Table 2.

Days on protocol, side effects, self-rated adherence, biomarkers of adherence, and nutrition-related changes in target tissues

Controls (n = 41)FS (n = 40)LF (n = 40)FS + LF (n = 40)P*
Days on protocol
    Median (95% CI)30 (22-29)31 (25-32)30 (25-29)30 (24-30)FS = 0.960/LF = 0.900
Side effects (grade 1/2/3 toxicity), %
    Nausea7/0/05/0/021/3/08/0/00.467
    Vomiting0/0/00/0/00/0/00/0/0NA
    Diarrhea5/3/018/0/06/0/014/0/00.308
Libido/impotence15/5/108/3/824/0/611/3/80.633
    Allergy0/3/00/0/00/0/00/3/00.436
Flaxseed (% of 30 g dose taken)
    Median (95% CI)NA97.5 (97.5-100)NA100 (100-100)
Dietary lignans (μg/d)
    Median (95% CI)
        Baseline253 (192-313)282 (217-320)263 (182-306)289 (223-310)FS < 0.0001/LF = 0.905
        Follow-up257 (219-292)260,935 (257,229-268,591)250 (227-329)262,402 (258,984-264,174)
Urinary lignans (ng/mg creatinine)
    Median (95% CI)
        Baseline257 (113-456)228 (147-609)308 (130-431)277 (197-447)FS < 0.0001/LF = 0.493
        Follow-up239 (123-473)10,566 (5,187-15,897)415 (194-754)10,358 (4,003-13,434)
Seminal fluid lignans (μg/mL)
Median (95% CI)
    Baseline182 (157-274)180 (162-266)202 (176-278)195 (139-244)FS = 0.013/LF = 0.797
    Follow-up262 (139-423)430 (202-535)293 (91-410)362 (137-701)
Energy intake
    Median (95% CI)
        Baseline2,187 (1,999-2,503)2,131 (1,749-2,572)1,769 (1,530-1,955)1,748 (1,439-2,392)FS = 0.591/LF = 0.068
        Follow-up1,959 (1,591-2,376)2,143 (1,715-2,654)1,689 (1,423-1,997)1,536 (1,370-1,929)
% Calories from fat
    Median (95% CI)
        Baseline34.6 (29.7-41.5)35.3 (32.5-37.9)36.4 (31.6-38.4)34.5 (32.4-38.6)FS = 0.092/LF < 0.0001
        Follow-up34.2 (29.7-39.7)34.0 (28.8-37.2)27.5 (25.2-31.7)24.8 (22.2-28.7)
Dietary ω3FA (% kcal)
    Median (95% CI)
        ALA (18.3)
        Baseline0.074 (0.067-0.082)0.072 (0.062-0.078)0.077 (0.064-0.087)0.076 (0.064-0.084)FS < 0.0001/LF = 0.469
        Follow-up0.076 (0.067-0.090)0.315 (0.260-0.392)0.064 (0.059-0.074)0.433 (0.334-0.474)
         EPA (20:5)
        Baseline0.000 (0.000-0.001)0.001 (0.001-0.002)0.001 (0.001-0.002)0.001 (0.001-0.002)FS = 0.701/LF = 0.005
        Follow-up0.001 (0.001-0.002)0.001 (0.001-0.002)0.002 (0.001-0.002)0.002 (0.001-0.005)
    Docosahexanoic acid (22:6)
        Baseline0.000 (0.000-0.001)0.001 (0.000-0.001)0.001 (0.000-0.001)0.001 (0.001-0.001)FS = 0.163/LF = 0.006
        Follow-up0.001 (0.001-0.001)0.001 (0.000-0.001)0.001 (0.001-0.001)0.001 (0.001-0.001)
Dietary ω6FA (% kcal)
    Median (95% CI)
        Linoleic acid (18:2)
        Baseline0.745 (0.623-0.867)0.705 (0.632-0.772)0.755 (0.645-0.876)0.799 (0.704-0.870)FS = 0.780/LF < 0.0001
        Follow-up0.782 (0.688-0.867)0.733 (0.679-0.803)0.582 (0.519-0.669)0.616 (0.587-0.686)
    Arachidonic acid (20:4)
        Baseline0.006 (0.005-0.007)0.006 (0.005-0.007)0.006 (0.005-0.007)0.006 (0.005-0.007)FS = 0.036/LF = 0.180
        Follow-up0.006 (0.005-0.007)0.005 (0.004-0.007)0.006 (0.005-0.007)0.005 (0.004-0.006)
Dietary ω3FA/ω6FA ratio
Median (95% CI)
