Table 3.
Geometric mean (95% confidence interval) breast density according to tertile of erythrocyte PUFA compositiona
| Fatty acids (wt %) | Percent Densityb | P trendc | Dense Breast Areab | P trendc |
|---|---|---|---|---|
| n-6 PUFAs | ||||
| Total n-6 d | 0.26 | 0.66 | ||
| ≤37.28 | 24.2 (20.6, 28.0) | 35.8 (30.3, 41.8) | ||
| 37.29–39.49 | 23.6 (20.2, 27.3) | 33.9 (28.7, 39.6) | ||
| ≥39.50 | 27.4 (23.6, 31.4) | 37.7 (32.1, 43.9) | ||
| 18:2n-6 (LA) | 0.30 | 0.18 | ||
| ≤14.69 | 27.3 (23.5, 31.4) | 38.6 (32.9, 44.8) | ||
| 14.70–16.77 | 23.5 (20.1, 27.2) | 36.0 (30.5, 41.8) | ||
| ≥16.78 | 24.4 (20.8, 28.1) | 33.0 (27.8, 38.7) | ||
| 20:4n-6 (AA) | 0.07 | 0.16 | ||
| ≤15.31 | 22.8 (19.5, 26.4) | 32.1 (27.0, 37.6) | ||
| 15.32–16.57 | 24.6 (21.1, 28.4) | 37.9 (32.4, 43.9) | ||
| ≥16.58 | 27.7 (23.9, 31.8) | 37.5 (31.9, 43.6) | ||
| n-3 PUFAs | ||||
| Total n-3 e | 0.36 | 0.47 | ||
| ≤6.68 | 25.7 (22.0, 29.7) | 37.3 (31.6, 43.5) | ||
| 6.69–8.42 | 26.3 (22.7, 30.1) | 36.1 (30.7, 41.9) | ||
| ≥8.43 | 23.2 (19.7, 26.9) | 34.2 (28.7, 40.0) | ||
| 18:3n-3 (ALA) | 0.20 | 0.25 | ||
| ≤0.19 | 27.1 (23.5, 31.1) | 38.3 (32.8, 44.3) | ||
| 0.20–0.25 | 24.2 (20.7, 27.9) | 35.4 (30.0, 41.2) | ||
| ≥0.26 | 23.7 (20.3, 27.4) | 33.7 (28.5, 39.4) | ||
| 20:5n-3 (EPA) | 0.17 | 0.17 | ||
| ≤0.66 | 25.0 (21.5, 28.8) | 36.8 (31.3, 42.8) | ||
| 0.67–0.91 | 29.0 (25.2, 33.1) | 39.9 (34.2, 46.0) | ||
| ≥0.92 | 21.4 (18.1, 24.9) | 31.1 (26.1, 36.7) | ||
| 22:6n-3 (DHA) | 0.58 | 0.99 | ||
| ≤3.67 | 25.0 (21.4, 28.9) | 35.3 (29.8, 41.3) | ||
| 3.68–4.93 | 26.5 (22.8, 30.4) | 36.8 (31.4, 42.7) | ||
| ≥4.94 | 23.6 (20.1, 27.3) | 35.3 (29.9, 41.2) | ||
| 6:3 PUFA Ratios | ||||
| Total n-6:n-3 | 0.12 | 0.41 | ||
| ≤4.47 | 21.9 (18.5, 25.6) | 33.4 (28.1, 39.3) | ||
| 4.48–5.73 | 26.9 (23.3, 30.8) | 37.0 (31.6, 42.9) | ||
| ≥5.74 | 26.2 (22.5, 30.2) | 37.0 (31.3, 43.1) | ||
| LA:ALA | 0.45 | 0.57 | ||
| ≤64.25 | 24.7 (21.2, 28.4) | 36.0 (30.6, 41.8) | ||
| 64.26–78.43 | 23.8 (20.3, 27.4) | 33.3 (28.1, 38.9) | ||
| ≥78.44 | 26.7 (23.0, 30.7) | 38.4 (32.7, 44.5) | ||
| AA:EPA+DHA | 0.12 | 0.23 | ||
| ≤2.67 | 22.3 (18.9, 26.0) | 33.4 (28.0, 39.2) | ||
| 2.68–3.72 | 26.3 (22.7, 30.1) | 35.6 (30.3, 41.4) | ||
| ≥3.73 | 26.5 (22.8, 30.5) | 38.5 (32.8, 44.6) | ||
Abbreviations: PUFA, polyunsaturated fatty acid; n-6, omega-6; LA, linoleic acid; AA, arachidonic acid; n-3, omega-3; ALA, alpha-linolenic acid; EPA, eicosapentaenoic acid; and DHA, docosahexaenoic acid.
Square root transformation was applied to percent density and dense breast area. Values were adjusted for age (continuous), BMI (continuous), age at menopause (continuous), age at menarche (<12, 12–13, 14+), alcohol intake (none, <12g/day, ≥12g/day), current smoker (yes vs. no), previous breast biopsy (yes vs. no), nulliparous (yes vs. no), ever breastfed for > 1 month (yes vs. no), and past hormone therapy use (yes vs. no). 7 participants were excluded for missing variables.
Linear trend tests were performed by treating the fatty acid tertile groups as ordinal variables
18:2n-6 + 18:3n-6 + 20:2n-6 + 20:3n-6 + 20:4n-6 + 22:4n-6 + 22:5n-6
18:3n-3 + 20:4n-3 + 20:5n-3 + 22:5n-3 + 22:6n-3