TABLE 2.
Pooled RRs of total cancer and cancer-specific mortality for the highest compared with lowest dairy consumption
| Characteristic | Studies (n) | RR (95% CI) | Heterogeneity | P-difference |
|---|---|---|---|---|
| Total dairy | ||||
| All studies | 13 | 0.99 (0.95, 1.03) | I 2 = 24.9%, P = 0.20 | |
| Sex | ||||
| Male | 2 | 1.03 (0.94, 1.12) | I 2 = 24.8%, P = 0.25 | 0.78 |
| Female | 5 | 1.02 (0.96, 1.08) | I 2 = 23.6%, P = 0.26 | |
| Cancer site | ||||
| Gastrointestinal tract | 7 | 0.89 (0.71, 1.12) | I 2 = 30.9%, P = 0.22 | |
| Stomach | 2 | 1.26 (0.72, 2.23) | I 2 = 0%, P = 0.80 | |
| Colorectal | 5 | 0.83 (0.63, 1.10) | I 2 = 54.6%, P = 0.11 | |
| Pancreatic cancer | 3 | 1.06 (0.86, 1.31) | — | 0.411 |
| Lung cancer | 5 | 0.79 (0.47, 1.32) | I 2 = 79.5%, P = 0.01 | 0.891 |
| Women's cancer | 2 | 1.06 (0.92, 1.23) | I 2 = 0%, P = 0.83 | 0.271 |
| Prostate cancer | 8 | 1.11 (0.99, 1.25) | I 2 = 0%, P = 0.7 | 0.101 |
| Fat content | ||||
| High-fat dairy | 2 | 0.92 (0.69, 1.23) | I 2 = 77.8%, P = 0.03 | 0.99 |
| Low-fat dairy | 3 | 0.96 (0.89, 1.03) | I 2 = 0%, P = 0.61 | |
| Geographic region | ||||
| United States | 8 | 1.02 (0.98, 1.06) | I 2 = 0%, P = 0.61 | |
| Asia | 3 | 0.82 (0.66, 1.02) | I 2 = 0%, P = 0.89 | 0.092 |
| Europe | 1 | 0.91 (0.84, 0.98) | — | 0.042 |
| Oceania | 1 | 0.94 (0.42, 2.11) | — | 0.852 |
| Adjustment for covariates3 | ||||
| Strong adjustment | 6 | 1.00 (0.94, 1.06) | I 2 = 0%, P = 0.60 | 0.88 |
| Weak adjustment | 7 | 0.98 (0.92, 1.05) | I 2 = 60.1%, P = 0.04 | |
| Milk | ||||
| All studies | 17 | 1.04 (0.99, 1.08) | I 2 = 65.8%, P < 0.001 | |
| Sex | ||||
| Male | 5 | 1.00 (0.94, 1.07) | I 2 = 39.1%, P = 0.16 | 0.19 |
| Female | 6 | 1.10 (1.01, 1.21) | I 2 = 71.4%, P = 0.004 | |
| Cancer site | ||||
| Upper digestive tract | 2 | 1.17 (0.71, 1.94) | I 2 = 77.9%, P = 0.004 | |
| Esophageal | 2 | 1.80 (0.53, 6.04) | I 2 = 86.8%, P = 0.006 | |
| Gastrointestinal tract | 12 | 0.97 (0.88, 1.06) | I 2 = 20.7%, P = 0.20 | 0.474 |
| Stomach | 6 | 1.06 (0.80, 1.41) | I 2 = 39.5%, P = 0.13 | |
| Colorectal | 9 | 0.96 (0.87, 1.07) | I 2 = 21.4%, P = 0.23 | |
| Hepatobiliary system | 7 | 1.07 (1.00, 1.14) | I 2 = 0%, P = 0.94 | 0.934 |
| Liver | 3 | 1.13 (1.02, 1.26) | I 2 = 0%, P = 0.82 | |
| Pancreatic | 6 | 1.06 (0.96, 1.18) | I 2 = 0%, P = 0.99 | |
| Respiratory tract | 10 | 1.03 (0.92, 1.15) | I 2 = 27.7%, P = 0.17 | 0.804 |
| Lung | 10 | 1.03 (0.90, 1.17) | I 2 = 34.4%, P = 0.13 | |
| Women's cancer | 5 | 1.13 (1.01, 1.26) | I 2 = 35.5%, P = 0.15 | 0.564 |
| Breast | 4 | 1.02 (0.91, 1.14) | I 2 = 0%, P = 0.52 | |
| Ovarian | 4 | 1.32 (1.13, 1.55) | I 2 = 0%, P = 0.78 | |
