Effect of caloric restriction in non-obese humans on physiological, psychological and behavioral outcomes

Abstract

The focus of this review is on current research involving long-term calorie restriction (CR) and the resulting changes observed in physiological and behavioral outcomes in humans. Special emphasis will be given to the first completed clinical studies which are currently investigating the effects of controlled, high-quality energy-restricted diets on both biomarkers of longevity and on the development of chronic diseases related to age in humans. Prolonged CR has been shown to extend both the median and maximal lifespan in a variety of lower species such as yeast, worms, fish, rats, and mice. Mechanisms of this CR-mediated lifespan extension are not fully elucidated, but possibly involve significant alterations in energy metabolism, oxidative damage, insulin sensitivity, and functional changes in both the neuroendocrine and sympathetic nervous systems. In this brief report, we review some of the major physiological, psychological and behavioral changes after 6 month of CR in overweight otherwise healthy volunteers. Ongoing studies of prolonged CR in humans are now making it possible to analyze changes in "biomarkers of longevity" to unravel some of the mechanisms of its anti-aging phenomenon. With the incremental expansion of research endeavors in the area of energy or calorie restriction, data on the effects of CR in animal models and human subjects are becoming more accessible. Detailed analyses from controlled human trials involving long-term CR will allow investigators to link observed alterations from body composition down to changes in molecular pathways and gene expression, with their possible effects on the biomarkers of aging. Keywords calorie restriction; longevity; metabolic adaptation; quality of life; physical activity Why Caloric Restriction?Calorie restriction (CR), a dietary intervention that is low in calories but maintains proper nutrition, is the only intervention known to date that consistently decreases the biological rate of aging and increases both average and maximal lifespan. Since the first report of prolonged lifespan in rodents more than 70 years ago [1] similar observations have been reported across a wide range of species including yeast, worms, spiders, flies, fish, mice and rats [2]. While the effects of CR in longer lived species remains unknown, results reported thus far from 3 nonhuman primate colonies suggest that CR might have a similar effect in longer-lived species. While lifespan data remains inconclusive [3], CR monkeys display a substantially reduced age-

Psychological and metabolic stress: A recipe for accelerated cellular aging?

“…165,166 Caloric restriction appears to decrease metabolic rate, free radical generation, adiposity, and sympathetic activity and may reduce insulin and increase insulin sensitivity and DHEA-S levels. 167,168 It is thought that caloric restriction increases longevity in part through suppressing expression of sirtuins which then indirectly suppress fat mobilization (through suppressing PPAR-γ).…”

Angiotensin II blockade: how its molecular targets may signal to mitochondria and slow aging. Coincidences with calorie restriction and mTOR inhibition

“…Concluding, the available evidence endorses the idea that RAS-bl is among the interventions that may turn out to provide relief to the spreading issue of age-associated chronic disease. mechanistic target of rapamycin; vitamin D; caloric restriction; renin-angiotensin system EFFORTS AIMED AT DECIPHERING the mechanisms that underlie the aging process have unveiled three interventions that can increase survival and retard age-related diseases from lower organisms to mammals, i.e., caloric restriction (CR) (84,85,140,160,334), mechanistic target of rapamycin (mTOR; originally mammalian TOR) inhibition by rapamycin (173,196,281), and renin-angiotensin system blockade (RAS-bl) (20, 21, 26,63,253,284,354), although the latter has been less studied. In light of these findings, some intriguing questions come to mind: Do these interventions attenuate aging by interfering with common mechanisms?…”

Pengehadan Kalori, Fungsi Kognitif dan Penuaan: Peranan terhadap Sistem Biologi

“…Pakar perubatan mendapati berpuasa untuk jangka masa lama mampu mengurangkan emosi negatif pada pesakit yang mengalami kecelaruan makan (Moreno-Domínguez et al 2012). Tambahan pula, pengurangan berterusan kalori sebanyak 25% selama enam bulan boleh mengurangkan simptom depresi dan tidak menunjukkan kesan mood negatif yang ketara (Redman et al 2008). Kajian ke atas pesakit kronik dalam mengkaji kesan DPK selama dua minggu menunjukkan 80% kemajuan dalam mengurangkan depresi (Michalsen et al 2002).…”