The Effects of Aging on Hair–More Than Just Amount 474 Changes in fiber properties with age also influence hair styles/ types, which in turn have an impact on hair breakage. More young adults keep their hair longer partly because it can grow coarser and longer at that age, due to the longer time span of anagen up to about age 45 for women. In most Western societies as women age beyond 45, their hair grows finer and cannot grow as long. Therefore, many of these women tend to move to shorter hair styles. For younger women with longer hair styles both wet and dry hair conditioning is important. However, damage to the ends can be very high because of the longer residence time (4 years for 20–24 inch tips) and more short segment breakage that occurs during dry combing and brushing. These actions provide more damage to the ends of the hair. Therefore, dry hair conditioning, especially at the tip ends, is very important to these younger women. For women in their fifties and beyond with shorter hair styles, hair breakage is more of a problem if their hair is curly. However, for all women with curly hair and shorter hair styles, mid-length combing forces are high especially for wet hair, and therefore wet hair conditioning is very important. Knowledge gaps for stretching, bending and torsional properties of hair with age: The effects of changes in hair curvature with age have not been examined with respect to age and hair breakage for Caucasians and Africans, and would provide important insight into the relationship between these properties as a function of aging. The effects of changes in ellipticity with age remain to be examined for African hair types. If ellipticity changes with age in African hair, subsequent analysis of the impact of changes in ellipticity on hair breakage for African type hair would provide additional insight into the impact of age-related changes in fiber properties on hair breakage. Hair Lipids and Age The two major sources of hair lipids are the hair matrix cells and the sebaceous glands that exist inside hair follicles. Masukawa et al.47 have provided some evidence that cholesterol, its esters,