04 |
| M1-null/T1+ (n = 31) | 3.07 ± 0.12 | 1.12 ± 0.04c | 1.24 ± 0.05c | 0.95 ± 0.04 |
| M1-null/T1-null (n = 14) | 2.95 ± 0.19 | 1.07 ± 0.07 | 1.35 ± 0.10c | 0.90 ± 0.07 |
a
Least squares means ± SE of caffeine metabolite ratio (measure of CYP1A2 activity).
b
Least squares means ± SE of fold change in caffeine metabolite ratio; analyses were performed on log-transformed data and adjusted for baseline CYP1A2 activity, CYP1A2*1F genotype, GSTM1 genotype, GSTT1 genotype, sex, period, and order; the results presented are after back-transformation.
c
Significant comparison between vegetable and basal diets (P < 0.05).