| Prostate cancer | 5 | 1.23 (1.02, 1.48) | I 2 = 49.8%, P = 0.09 | 0.274 |
| Urological system | 2 | 1.05 (0.52, 2.11) | I 2 = 90.9%, P < 0.001 | 0.604 |
| Fat content5 | ||||
| High/whole-fat milk | 6 | 1.17 (1.07, 1.28) | I 2 = 45.0%, P = 0.14 | 0.02 |
| Low/skimmed milk | 6 | 1.01 (0.96, 1.05) | I 2 = 0%, P = 0.40 | |
| Geographic region | ||||
| United States | 6 | 1.04 (0.98, 1.09) | I 2 = 64.1%, P = 0.04 | |
| Asia | 6 | 1.02 (0.95, 1.09) | I 2 = 60.2%, P = 0.01 | 0.736 |
| Europe | 5 | 1.06 (0.90, 1.26) | I 2 = 79.9%, P = 0.001 | 0.746 |
| Adjustment for covariates | ||||
| Strong adjustment | 6 | 1.09 (0.97, 1.22) | I 2 = 82.6%, P < 0.001 | 0.25 |
| Weak adjustment | 11 | 1.02 (0.99, 1.06) | I 2 = 37.6%, P = 0.10 | |
| Fermented milk | ||||
| All studies | 10 | 0.95 (0.89, 1.01) | I 2 = 45.9%, P = 0.05 | |
| Sex | ||||
| Male | 3 | 0.96 (0.80, 1.14) | I 2 = 55.8%, P = 0.10 | 0.27 |
| Female | 3 | 0.85 (0.77, 0.94) | I 2 = 0%, P = 0.68 | |
| Cancer site | ||||
| Gastrointestinal tract | 5 | 0.91 (0.79, 1.04) | I 2 = 0%, P = 0.59 | |
| Stomach | 2 | 1.34 (0.67, 2.69) | I 2 = 0%, P = 0.45 | |
| Colorectal | 5 | 0.89 (0.78, 1.03) | I 2 = 0%, P = 0.59 | |
| Hepatobiliary system | 2 | 1.16 (0.50, 2.72) | I 2 = 0%, P = 0.56 | 0.587 |
| Pancreatic | 2 | 0.81 (0.29, 2.22) | I 2 = 0%, P = 0.82 | |
| Lung cancer | 3 | 0.87 (0.65, 1.17) | I 2 = 0%, P = 0.82 | 0.807 |
| Ovarian cancer | 1 | 1.66 (0.71, 3.90) | — | 0.197 |
| Prostate cancer | 1 | 0.78 (0.25, 2.47) | — | 0.807 |
| Urothelial cancer | 1 | 0.72 (0.33, 1.57) | — | 0.577 |
| Geographic region | ||||
| United States | 3 | 0.98 (0.88, 1.08) | I 2 = 71.2%, P = 0.03 | |
| Asia | 3 | 0.85 (0.71, 1.03) | I 2 = 0%, P = 0.60 | 0.508 |
| Europe | 4 | 0.93 (0.85, 1.02) | I 2 = 20.6%, P = 0.29 | 0.278 |
| Adjustment for covariates | ||||
| Strong adjustment | 5 | 0.94 (0.87, 1.02) | I 2 = 54.0%, P = 0.07 | 0.82 |
| Weak adjustment | 5 | 0.95 (0.84, 1.08) | I 2 = 36.8%, P = 0.16 | |
| Cheese | ||||
| All studies | 10 | 0.99 (0.98, 1.01) | I 2 = 0%, P = 0.79 | |
| Sex | ||||
| Male | 3 | 1.00 (0.89, 1.12) | I 2 = 13.9%, P = 0.31 | 0.63 |
| Female | 4 | 1.04 (0.95, 1.14) | I 2 = 0.3%, P = 0.39 | |
| Cancer site | ||||
| Gastrointestinal tract | 6 | 1.22 (1.02, 1.45) | I 2 = 0%, P = 0.85 | |
| Colorectal | 6 | 1.22 (1.02, 1.46) | I 2 = 0%, P = 0.66 | |
| Pancreatic cancer | 4 | 1.25 (0.89, 1.76) | I 2 = 0%, P = 0.69 | 0.899 |
| Lung cancer | 6 | 0.85 (0.63, 1.15) | I 2 = 41.5%, P = 0.13 | 0.039 |
| Women's cancer | 4 | 1.15 (0.93, 1.44) | I 2 = 0%, P = 0.86 | 0.729 |
| Breast | 3 | 1.16 (0.88, 1.53) | I 2 = 0%, P = 0.63 | |
| Ovarian | 3 | 1.24 (0.81, 1.90) | I 2 = 0%, P = 0.50 | |
| Prostate cancer | 3 | 1.17 (0.89, 1.55) | I 2 = 0%, P = 0.53 | 0.849 |
| Urothelial cancer | 1 | 0.91 (0.68, 1.21) | — | 0.119 |
| Geographic region | ||||
| United States | 4 | 0.99 (0.97, 1.01) | I 2 = 0%, P = 0.45 | |
| Asia | 2 | 1.00 (0.80, 1.24) | I 2 = 0%, P = 0.95 | 0.9610 |
| Europe | 4 | 1.04 (0.96, 1.13) | I 2 = 0%, P = 0.47 | 0.2710 |
| Adjustment for covariates | ||||
| Strong adjustment | 5 | 0.99 (0.97, 1.01) | I 2 = 0%, P = 0.49 | 0.35 |
| Weak adjustment | 5 | 1.04 (0.95, 1.14) | I 2 = 0%, P = 0.97 |
P value for difference in RRs of total dairy consumption for hepatobiliary system compared with gastrointestinal tract, lung cancer compared with gastrointestinal tract, women's cancer compared with gastrointestinal tract, and prostate cancer compared with gastrointestinal tract.
P value for difference in RRs of total dairy consumption for Asia compared with United States, Europe compared with United States, and Oceania compared with United States.
Adjustment for at least age, BMI, energy intake, alcohol intake, smoking status, physical activity, and socioeconomic status is considered strong adjustment. Otherwise, it is considered weak adjustment.
P value for difference in RRs of milk consumption for gastrointestinal tract compared with upper digestive tract, hepatobiliary system compared with upper digestive tract, respiratory tract compared with upper digestive tract, women's cancer compared with upper digestive tract, prostate cancer compared with upper digestive tract, and urological system compared with upper digestive tract.
Milk fat content ≥3.5% was defined as high/whole-fat milk, and milk fat content <3.5% was defined as low-fat milk.
P value for difference in RRs of milk consumption for Asia compared with United States and Europe compared with United States.
P value for difference in RRs of fermented milk consumption for hepatobiliary system compared with gastrointestinal tract, lung cancer compared with gastrointestinal tract, ovarian cancer compared with gastrointestinal tract, prostate cancer compared with gastrointestinal tract, and urothelial cancer compared with gastrointestinal tract.
P value for difference in RRs of fermented milk consumption for Asia compared with United States and Europe compared with United States.
P value for difference in RRs of cheese consumption for pancreatic cancer compared with gastrointestinal tract, lung cancer compared with gastrointestinal tract, women's cancer compared with gastrointestinal tract, prostate cancer compared with gastrointestinal tract, and urothelial cancer compared with gastrointestinal tract.
P value for difference in RRs of cheese consumption for Asia compared with United States and Europe compared with United States.