Table 3.

Pooled RRs of prostate cancer and 95% CIs for intakes of tomato and lycopene and concentrations of serum lycopene

Moderate intake or concentration
High intake or concentration
No. studiesPooled RRRiQ test (P value)Pooled RRRiQ test (P value)
Raw tomato (all studies)90.94 (0.88–1.01)0.430.090.89 (0.80–1.00)0.500.05
Raw tomato (case-control)70.97 (0.89–1.05)0.380.160.98 (0.86–1.12)0.260.24
Raw tomato (cohort)20.88 (0.77–1.00)0.830.100.71 (0.57–0.87)0.010.34
Cooked tomato (all studies)61.07 (1.06–1.08)0.980.100.81 (0.71–0.92)0.000.90
Cooked tomato (case-control)51.07 (1.06–1.08)0.940.350.88 (0.71–1.11)0.000.96
Lycopene intake (all studies)100.99 (0.93–1.06)a0.010.730.89 (0.81–0.98)0.280.23
Lycopene intake (case-control)70.97 (0.86–1.09)0.010.580.98 (0.83–1.16)0.000.48
Lycopene intake (cohort)31.00 (0.92–1.08)b0.010.550.84 (0.75–0.95)0.670.14
Serum lycopene (all studies)70.85 (0.75–0.97)0.010.680.74 (0.59–0.92)0.000.44
Serum lycopene (case-control)20.74 (0.53–1.04)0.630.150.55 (0.32–0.94)0.790.11
Serum lycopene (cohort)50.87 (0.76–1.00)0.010.890.78 (0.61–1.00)0.000.76
  • Note: Moderate intake corresponds to the 2nd, 3rd, and 4th quintiles of the distribution, while high intake corresponds to the 5th quintile. Moderate value corresponds to the 2nd, 3rd, and 4th quintiles of the distribution, while high value corresponds to the 5th quintile.Ri is the proportion of the total variance due to between-study variance. Large values (>0.75) indicate high power of the corresponding significance test, while small values (<0.4) indicate that the test for heterogeneity is underpowered and may be deceptive if the number of studies is small (7).

  • a Results based on nine studies.

  • b Results based on two studies.