Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Leanness and longevity

Leanness and longevity characteristics was conducted on 14 group A and 16 group R rats allowed to live out their natural life span. Total adipose tissue mass increased in both groups of rats until about 70 percent of life span after which it declined Leanness and markedly. As would be expected, the percent of total body mass as fat was less in the restricted fed animals. In group A rats, however, there was no correlation between adipose tissue mass and length of life and in group R rats fat mass was positively correlated longevity with longevity. Lean body mass was evaluated as a function of the percent of the total length of life of that rat rather than chronological age. It is a well recognised fact that on physiological and morphological Contrary to the generally held view average obese people do not live as characteristics. that a loss in lean body mass is a In the ad libitum-fed rats, food long as people of average weight. characteristic of ageing, lean body intake increased linearly until 18 Animal experiments have also shown mass increased for the first 70 to 75 that the relationship between weight months of age starting at about 11 g percent of the life span in both groups and longevity can be taken one stage per day and peaking at about 16 g per and was unchanged for most of the further: restriction on food intake to day. After 20 months of age, voluntary remainder and the life of the rat. levels well below normal desire will food intake declined but group R rats Declines were seen only at the very continued to receive 9.5 g of food per extend the life span of laboratory rats end of life where they were probably day for the remainder of their life beyond that of normal weight rats related to terminal disease rather than who have been given free access to span. Maximum body weight (about ageing per se. food. The biochemical mechanisms 525 g) was attained at 18 months of The special housing of the underlying the effects of food age in Group A and from 24 to 30 experimental animals enabled them to restriction are not well understood months of age in Group R (280 g). keep free from infectious diseases and and in any case they are complicated therefore to live longer. The by factors such as rat strain, effects The results experiments were able to show that on the animal of confinement, lack of food restriction prolongs immaturity The mean length of life was 701 ± exercise and exposure to other and it has been suggested that this in ten days for group A rats (n = 115) stresses encountered in the unnatural turn delays the onset of time- compared to 986 ± 25 days for the surroundings of the laboratory. triggered ageing processes. Other group R animals (n= k 115). Maximum Some fascinating work of Masaro workers have been able to show that length of life was 963 days in Group A and his colleagues in attempting to longevity is increased when adult compared with 1435 days in Group R. investigate several important mice and rats are kept on reduced Thus more than 60 percent of the biochemical and pathological food. From all this work, we can restricted fed animals survived the characteristics associated with the conclude that living on short longest lived ad libitum fed rat. extension of the life span by food commons could keep us more free The two major age-associated restriction was recently described in from disease and we would live lesions in male Fischer 344 rats are Nutrition Reviews1 the journal of the longer. chronic nephrosis and testicular American Nutrition Foundation. interstitial cell tumours. Food Reference restriction delayed the time of initial Animal experiments 1 Nutrition Reviews, vol. 40, no. 10, appearance and slowed the rate of October 1982 progression of the kidney lesions to In Dr Masaro's experiments a total their end stage of severity. Histo- of 531 male Fischer 344 weanling 28- pathological grading of group A rats day-old rats were delivered in a single shipment from the supplier. These dying spontaneously revealed that 95 rats were specific pathogen-free (SPF) percent had end stage or near end and for the duration of the study were stage kidney lesions whereas end stage severity was never detected in housed under 'barrier' conditions the restricted fed animals. The peak capable of maintaining SPF status. incidence of interstitial cell tumours During a 14-day adjustment period, all of these animals were fed ad libitum a was also delayed by restricted feeding semisynthetic diet of conventional (18 versus 24 months) and periarteritis composition and proportion. They was a much more frequent finding in group A as compared to group R rats. were then randomly selected either to Examination of the liver and heart continue on ad libitum intake (Group showed a similar trend of earlier A) or to be maintained on 60 percent of the mean ad libitum intake level appearance of such changes as bile (Group R). The group R diet contained duct hyperplasia, periductal fibrosis a vitamin supplement to assure equal and cystic spaces in the former and vitamin intake. Rats from each diet myocardial fibrosis and degeneration in the latter. No opinion was put group were then assigned to one of forward, however, as to the specific three separate studies: 1) a longevity cause of death of spontaneously dying study, 2) a longitudinal study of total fat mass and lean body mass and 3) a rats. cross-sectional study of various The longitudinal study of body mass 14 Nutrition and Food Science http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Nutrition & Food Science Emerald Publishing

Leanness and longevity

Nutrition & Food Science , Volume 83 (3): 1 – Mar 1, 1983

Loading next page...
 
