The biosure study: Influence of composition of diet and food consumption on longevity, degenerative diseases and neoplasia in wistar rats studied for up to 30 months post weaning

The 1200-rat Biosure Study had six interrelated aims: (1) To see whether dietary restriction (80% ad lib.) reduces the age-standardized incidence of fatal or potentially fatal neoplasia before the age of 30 months. (2) To see whether the beneficial effects of diet restriction can be achieved by (a) limiting the daily period of access to food to 6 hr, or by (b) limiting the energy value of the diet. (3) To see whether reduced calorie intake between weaning and age 4 months influences survival and/or incidence of non-neoplastic and neoplastic diseases. (4) To compare effects of food consumption, energy intake and protein intake on survival and disease. (5) To study the relationships between body weight at different ages with eventual survival and disease incidence. (6) To provide a database for studying relationships between various in-life measurements and eventual survival and disease incidence in individual animals. The different dietary regimens were associated with highly significant differences in longevity, in the incidence of degenerative diseases (particularly myocardial degeneration, chronic progressive nephropathy, polyarteritis, prostatitis and radiculoneuropathy), and in the age-standardized incidence of benign and malignant neoplasms of virtually all sites. The findings are considered in the light of earlier studies of the effects of dietary composition and calorie intake, and also in relation to the genetically determined characteristics of the Wistar strain of rats used in the study. Finally, the implications of the results of the study in relation to testing chemicals for chronic toxicity and carcinogenicity are discussed.