A 25-year longitudinal study on rhesus monkeys investigated the effects of a 30% caloric restriction (CR) diet on life span and health. Results showed that monkeys on a CR diet had fewer age-related diseases, with lower incidences of diabetes and better overall health compared to those on a normal diet. The study suggests that dietary restriction may enhance life expectancy and quality of life, although applying these findings to humans remains challenging.

1. Dietary restriction and aging in rhesus monkeysBy: J.J. Ramseya, R.J. Colmana, N.C. Binkleya,b, J.D. Christensena,T.A. Gresla, J.W. Kemnitza,c, R. WeindruchaCaloric Restriction Extends Life in Monkeys“Eat Less You Will Live Longer”Name: QossayTakrooriProfessor: Dr.JefferyRothweilerClass: Human Growth and Development

2. Questions being addressed:The study is about that relationship between diet and life span. In 1989, a longitudinal study was started to determine whether restricted diet is linked to the incensement of life expectancy in monkeys.

3. Theories: According to previous research, dietary restriction (DR) slows the aging process in laboratory mice and rats based on its ability to oppose the development of a broad spectrum of age-associated diseases and extend maximum lifespan. Moreover, the maximum life span of non-mammals is also increased by dietary restrictions.

4. Questions being asked: Life expectancy (the average life span) greatly increased during the 20th century in most countries, largely due to improved hygiene, nutrition, and health care. One possible approach to further increase human life span is “caloric restriction.” But does restricted diet have similar action in a primate species? Like Monkeys? Would RD enhance monkeys lives?

5. Purpose: Advance the development of the rhesus monkey as a model for the study of aging. Second, determine the influence of DR on the rate of aging in this primate species. Could the model “restricted diet” be applied on human in order to increase our life span, and improve the quality of our lives?The Methods Used:Operationalized: The study took around 25 years, which means it’s a longitudinal study. The initial study began in 1989 to investigate the effects of a 30% DR in 30 adult male rhesus monkeys. In 1994, an additional 30 females and 16 males were added to the study. The independent variable is diet or dietary restriction and the dependent variable is life span.

6. Preparation and operation: Environment:They had extensive visual and auditory contact with other monkeys. The animals were allowed continuous access to water, and the animal rooms were maintained at 21±26C with, 50±65% relative humidity. Artificial room light is automatically controlled to provide 12-h light and dark period. 2. Health Care Routine: The monkeys were test daily for health problems, injuries or any other complications. Among the 12 controls in Group 1, three animals became pre-diabetic versus none in the DR group. 3. Diet:All animals are fed a semi-purified diet which contains 15% lactalbumin, 10% corn oil and approximately 65% carbohydrate in the form of sucrose and corn starch The composition of the restricted and control diets is similar, but the restricted diet is supplemented with an additional 30% of the vitamin and mineral content to ensure that the groups, on average, consume a similar amount of micronutrients. Food intake is measured for each animal daily. All animals are fed in the morning and, at approximately 4 PM, any food remaining in each cage is removed and weighed. Intakes for individual animals are averaged weekly and summarized over a six-month period. The research team reduced the RD group by 30 percent over the past three months, but 30% percent diet reduction was too much for two of the animals because their body fat decreased to 3% followed by pale face, illness, and hair lost. The team decided in 1996 to increase the daily food intake to these animals in order to increase their body fat to 5% to maintain healthy body.

7. The Methods Used: Measurements and calculations: Most measurements are completed annually within a single, six-week assessment period. During Week 1, blood samples are collected for CBC (Complete Blood Count), chemistry panels, endocrine measurements and measurement of skeletal parameters. DXA measurements of body composition are also completed during Week 1. Urine collections are completed during Week 4 and indirect respiration calorimetrymeasurements of energy expenditure are completed in Week 5. Finally, during Week 6 of the assessment period, a frequently sampled intravenous glucose tolerance test(FSIGT) is done.

8. The Methods Used: