Therefore, considering these previous papers, aging may affect -6-desaturase activity, resulting in sex-based differences in fatty acid levels. Indeed, it is likely that serum levels of DGLA may decline with age, primarily because of reduced -6-desaturase activity [40]. In the present study, however, we analyzed samples from relatively young subjects (less than 37 years old) and could therefore not evaluate the effects of aging on fatty acid levels in the present cohort. Thus, to clarify whether there are differences in fatty acid levels in aging men and women, further studies in elderly subjects are required.