12 JOURNAL OF COSMETIC SCIENCE 20 ------------- 5 A R=0.7386 P0.01 • . . . • . •· . .. .........•···....•··...•.··.........•··········•.......•···········.•• . • • • • 0 ----"'---......ii.....--....i...--......1 0 1 2 3 SQ mg/g hair 4 0.6 --------------- � 0.2 � u B R=0.7716 P0.01 . . ..... • •• ,: . . ....·.....•·· . • • • . •· ..•·... .... •·� . •,... •· . . ....... . ·.•....• .. ····•••·· ... •· . . • • • • • • 0 . 0 ..__ ____ .,__ ____ .,__ _______. 0 1 2 CH mg/g hair 3 3-------------- ..... � 2 = 1 u • •. • C R= -0.6133 P0.01 • • • •···· - .. , .. ··· ····•.. .• . .:. ... . : ····· ·�·•. . . . . . ·• .. • . . ··•.. . • . . .... ··· • .... . 0 ._ __ ..._ ______ ......., __ ___. 0 5 10 15 WEs mg/g hair 20 Figure 7. The relationship between the levels of lipids from 44 Japanese females. Each point represents the level of the lipids for each individual. A: SQ and WEs. B: CH and CERs. C: WEs and CH.

HAIR LIPID COMPOSITION 13 Table III Factor Loading, Eigenvalue, Contribution, and Accumulated Contribution for Principal Components of Eight Lipids Lipid First Second Third HCs -0.022 0.728 0.155 SQ -0.411 -0.310 -0.201 WEs -0.425 -0.293 -0.183 Factor TGs -0.253 0.003 0.558 loading FAs -0.381 0.160 -0.405 CH 0.500 -0.133 -0.089 CERs 0.421 -0.353 -0.120 MEA 0.118 0.346 -0.636 Eigenvalue 3.386 1.444 1.196 Contribution (%) 42.3 18.1 15.0 Accumulated contribution (%) 42.3 60.4 75.3 Abbreviations: as described in Table I. 4 2 0 0 0 0 8 � 0 0 8 0 0 0 0 0 0 0 0 0 0 0 -2 - 0 0 -4 -2 Component Fourth -0.130 0.065 0.040 0.737 -0.124 0.070 0.171 0.620 0.709 8.9 84.2 0 Zl 0 0 0 0 Fifth -0.469 -0.364 -0.476 0.159 0.600 -0.170 0.003 -0.081 0.539 6.7 90.9 0 0 0 0 o8 0 Sixth Seventh Eighth 0.388 0.209 0.116 0.539 -0.455 -0.245 -0.325 0.443 0.412 0.134 0.012 0.194 0.345 0.111 0.400 0.132 -0.403 0.715 0.508 0.613 -0.140 -0.199 -0.052 -0.170 0.415 0.187 0.122 5.2 2.3 1.5 96.1 98.5 100.0 0 0 0 Ooooo 0 O 2 4 Figure 8. Two-dimensional projection of 44 Japanese females by the first two components (21 and 22) of PCA for the levels of eight lipids. Each point (0) represents the values of 21 and 22 for each individual. nantly accounted for 42.3% of the total variation (Table III, Figure 8). Individuals whose hair fibers contain lower lipid levels in group A and higher lipid levels in group B are distributed at the right-hand side of the projection in Figure 8. In contrast, individuals whose hair fibers contain higher lipid levels in group A and lower lipid levels in group B are distributed at the left-hand side of Figure 8. Distribution of the younger and older individuals according to their ages in the PCA, as shown Figure 9, suggests that the hair lipid composition may change with increasing age. Since lipids in group A (SQ, WEs, TGs, and FAs) are components similar to those of sebu� (28), it is likely that the lipids in group A result from sebum attributable to