InterventionTryptophan Restriction
Alternate Name
OrganismRattus norvegicus
Aging PhenotypeLife-span extension
Allele TypeN/A
DescriptionFemale Long-Evans rats fed a diet containing 30-40% the amount of tryptophan as control animals results in an increased life-span (Ooka et al., 1988).
Gene FunctionTryptophan is an essential amino acid.
Other PhenotypesMortality among low-tryptophan-fed rats was greater in the juvenile period, but substantially less than controls at late ages. Histological biomarkers of aging were also delayed after tryptophan restriction in some organs (liver, heart, uterus, ovary, adrenal and spleen) but not in others (kidney, lung, aorta). Brain serotonin levels were low in tryptophan-deficient rats but showed remarkable capacity for rehabilitation (Ooka et al., 1988).
Tryptophan restriction in mice also extends life-span (De Marte and Enesco, 1986) as does methionine restriction in rats (Orentreich et al., 1993).
Primary ReferenceOoka, H., Segall, P. E., and Timiras, P. S. (1988). Histology and survival in age-delayed low-tryptophan-fed rats. Mech Ageing Dev 43, 79-98. [Abstract]
Other ReferencesOrentreich, N., Matias, J. R., DeFelice, A., and Zimmerman, J. A. (1993). Low methionine ingestion by rats extends life span. J Nutr 123, 269-74 [Abstract]
De Marte, M. L., and Enesco, H. E. (1986). Influence of low tryptophan diet on survival and organ growth in mice. Mech Ageing Dev 36, 161-71. [Abstract]
Relevant Links
Keywordscalorie restriction, caloric, diet, nutrition, amino acid, protein