Table 1.
The effects of natural dietary products against gastric cancer from epidemiological studies.
| Natural Products | Phytochemicals | Subjects | Study Type | Consumed Levels | Effects | Ref. |
|---|---|---|---|---|---|---|
| Fruits | ||||||
| Citrus fruits | NA | 217 Gastric cancer cases (mean age: 65.4; 151 men) and controls (mean age: 64.3; 265 men) in Iran | Case-control | ≥3 times/week vs. never or infrequently intake of citrus fruits | Reducing gastric cancer risk (OR, 0.31; 95% CI, 0.17–0.59) | [30] |
| Citrus fruits | NA | 120,852 Subjects in Netherlands (58,279 men and 62,573 women), 156 gastric cardia adenocarcinoma cases and 460 gastric noncardia adenocarcinoma cases; aged 55–69 years | Cohort study | The highest (median = 156 g/d) vs. the lowest quintile (median = 0 g/d) of citrus fruits | Reducing the risk of gastric noncardia cancer (RR, 0.38; 95% CI, 0.21–0.69) | [34] |
| Total fruits (except watermelon) | NA | 559,247 Chinese men in the cohort and 132 distal gastric cancer cases; aged 40–74 years | Cohort study | >104.2 vs. ≤20.1 g/d all fruits (except watermelon) | Reducing distal gastric cancer risk (HR, 0.50; 95% CI, 0.29–0.84) | [47] |
| Total fruits (except watermelon) | NA | 73,064 Chinese women in the cohort and 206 distal gastric cancer cases; aged 40–70 years | Cohort study | >208.0 vs. ≤61.5 g/d all fruits (except watermelon) | No association (HR, 1.02; 95% CI, 0.68–1.54) | |
| Total fruit | NA | 191,232 Japanese subjects, (87,771 men and 103,461 women) and 2995 gastric cancer cases (2104 men and 891 women) | Pooled analysis | The highest quintile vs. the lowest quintile of total fruit | No association (HR, 0.9; 95% CI, 0.67–1.22) | [44] |
| Vegetables | ||||||
| Brassica vegetables | NA | 120,852 Subjects in Netherlands (58,279 men and 62,573 women), 156 gastric cardia adenocarcinoma cases and 460 gastric noncardia adenocarcinoma cases; aged 55–69 years | Cohort study | The highest (median = 59 g/d) vs. the lowest quintile (median = 11 g/d) of Brassica vegetables | Reducing the risk of gastric noncardia cancer (RR, 0.51; 95% CI, 0.28–0.92) | [34] |
| Total vegetables | NA | 559,247 Chinese men in the cohort and 132 distal gastric cancer; aged 40–74 years | Cohort study | >429.3 vs. ≤212.9 g/d total vegetables | No association (HR, 1.00; 95% CI, 0.59–1.68) | [47] |
| Total vegetables | NA | 73,064 Chinese women in the cohort and 206 distal gastric cancer cases; aged 40–70 years | Cohort study | >373.7 vs. ≤179.5 g/d total vegetables | No association (HR, 0.89; 95% CI, 0.60–1.31) | |
| Total vegetables | NA | 191,232 Japanese subjects, (87,771 men and 103,461 women) and 2995 gastric cancer cases (2104 men and 891 women) | Pooled analysis | The highest quintile vs. the lowest quintile of total vegetable | Reducing distal gastric cancer risk in men (multivariate HR, 0.78; 95% CI, 0.63–0.97) | [44] |
| Fruits and vegetables | ||||||
| Fruits and vegetables | β-carotene | 511 Japanese gastric cancer cases (342 men) and 511 controls (342 men); aged 40–69 years | Nested case-control | ≥27.0 vs. ≤8.0 ug/dL β-carotene | Reducing gastric cancer risk (OR, 0.46; 95% CI, 0.28–0.75) | [39] |
| Vegetables, citrus fruits, and whole grains | NA | 970,045 American subjects (533,391 women and 436,654 men) and 439 women and 910 men died from gastric cancer | Cohort study | The highest vs. the lowest tertile of plant foods | Reducing gastric cancer risk in men (RR, 0.79; 95% CI, 0.67–0.93) | [35] |