/lp/emerald-publishing/leanness-and-longevity-mJqYR00nsm

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Emerald Publishing
Copyright
Copyright © Emerald Group Publishing Limited
ISSN
0034-6659
DOI
10.1108/eb058950
Publisher site
See Article on Publisher Site

Abstract

characteristics was conducted on 14 group A and 16 group R rats allowed to live out their natural life span. Total adipose tissue mass increased in both groups of rats until about 70 percent of life span after which it declined Leanness and markedly. As would be expected, the percent of total body mass as fat was less in the restricted fed animals. In group A rats, however, there was no correlation between adipose tissue mass and length of life and in group R rats fat mass was positively correlated longevity with longevity. Lean body mass was evaluated as a function of the percent of the total length of life of that rat rather than chronological age. It is a well recognised fact that on physiological and morphological Contrary to the generally held view average obese people do not live as characteristics. that a loss in lean body mass is a In the ad libitum-fed rats, food long as people of average weight. characteristic of ageing, lean body intake increased linearly until 18 Animal experiments have also shown mass increased for the first 70 to 75 that the relationship between weight months of age starting at about 11 g percent of the life span in both groups and longevity can be taken one stage per day and peaking at about 16 g per and was unchanged for most of the further: restriction on food intake to day. After 20 months of age, voluntary remainder and the life of the rat. levels well below normal desire will food intake declined but group R rats Declines were seen only at the very continued to receive 9.5 g of food per extend the life span of laboratory rats end of life where they were probably day for the remainder of their life beyond that of normal weight rats related to terminal disease rather than who have been given free access to span. Maximum body weight (about ageing per se. food. The biochemical mechanisms 525 g) was attained at 18 months of The special housing of the underlying the effects of food age in Group A and from 24 to 30 experimental animals enabled them to restriction are not well understood months of age in Group R (280 g). keep free from infectious diseases and and in any case they are complicated therefore to live longer. The by factors such as rat strain, effects The results experiments were able to show that on the animal of confinement, lack of food restriction prolongs immaturity The mean length of life was 701 ± exercise and exposure to other and it has been suggested that this in ten days for group A rats (n = 115) stresses encountered in the unnatural turn delays the onset of time- compared to 986 ± 25 days for the surroundings of the laboratory. triggered ageing processes. Other group R animals (n= k 115). Maximum Some fascinating work of Masaro workers have been able to show that length of life was 963 days in Group A and his colleagues in attempting to longevity is increased when adult compared with 1435 days in Group R. investigate several important mice and rats are kept on reduced Thus more than 60 percent of the biochemical and pathological food. From all this work, we can restricted fed animals survived the characteristics associated with the conclude that living on short longest lived ad libitum fed rat. extension of the life span by food commons could keep us more free The two major age-associated restriction was recently described in from disease and we would live lesions in male Fischer 344 rats are Nutrition Reviews1 the journal of the longer. chronic nephrosis and testicular American Nutrition Foundation. interstitial cell tumours. Food Reference restriction delayed the time of initial Animal experiments 1 Nutrition Reviews, vol. 40, no. 10, appearance and slowed the rate of October 1982 progression of the kidney lesions to In Dr Masaro's experiments a total their end stage of severity. Histo- of 531 male Fischer 344 weanling 28- pathological grading of group A rats day-old rats were delivered in a single shipment from the supplier. These dying spontaneously revealed that 95 rats were specific pathogen-free (SPF) percent had end stage or near end and for the duration of the study were stage kidney lesions whereas end stage severity was never detected in housed under 'barrier' conditions the restricted fed animals. The peak capable of maintaining SPF status. incidence of interstitial cell tumours During a 14-day adjustment period, all of these animals were fed ad libitum a was also delayed by restricted feeding semisynthetic diet of conventional (18 versus 24 months) and periarteritis composition and proportion. They was a much more frequent finding in group A as compared to group R rats. were then randomly selected either to Examination of the liver and heart continue on ad libitum intake (Group showed a similar trend of earlier A) or to be maintained on 60 percent of the mean ad libitum intake level appearance of such changes as bile (Group R). The group R diet contained duct hyperplasia, periductal fibrosis a vitamin supplement to assure equal and cystic spaces in the former and vitamin intake. Rats from each diet myocardial fibrosis and degeneration in the latter. No opinion was put group were then assigned to one of forward, however, as to the specific three separate studies: 1) a longevity cause of death of spontaneously dying study, 2) a longitudinal study of total fat mass and lean body mass and 3) a rats. cross-sectional study of various The longitudinal study of body mass 14 Nutrition and Food Science

Journal

Nutrition & Food ScienceEmerald Publishing

Published: Mar 1, 1983

There are no references for this article.