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Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake
(caloric restriction|hippocampus|insulin|beta -hydroxybutyrate| ketosis)
R. Michael Anson*,dagger , Zhihong Guo*, Rafael de Cabo, Titilola Iyun, Michelle Rios, Adrienne Hagepanos, Donald K. Ingram, Mark A. LaneDagger , and Mark P. Mattson§
Laboratory of Neurosciences, Gerontology Research Center, National Institute on Aging, 5600 Nathan Shock Drive, Baltimore, MD 21224
Edited by Anthony Cerami, The Kenneth S. Warren Institute, Kitchawan, NY, and approved March 25, 2003 (received for review October 18, 2002)
ציטוט:
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Dietary restriction has been shown to have several health benefits including increased insulin sensitivity, stress resistance, reduced morbidity, and increased life span. The mechanism remains unknown, but the need for a long-term reduction in caloric intake to achieve these benefits has been assumed. We report that when C57BL/6 mice are maintained on an intermittent fasting (alternate-day fasting) dietary-restriction regimen their overall food intake is not decreased and their body weight is maintained. Nevertheless, intermittent fasting resulted in beneficial effects that met or exceeded those of caloric restriction including reduced serum glucose and insulin levels and increased resistance of neurons in the brain to excitotoxic stress. Intermittent fasting therefore has beneficial effects on glucose regulation and neuronal resistance to injury in these mice that are independent of caloric intake.
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Intermittent Food Deprivation Improves Cardiovascular and Neuroendocrine Responses to Stress in Rats
Ruiqian Wan, Simonetta Camandola and Mark P. Mattson1
Laboratory of Neurosciences, National Institute on Aging Gerontology Research Center, Baltimore, MD 21224
1To whom correspondence should be addressed. E-mail:
mattsonm@grc.nia.nih.gov.
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ציטוט:
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Stressful events may trigger disease processes in many different organ systems, with the cardiovascular system being particularly vulnerable. Five-mo-old male rats had ad libitum (AL) access to food or were deprived of food every other day [intermittent food deprivation (IF)] for 6 mo, during which time their heart rate (HR), blood pressure (BP), physical activity and body temperature were measured by radiotelemetry under nonstress and stress (immobilization or cold-water swim) conditions. IF rats had significantly lower basal HR and BP, and significantly lower increases in HR and BP after exposures to the immobilization and swim stressors. Basal levels of adrenocorticotropic hormone (ACTH) and corticosterone were greater in the IF rats. However, in contrast to large stress-induced increases in ACTH, corticosterone and epinephrine levels in AL rats, increases in these hormones in response to repeated immobilization stress sessions were reduced or absent in IF rats. Nevertheless, the IF rats exhibited robust hypothalamic/pituitary and sympathetic neuroendocrine responses to a different stress (swim). The IF treatment improved glucose metabolism, as indicated by lower basal levels of circulating glucose and insulin, but with maintenance of glucose and insulin responses to stress. We concluded that improvements in cardiovascular risk factors and cardiovascular and neuroendocrine stress adaptation occur in response to IF.
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