| Fruits, vegetables and beverages | Quercetin | 505 Swedish gastric cancer cases (336 men) and 1116 controls (746 men); aged 40–79 years | Case-control | ≥11.9 vs. <4 mg /day quercetin | Reducing noncardia gastric adenocarcinoma risk (OR, 0.57; 95% CI, 0.40–0.83) | [19] |
| Spices | ||||||
| Allium vegetables | NA | 543,220 Total subjects | Meta-analysis | The highest vs. the lowest consumption category of allium vegetables | Reducing gastric cancer risk (OR, 0.54; 95% CI, 0.43–0.65) | [36] |
| Garlic | NA | 217 Gastric cancer cases (mean age: 65.4; 151 men) and controls (mean age: 64.3; 265 men) in Iran | Case-control | ≥3 times/week vs. never or infrequently intake of garlic | Reducing gastric cancer risk (OR, 0.35; 95% CI, 0.13–0.95) | [30] |
| Onion | NA | ≥ once per day vs. ≤2 times/week onion | Reducing gastric cancer risk (OR, 0.34; 95% CI, 0.19–0.62) | |||
| Soy and soy products | ||||||
| Soy | Isoflavone | 84,881 Japanese subjects (39,569 men and 45,312 women), 1249 gastric cancer cases; aged 45–74 years | Cohort study | The highest vs. the lowest quartile of isoflavone | No association (HR, 1.00; 95% CI, 0.81-1.24 for men and HR, 1.07; 0.77–1.50 for women) | [49] |
| Soy | Isoflavone | 30,792 Japanese subjects (14,219 men and 16,573 women), 678 gastric cancer cases (441 men and 237 women); aged ≥ 35 years | Cohort study | >53 vs. ≤28 mg/d isoflavone | Reducing gastric cancer risk in women (HR, 0.60; 95% CI, 0.37–0.98) | [18] |
| >122 vs. ≤62 g/d soy food | Reducing gastric cancer risk in men(HR, 0.71; 95% CI, 0.53–0.96) and women (HR, 0.58; 95% CI, 0.36–0.94) | |||||
| Tofu | NA | 128,687 Chinese subjects (70,446 women and 58,241 men), 493 distal gastric cancer cases; aged 40–74 years | Cohort study | >8.4 vs. <3.1 g/d tofu | Reducing distal gastric cancer risk in men (HR, 0.64; 95% CI, 0.42–0.99) | [38] |
| Dry bean | NA | >0.9 vs. 0.0 g/d dry bean | Reducing gastric cancer risk in postmenopausal women (HR, 0.63; 95% CI, 0.43–0.91) | |||
| Total soy product | NA | 30,304 Japanese subjects (13,880 men and 16,424 women) and 121 gastric cancer deaths; aged ≥ 35 years | Cohort study | The highest (median = 49.7 g/d) vs. the lowest tertile (median = 140 g/d) of total soy product | Reducing the risk of gastric cancer death (HR, 0.5; 95% CI, 0.26–0.93) | [28] |
| Cereals | ||||||
| Other | ||||||
| Flavonoids | 469,008 American subjects (275,982 men and 193,026 women), 1297 gastric cancer cases; aged 50–71 years | Cohort study | 438.0–4211.2 vs. 0–84.1 mg/d total flavonoids | No association (HR, 1.02; 95% CI, 0.78–1.34) for gastric cardia cancer; (HR, 1.11; 95% CI, 0.86–1.44) for gastric noncardia cancer | [50] | |
| Flavonoids | 334 Korean gastric cancer cases (208 men) and 334 controls (208 men); aged 35–75 years | Case-control study | The highest tertile (median = 152.3 mg/d) vs. the lowest tertile (median = 52.5 mg/d) of flavonoids | Reducing gastric cancer risk (OR, 0.49; 95% CI, 0.31–0.76) | [40] | |
| Anthocyanidins | 248 American gastric cardia cancer cases and 662 controls; aged 30–79 years | Case-control study | ≥18.48 vs. ≤7.21 mg/d anthocyanidins | Reducing the risk of mortality for gastric cardia cancer (HR, 0.63; 95% CI, 0.42–0.95) | [42] |
NA: not available.