Table 2: Trans fatty acids levels (% composition) by year

Fatty acid	2004 n = 95 (M = 25, F = 70)	2005 n = 234 (M = 80, F = 154)	2006 n = 227 (M = 69, F = 158)	2007 n = 137 (M = 34, F = 103)	2008 n = 203 (M = 52, F = 151)	2009 n = 201 (M = 136, F = 65)	2010 n = 197 (M = 71, F = 126)
16:1t9	0.33 ± 0.09*	0.30 ± 0.08*	0.19 ± 0.15‡	0.19 ± 0.13‡	0.21 ± 0.07‡	0.24 ± 0.09†	0.21 ± 0.08†,‡
18:1t4	0.05 ± 0.05†,‡	0.03 ± 0.04‡	0.08 ± 0.09*,†	0.10 ± 0.12*	0.09 ± 0.09*	0.08 ± 0.10*,†	0.09 ± 0.12*
18:1t5	0.03 ± 0.04†	0.02 ± 0.03†,‡	0.01 ± 0.02‡	0.01 ± 0.02‡	0.01 ± 0.01‡	0.03 ± 0.07†	0.09 ± 0.09*
18:1t6-8	0.21 ± 0.11*	0.15 ± 0.07†	0.08 ± 0.04‡	0.08 ± 0.04‡	0.08 ± 0.08‡	0.08 ± 0.08‡	0.15 ± 0.12†
18:1t9	0.42 ± 0.18*	0.25 ± 0.11†	0.21 ± 0.09‡	0.21 ± 0.07‡,§	0.16 ± 0.13¶	0.17 ± 0.10§,¶	0.38 ± 0.15*
18:1t10	0.44 ± 0.17*	0.31 ± 0.13‡	0.19 ± 0.09§	0.19 ± 0.10§	0.13 ± 0.13¶	0.23 ± 0.13§	0.37 ± 0.15†
18:1t11	0.31 ± 0.15*	0.29 ± 0.14*	0.24 ± 0.10†	0.23 ± 0.08†	0.16 ± 0.11‡	0.17 ± 0.09‡	0.12 ± 0.07§
18:1t12	0.24 ± 0.10*	0.19 ± 0.09†	0.13 ± 0.07‡	0.15 ± 0.07‡	0.09 ± 0.07§	0.14 ± 0.17‡	0.14 ± 0.10‡
18:1t13 or c6	0.18 ± 0.08*,†,‡	0.06 ± 0.16‡	0.16 ± 0.09†,‡	0.20 ± 0.08†,‡	0.22 ± 1.36†,‡	0.45 ± 1.17*	0.36 ± 0.48†
18:2c9t12	0.26 ± 0.06*,†	0.17 ± 0.04§	0.30 ± 0.34*	0.24 ± 0.09†,‡	0.19 ± 0.38‡,§	0.23 ± 0.10†,‡	0.26 ± 0.10*,†
18:2c9t13	0.21 ± 0.6*	0.17 ± 0.6*,†	0.19 ± 0.09*,†	0.16 ± 0.07†	0.04 ± 0.13§	0.07 ± 0.14§	0.11 ± 0.14‡
18:2t9c12	0.16 ± 0.04*,†	0.11 ± 0.05‡	0.16 ± 0.05†	0.16 ± 0.06†	0.12 ± 0.03‡	0.16 ± 0.08†	0.18 ± 0.07*
18:2t9t12	0.02 ± 0.01†,‡,§	0.01 ± 0.01§	0.03 ± 0.04†	0.03 ± 0.04†,‡	0.02 ± 0.02‡,§	0.04 ± 0.06†	0.10 ± 0.10*
18:2tt	0.02 ± 0.01§	0.03 ± 0.02§	0.04 ± 0.06‡,§	0.07 ± 0.20†	0.06 ± 0.03†,‡	0.05 ± 0.05†,‡,§	0.13 ± 0.13*
18:2c9t11 CLA	0.29 ± 0.07*	0.26 ± 0.07†	0.24 ± 0.06‡	0.20 ± 0.07‡,§	0.17 ± 0.06 e	0.17 ± 0.06 e	0.21 ± 0.11§
18:2c10t12 CLA	0.08 ± 0.02*	0.07 ± 0.02†,‡	0.06 ± 0.02‡,§	0.08 ± 0.04*,†	0.04 ± 0.02 e	0.06 ± 0.04§	0.07 ± 0.05*,†
Total trans	2.88 ± 0.88*	2.07 ± 0.70†	2.00 ± 0.69†	2.00 ± 0.63†	1.58 ± 1.50‡	2.12 ± 1.73†	2.69 ± 1.23*

Note: F = female, M = male. Values are expressed as mean ± standard deviation. Differences in years were analyzed by analysis of variance (ANOVA), and the Tukey posthoc test was used to determine differences between means. Total trans excludes conjugated linoleic acid isomers.Values within a row with different symbols are significantly different (p < 0.05).