    Baseline0.11 (0.10-0.12)0.10 (0.09-0.11)0.11 (0.10-0.12)0.11 (0.10-0.11)FS < 0.0001/LF = 0.0102
    Follow-up0.10 (0.10-0.12)0.46 (0.36-0.60)0.11 (0.11-0.12)0.71 (0.52-0.82)
Erythrocyte ω3FA (%)
Median (95% CI)
        ALA (18:3)
        Baseline0.000 (0.000-0.000)0.000 (0.000-0.000)0.000 (0.000-0.000)0.000 (0.000-0.000)FS = 0.520/LF = 0.290
        Follow-up0.000 (0.000-0.000)0.000 (0.000-0.000)0.000 (0.000-0.000)0.000 (0.000-0.000)
     EPA (20:5)
        Baseline0.633 (0.539-0.765)0.723 (0.581-0.941)0.651 (0.440-0.890)0.664 (0.613-0.793)FS = 0.005/LF = 0.705
        Follow-up0.651 (0.533-0.793)0.784 (0.651-0.890)0.475 (0.372-0.620)0.825 (0.702-1.101)
    Docosahexanoic acid (22:6)
        Baseline5.95 (5.54-6.64)6.01 (4.73-6.80)5.62 (4.55-6.53)5.82 (5.00-6.32)FS = 0.077/LF = 0.320
        Follow-up6.03 (5.01-7.09)5.51 (4.05-6.72)4.92 (4.36-6.38)6.07 (5.43-7.08)
Erythrocyte ω6FA (%)
Median (95% CI)
    Linoleic acid (18:2)
        Baseline11.11 (10.30-11.72)11.04 (10.03-12.11)11.05 (9.99-11.85)11.09 (10.14-11.45)FS = 0.544/LF = 0.037
        Follow-up10.46 (9.23-11.53)10.83 (9.73-11.53)9.71 (8.39-11.64)9.94 (9.32-10.83)
    Arachidonic acid (20:4)
        Baseline0.347 (0.292-0.371)0.368 (0.293-0.428)0.290 (0.230-0.419)0.336 (0.279-0.391)FS = 0.650/LF = 0.250
        Follow-up0.294 (0.218-0.337)0.358 (0.259-0.390)0.303 (0.217-0.357)0.324 (0.269-0.380)
Erythrocyte ω3FA/ω6FA ratio
    Median (95% CI)
    Baseline0.60 (0.49-0.72)0.62 (0.50-0.71)0.55 (0.44-0.72)0.56 (0.48-0.66)FS = 0.480/LF = 0.090
    Follow-up0.61 (0.47-0.78)0.54 (0.42-0.76)0.50 (0.39-0.76)0.64 (0.59-0.78)
Prostatic ω3FA (%)
    Median (95% CI)
        ALA (18:3)
        Follow-up0.000 (0.000-0.000)0.000 (0.000-0.000)0.000 (0.000-0.000)0.000 (0.000-0.000)FS = 0.662/LF = 0.924
    EPA (20:5)
        Follow-up0.216 (0.148-0.268)0.300 (0.221-0.385)0.195 (0.133-0.259)0.298 (0.245-0.428)FS = 0.010/LF = 0.970
    Docosahexanoic acid (22:6)
        Follow-up3.53 (3.11-4.27)3.68 (3.17-4.53)3.05 (3.34-4.21)3.94 (3.37-4.37)FS = 0.580/LF = 0.130
Prostatic ω6FA (%)
    Median (95% CI)
    Linoleic acid (18:2)
        Follow-up9.50 (8.99-10.28)9.48 (8.47-10.66)9.37 (8.34-10.52)9.47 (8.75-10.35)FS = 0.210/LF = 0.820
    Arachidonic acid (20:4)
        Follow-up0.269 (0.235-0.307)0.247 (0.221-0.295)0.259 (0.235-0.274)0.241 (0.231-0.285)FS = 0.230/LF = 0.760
Prostatic ω3FA/ω6FA ratio
    Median (95% CI)
        Follow-up0.40 (0.32-0.45)0.42 (0.34-0.50)0.42 (0.34-0.48)0.43 (0.38-0.47)FS = 0.175/LF = 0.974
  • NOTE: Average dose of flaxseed compared with amount prescribed and/or percentage of days adhered to <20% of kilocalories from fat.

  • * For factors that have both baseline and follow-up data, factorial testing was done under intent-to-treat analysis on change scores and P values are reported for both FS and LF conditions.

  • Note that seminal fluid was unavailable on several participants; the numbers of samples for baseline and follow-up among the study arms are as follows: control, n = 19 and n = 13; FS, n = 17 and n = 12; LF, n = 22 and n = 10; and FS + LF, n = 16 and n = 10, respectively.