FAs were analyzed in total lipid fractions for all pools except plasma, which was further separated into phosphatidylcholine, CEs, NEFAs and triglycerides. Total lipid was extracted into chloroform:methanol (2:1, vol:vol) from plasma, MNCs, RBCs, platelets, BUs, and homogenized AT; butylated hydroxytoluene (50 mg/L) was added as an antioxidant. Plasma lipid fractions were separated and isolated by solid-phase extraction on aminopropylsilica cartridges. CEs and triglycerides were eluted with chloroform. Phosphatidylcholine, which is the major plasma phospholipid, was eluted with chloroform:methanol (60:40, vol:vol). NEFAs were eluted by using chloroform:methanol:glacial acetic acid (100:2:2, vol:vol:vol). A second cartridge was used to separate CEs and triglycerides: CEs were eluted with hexane, and triglycerides were eluted with hexane:chloroform:ethyl acetate (100:5:5, vol:vol:vol). All lipids were dried under nitrogen and redissolved in toluene. Fatty acid methyl esters (FAMEs) were formed by incubation with methanol that contained 2% (vol:vol) H2SO4 at 50°C for 2 h. After allowing the tubes to cool, samples were neutralized with a solution of 0.25 mol KHCO3/L and 0.5 mol K2CO3/L. FAMEs were extracted into hexane, dried down, redissolved in a small volume of hexane, and separated by using gas chromatography. Gas chromatography was performed on a Hewlett-Packard 6890 gas chromatograph fitted with a BPX-70 column (30 m × 0.22 mm × 0.25 μm). The inlet temperature was 300°C. The oven temperature was initially 115°C and was maintained for 2 min after injection. The oven temperature was programmed to increase to 200°C at the rate of 10°C/min to hold at 200°C for 16 min and increase to 240°C at the rate of 60°C/min to hold at 240°C for 2 min. The total run time was just longer than 29 min. Helium was used as the carrier gas. FAMEs were detected by using a flame ionization detector held at a temperature of 300°C. The instrument was controlled by, and data collected, with HPChemStation software (Hewlett-Packard). FAMEs were identified by comparison of retention times with those of authentic standards run previously. Within-run CVs for analysis of EPA and DHA as methyl esters were 3% and 2%, respectively. Between-run CVs for analysis of EPA and DHA as methyl esters were 5% and 2.5%, respectively.