title: Housing density does not influence the longevity effect of calorie restriction.
abstract: This study examined the effect of housing density on the longevity-extending and disease-delaying actions of calorie restriction (CR). Singly or multiply housed (four per cage) mice were either fed ad libitum (AL) or were on CR beginning at 2 months. All CR mice were fed 40% less food than were multiply housed AL mice. CR increased median longevity by 19%, and housing density had no effect on this increase. CR also reduced neoplastic lesions in both housing groups, but lymphoma, the most common neoplasm, was reduced more in singly than in multiply housed mice. Singly housed AL mice ate 40% more food than did multiply housed AL mice, but weighed the same and lived as long as multiply housed AL mice. These results indicate that CR can extend life span as effectively in multiply as in singly housed mice, even though housing density can differentially affect the cancer-reducing effect of CR.
authors.affiliation: Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care Systems, San Antonio, TX, USA.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ikeno
authors.forename: Gene B
authors.initials: GB
authors.lastname: Hubbard
authors.forename: Shuko
authors.initials: S
authors.lastname: Lee
authors.forename: Arlan
authors.initials: A
authors.lastname: Richardson
authors.forename: Randy
authors.initials: R
authors.lastname: Strong
authors.forename: Vivian
authors.initials: V
authors.lastname: Diaz
authors.forename: James F
authors.initials: JF
authors.lastname: Nelson
mesh_terms: D000818:Animals; D031204:Caloric Restriction; D003441:Crowding; D008136:Longevity; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL