Calorie Restriction: Is it the route to health and longevity?
Published: March 10, 2017
Indications that calorie restriction (CR), which appears to delay the onset of age-related diseases, could extend mammalian average and maximum life spans began to emerge in 1935.
Since then numerous long term studies on animals such as mice and primates appear to support CR in the quest for longevity and delayed onset of age-related disease.
However, some studies do not support the claim that CR increases longevity and reduces the onset of age-related disease.
These contradictory results may be due to the differences in the diets that the study population is provided with.
The diets that study animals are fed are calorie restricted, but without malnutrition, implying that the animals received all the nutrients they required for good health. CR is more than just reducing the number of calories you eat.
It is important to note that in most studies CR refers to a 20-40% reduction of "ad libitum" or unrestricted consumption, with the proviso of maintaining adequate nutrient intake, which will differ among subjects to some degree.
Where adequate nutrient intake is obtained, CR may increase longevity, reduce morbidity and autoimmune disease, and reduce the age related onset of atherosclerosis, CVD, cancer, diabetes, renal disease, neurodegenerative diseases, and respiratory diseases.
People purposely restrict their calorie intake for the purpose of maintaining good health and a chance at increasing their life span.
However, currently there are few long term studies with human subjects to confirm or deny that CR (presumably without malnutrition) increases longevity and delays the onset of age-related disease.
Human CR studies range from 6 months to 2 years, but few extend beyond 6 years.
Age, weight and health of participants vary across studies and as with animal studies CR is based on ad libitum consumption and ranges between 20-25%.
Measurement of health benefits in human studies is limited to measurement of biomarkers which correlate with longevity. Studies indicate that CR may bring favourable changes in biomarkers related to...link to the full article to learn more.
Ricki J. Colman et al. (2009). Calorie restriction delays disease onset and mortality in Rhesus monkeys Science 325, 201 DOI: 10.1126/science.1173635
Whitney, E. & Rady Rolfes, S. (2005). Understanding Nutrition. Belmont, CA: Thomson Wadsworth