Table 1.
Age-standardized* characteristics of participants according to quintiles of branched chain amino acid (BCAA) intake in Nurses’ Health Study (NHS), Nurses’ Health Study II (NHS II) and Health Professionals Follow-up Study (HPFS)
| NHS | HPFS | NHSII | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Q1 | Q3 | Q5 | Q1 | Q3 | Q5 | Q1 | Q3 | Q5 | |
| BCAA intake (g/d) | |||||||||
| Total BCAA | 10.1 (0.9) | 12.7 (0.3) | 15.6 (1.2) | 12.4 (1.1) | 15.6 (0.3) | 19.5 (1.8) | 11.6 (1.2) | 14.9 (0.4) | 18.4 (1.6) |
| Valine | 3.0 (0.3) | 3.7 (0.1) | 4.5 (0.4) | 3.6 (0.3) | 4.6 (0.1) | 5.7 (0.5) | 3.4 (0.3) | 4.4 (0.1) | 5.4 (0.5) |
| Leucine | 4.5 (0.4) | 5.6 (0.1) | 6.9 (0.5) | 5.5 (0.5) | 6.9 (0.2) | 8.6 (0.8) | 5.1 (0.5) | 6.6 (0.2) | 8.1 (0.7) |
| Isoleucine | 2.7 (0.3) | 3.4 (0.1) | 4.2 (0.4) | 3.3 (0.3) | 4.1 (0.1) | 5.2 (0.5) | 3.1 (0.3) | 3.9 (0.13) | 4.9 (0.5) |
| Age, (year) | 63.0 (10.9) | 62.3 (10.4) | 62.6 (10.0) | 64.0 (11.6) | 64.0 (11.1) | 62.6 (10.8) | 45.2 (8.4) | 45.2 (8.3) | 45.4 (8.3) |
| Body Mass Index (kg/m2) | 24.6 (4.4) | 25.6 (4.7) | 27.0 (5.1) | 25.3 (3.2) | 25.8 (3.3) | 26.4 (3.9) | 24.5 (5.3) | 25.5 (5.5) | 26.8 (6.0) |
| Alcohol drinkers (%) | 74 | 78 | 73 | 82 | 84 | 77 | 62 | 67 | 76 |
| Current smoker (%) | 18 | 13 | 11 | 7 | 5 | 5 | 12 | 9 | 9 |
| Family history of colorectal cancer (%) | 16 | 17 | 16 | 14 | 14 | 13 | 11 | 11 | 11 |
| History of endoscopy (%) | 18 | 21 | 21 | 23 | 25 | 23 | 12 | 13 | 12 |
| Regular aspirin or NSAID use (%) | 40 | 42 | 43 | 45 | 49 | 44 | 40 | 42 | 40 |
| Physical activity, MET-hours/wk | 14.7 (17.1) | 16.1 (16.6) | 17.8 (18.9) | 25.3 (24.0) | 26.4 (22.5) | 24.8 (23.3) | 21.4 (25.7) | 21.4 (23.2) | 23.5 (25.9) |
| Multivitamin use (%) | 50 | 55 | 58 | 45 | 48 | 45 | 29 | 32 | 32 |
| Postmenopausal (%) | 85 | 85 | 85 | - | - | - | 26 | 26 | 26 |
| Current PMH use (%) | 27 | 31 | 31 | - | - | - | 18 | 18 | 17 |
| Dietary intake | |||||||||
| Total energy intake (kcal/d) | 1733 (482) | 1766 (451) | 1696 (439) | 1963 (560) | 2003 (543) | 1927 (567) | 1799 (528) | 1826 (495) | 1761 (486) |
| Total protein (g/d) | 58.8 (5.3) | 72.5 (2.2) | 87.7 (6.9) | 72.6 (6.4) | 89.9 (2.6) | 110.5 (10.1) | 67.1 (6.6) | 84.5 (2.8) | 102.9 (9.0) |
| Animal protein (g/d) | 38.6 (6.2) | 51.9 (3.7) | 67.5 (8.2) | 46.3 (8.7) | 63.5 (5.2) | 85.2 (11.9) | 43.3 (9.0) | 61.0 (4.9) | 80.3 (10.6) |
| Plant protein (g/d) | 20.3 (4.4) | 20.6 (3.5) | 20.2 (3.8) | 26.3 (6.8) | 26.4 (5.3) | 25.4 (5.8) | 23.7 (6.5) | 23.3 (4.4) | 22.4 (4.5) |
| Dietary fiber (g/d) | 16.7 (4.9) | 17.8 (4.3) | 18.6 (4.7) | 21.4 (7.3) | 22.2 (6.1) | 22.5 (6.8) | 18.4 (6.2) | 18.8 (4.7) | 19.0 (5.0) |
| Folate (μg/d) | 410 (197) | 450 (191) | 495 (207) | 581 (324) | 617 (320) | 617 (343) | 445 (258) | 468 (244) | 504 (268) |
| Vitamin D (IU/d) | 290 (197) | 360 (199) | 456 (228) | 346 (240) | 425 (243) | 541 (309) | 317 (216) | 385 (208) | 481 (247) |
| Calcium (mg/d) | 866 (372) | 1032 (375) | 1230 (436) | 795 (318) | 928 (333) | 1081 (449) | 915 (384) | 1079 (383) | 1261 (451) |
| Unprocessed red meat (svg/d) | 0.5 (0.2) | 0.6 (0.3) | 0.6 (0.4) | 0.5 (0.3) | 0.6 (0.4) | 0.6 (0.5) | 0.4 (0.3) | 0.6 (0.3) | 0.6 (0.4) |
| Processed red meat (svg/d) | 0.3 (0.3) | 0.3 (0.2) | 0.2 (0.2) | 0.3 (0.4) | 0.3 (0.3) | 0.3 (0.3) | 0.2 (0.2) | 0.2 (0.2) | 0.2 (0.2) |
| Fish (svg/d) | 0.2 (0.1) | 0.3 (0.2) | 0.4 (0.3) | 0.2 (0.2) | 0.3 (0.2) | 0.5 (0.4) | 0.1 (0.1) | 0.2 (0.2) | 0.3 (0.3) |
| Chicken and Poultry (svg/d) | 0.2 (0.1) | 0.3 (0.2) | 0.5 (0.3) | 0.2 (0.2) | 0.4 (0.2) | 0.6 (0.4) | 0.9 (0.8) | 1.2 (0.9) | 1.5 (0.9) |
| Dairy products (svg/d) | 2.1 (1.4) | 2.4 (1.3) | 2.7 (1.4) | 1.8 (1.3) | 2.2 (1.3) | 2.5 (1.6) | 1.6 (1.1) | 2.1 (1.2) | 2.4 (1.4) |
*
Weighted by person years and age-standardized except for age.
Continuous variables shows as mean (standard deviation).
Abbreviations: BCAA: branched chain amino acid, NHS: Nurses’ Health Study, NHS II: Nurses’ Health Study II, HPFS: Health Professionals Follow-up Study NSAIDs: nonsteroidal anti-inflammatory drugs, PMH: postmenopausal hormone
Regular aspirin use was defined as use of 2 or more tablets per week. Dietary intake was energy-adjusted.