Table 1.
Baseline characteristics by quintile of red meat intake in participants of the PLCO Cancer Screening Trial*
| Characteristics | Men (N = 48,229) | Women (N = 51,350) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | Q5 | Q1 | Q2 | Q3 | Q4 | Q5 | |
| Red meat intake† (range and median, g/1000 kcal) | ≤ 20.9 (14.5) | 21.0 – 31.0 (26.2) | 31.1 – 41.0 (35.8) | 41.1 – 54.8 (47.1) | > 54.8 (67.1) | ≤ 14.6 (9.4) | 14.6– 22.8 (18.8) | 22.9 – 31.0 (26.7) | 31.1– 42.5 (36.1) | > 42.5 (52.8) |
| Age (y) | 66.8~ | 66.3 | 65.9 | 65.3 | 64.5 | 66.0 | 65.8 | 65.3 | 64.9 | 64.5 |
| BMI (kg/m2) | 26.3 | 27.1 | 27.5 | 28.0 | 28.7 | 25.6 | 26.5 | 27.0 | 27.6 | 28.3 |
| 1st degree relative with cancer (%) | 51.8 | 51.9 | 52.6 | 53.3 | 53.3 | 59.9 | 60.2 | 60.5 | 60.6 | 59.7 |
| Race (%) | ||||||||||
| Non-Hispanic White | 84.5 | 90.7 | 92.6 | 92.8 | 93.3 | 85.4 | 91.0 | 92.6 | 93.5 | 93.8 |
| Non-Hispanic Black | 4.3 | 2.8 | 2.2 | 2.3 | 1.9 | 6.8 | 4.0 | 3.2 | 2.7 | 2.2 |
| Education, College graduate (%) | 51.4 | 44.8 | 41.9 | 38.6 | 33.7 | 38.8 | 32.5 | 31.5 | 28.1 | 22.9 |
| Smoking status (%) | ||||||||||
| Never smokers | 43.9 | 40.0 | 37.9 | 35.6 | 33.1 | 59.8 | 58.8 | 58.9 | 56.8 | 54.9 |
| Former smokers, quit ≥ 1y ago | 49.6 | 50.3 | 51.3 | 52.0 | 51.6 | 34.3 | 33.2 | 32.6 | 32.8 | 32.3 |
| Current/former smoker quit <1 y ago | 6.5 | 9.7 | 10.8 | 12.4 | 15.3 | 5.9 | 8.0 | 8.6 | 10.4 | 12.9 |
| Age at smoking initiation (y) | 18.2 | 17.9 | 17.8 | 17.8 | 17.6 | 19.6 | 19.7 | 19.4 | 19.5 | 19.4 |
| Packs-years | 33.5 | 36.4 | 38.0 | 39.2 | 43.3 | 25.8 | 28.0 | 28.5 | 30.1 | 32.3 |
| Time since cessation (%) | ||||||||||
| Quit ≥ 20 yrs ago | 61.8 | 57.6 | 56.9 | 55.0 | 49.5 | 56.4 | 52.3 | 51.1 | 47.5 | 43.8 |
| Quit <20 yrs and ≥ 10 yrs ago | 23.8 | 25.6 | 25.5 | 26.2 | 28.8 | 26.1 | 26.1 | 25.7 | 29.1 | 29.1 |
| Quit <10 yrs and ≥ 5 yrs ago | 8.6 | 9.9 | 10.1 | 11.1 | 12.1 | 10.3 | 12.9 | 14.1 | 13.9 | 15.7 |
| Quit <5 yrs and ≥ 1 yr ago | 5.9 | 6.8 | 7.5 | 7.8 | 9.6 | 7.2 | 8.0 | 9.2 | 9.6 | 11.4 |
| Married (%) | 82.9 | 85.8 | 86.4 | 86.0 | 84.8 | 61.7 | 69.2 | 73.6 | 76.3 | 78.8 |
| Dietary intake | ||||||||||
| Energy (kcal/d) | 1905 | 1930 | 1981 | 2023 | 2137 | 1476 | 1453 | 1495 | 1512 | 1546 |
| White meat‡ (g/1000 kcal) | 28.5 | 25.0 | 25.3 | 25.9 | 26.7 | 35.4 | 32.7 | 32.4 | 32.9 | 33.6 |
| Processed meat§ (g/1000 kcal) | 5.6 | 8.6 | 10.8 | 13.2 | 18.0 | 3.8 | 5.7 | 7.4 | 9.3 | 12.6 |
| Vegetables (servings/1000 kcal) | 1.1 | 1.0 | 1.0 | 1.0 | 1.0 | 1.4 | 1.3 | 1.3 | 1.3 | 1.3 |
| Fruits (servings/1000 kcal) | 1.3 | 1.0 | 0.9 | 0.8 | 0.7 | 1.7 | 1.4 | 1.3 | 1.2 | 0.9 |
| Total fat (g/1000 kcal) | 30.2 | 34.2 | 36.0 | 37.8 | 41.0 | 30.0 | 33.0 | 34.9 | 36.5 | 39.4 |
| Alcohol (servings/day) | 1.3 | 1.1 | 1.0 | 0.9 | 0.8 | 0.3 | 0.4 | 0.4 | 0.4 | 0.3 |
| β-carotene supplements (μg/day) | 217 | 173 | 165 | 147 | 138 | 243 | 208 | 188 | 180 | 170 |
P for trend < 0.01 for all variables except for age at smoking initiation (P = 0.02), alcohol intake (P = 0.39) and 1st degree relative with cancer (P = 0.99) in women, estimated by the Cohrain-Armitage tests for categorical variables and the t test for slope in generalized linear models for continuous variables.
Included bacon, beef (including meat added to mixed dishes, such as pizza, chili, lasagna, stew), cold cuts, ham, hamburger, regular hotdogs, liver, pork, sausage, and steak.
All forms of poultry (chicken, cold cuts, ground, turkey), fish (fresh, frozen, canned), and low-fat hotdogs and sausages, which are usually made from turkey.
All types of cold cuts, bacon, ham, hotdogs, and sausages from red and white meats.
Mean (all such values).