Table 3.

Characteristics of female participants in the AGES-Reykjavik Study by weekly fish intake in adolescence and midlife

Fish intake in adolescenceFish intake in midlife
≤2 portions>2 up to 4 portions>4 portions≤2 portions>2 up to 4 portions>4 portions
(n = 1,425)(n = 311)(n = 1,146)Pa(n = 326)(n = 1,781)(n = 772)Pa
Age at study entry
 Mean (SD)76.2(5.6)77.3(6.0)76.55.50.01374.8(5.4)76.2(5.6)77.6(5.6)0.001
 Median767776747677
Age at diagnosis
 Mean (SD)80.3(6.1)80.3(5.4)81.3(6.6)0.78475.6(3.2)81.5(6.2)81.9(5.9)0.003
 Median807882758282
Heightb (cm)
 Mean (SD)164.1(5.4)164.4(5.6)164.1(5.3)0.643164.5(5.3)164.2(5.4)164.0(5.3)0.312
 Median164164.5164164.5164164
BMIb (kg/m2)
 Mean (SD)24.8(3.6)24.8(4.4)25.1(3.8)0.07325.0(4.05)24.9(3.7)25.0(3.9)0.860
 Median24.32424.52424.424.3
Education, n (%)
 Primary592(42)121(39)524(46)0.116163(50)755(42)317(41)0.005
 Secondary626(44)147(47)475(41)138(42)765(43)345(45)
 University/College207(14)43(14)147(13)25(8)261(15)110(14)
Birth cohort, n (%)
 1907–1919143(10)50(16)128(11)0.07123(7)180(10)117(15)0.001
 1920–1924324(23)75(24)267(23)52(16)405(23)208(27)
 1925–1929452(32)89(29)371(32)104(32)563(32)245(32)
 1930–1935506(36)97(31)380(33)147(45)633(36)202(26)
Age at menarche, n (%)
 ≤13 y639(45)148(48)502(44)0.469147(45)789(44)350(45)0.900
 ≥14 y784(55)162(52)643(56)179(55)988(56)422(55)
Ever pregnant, n (%)
 Yes1308(92)286(93)1068(93)0.464300(92)1638(92)721(94)0.488
Age at birth of first child, n (%)
 ≤24 y832(59)177(58)739(65)0.023204(64)1080(61)462(61)0.489
 ≥25 y457(33)106(35)318(28)88(28)545(31)247(33)
Physical activity, n (%)
 Never639(48)133(46)520(48)0.894154(51)837(50)301(42)0.001
 Rarely/occasionally289(22)67(23)224(21)76(25)354(21)150(21)
 Moderate/high393(30)87(30)329(31)73(24)474(29)261(37)
Family history of breast cancer, n (%)
 Yes240(17)50(16)188(16)0.92665(20)292(16)121(16)0.206
Meat consumption, n (%)
 2 times and less p/w606(43)166(53)186(16)0.001113(35)671(38)418(54)0.001
 3 times and more p/w808(57)144(47)956(84)211(65)1105(62)352(46)
Milk consumption, n (%)
 Less than daily371(26)67(22)256(22)0.045161(50)777(44)308(40)0.009
 Daily and more1046(74)243(78)887(78)160(50)996(56)460(60)
Rye consumption, n (%)
 Less than daily778(55)142(46)532(47)0.001246(76)1236(69)435(57)0.001
 Daily or more632(45)168(54)606(53)79(24)542(31)334(43)
Fish liver oil consumption, n (%)
 Less than daily640(45)139(45)454(40)0.017124(38)604(34)221(29)0.005
 Daily and more778(55)171(55)690(60)202(62)1172(66)546(71)
Salted fish consumption, n (%)
 3 times a month or less728(52)169(55)491(43)0.001268(83)1275(72)471(61)0.001
 Once a week or more684(48)141(46)641(57)57(17)495(28)297(39)
Consumption of alcohol, n (%)
 Yes223(69)1067(60)428(56)0.001
Ever use HRT, n (%)
 Yes99(31)486(28)210(28)0.536
Ever use oral contraceptives, n (%)
 Yes122(38)512(29)198(26)0.001
  • Abbreviation: HRT, hormone replacement therapy.

  • aP values are based on χ2 tests, except for length of residence, age at entry, age at diagnosis, height and BMI, where one-way ANOVA test was used.

  • bInformation retrieved upon entry into the Reykjavik Study.