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Caloric Restriction: Difference between revisions
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==Effects in Humans== | ==Effects in Humans== | ||
The hormonal and metabolic effects of calorie restriction observed in experimental animals, such as lower body temperature, reduced metabolic rate, and decreased oxidative stress, have also been demonstrated in humans.{{pmid|18729811}}{{pmid|16595757}} Additionally, lower serum levels of basal insulin ("fasting insulin"), profibrotic proteins, various growth factors - such as PDGF and TGF-α - as well as cytokines like Tumor Necrosis Factor-α have been detected.{{pmid|15096581}}{{pmid|17389710}}{{pmid|17093155}}{{pmid|16732018}}{{pmid|16412867}} It is also established that long-term calorie restriction is an effective prevention against Type II Diabetes, high blood pressure, and Atherosclerosis, which together are the main causes of Morbidity, disabilities, and Mortality in humans.{{pmid|19262201}} | The hormonal and metabolic effects of calorie restriction observed in experimental animals, such as lower body temperature, reduced metabolic rate, and decreased [[Oxidative Stress|oxidative stress]], have also been demonstrated in humans.{{pmid|18729811}}{{pmid|16595757}} Additionally, lower serum levels of basal insulin ("fasting insulin"), profibrotic proteins, various growth factors - such as PDGF and TGF-α - as well as cytokines like Tumor Necrosis Factor-α have been detected.{{pmid|15096581}}{{pmid|17389710}}{{pmid|17093155}}{{pmid|16732018}}{{pmid|16412867}} It is also established that long-term calorie restriction is an effective prevention against Type II Diabetes, high blood pressure, and Atherosclerosis, which together are the main causes of Morbidity, disabilities, and Mortality in humans.{{pmid|19262201}} | ||
=== Longevity === | === Longevity === | ||
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=== Reduction of Oxidative Stress === | === Reduction of Oxidative Stress === | ||
There are indications that oxidative stress is reduced by decreased food intake, thereby delaying primary aging. Primary aging is the process in cells and organs that defines the maximum lifespan in the absence of diseases (inevitable aging). Secondary aging is determined by external factors such as diseases, environmental factors, lifestyle, and physical activity (avoidable aging).<ref name="Tostlebe2005">M. Tostlebe: [http://d-nb.info/978638670/34 ''Disproportionalität der Aktivitäten der mitochondrialen Atmungskettenkomplexe im Myokard und in der Skelettmuskulatur im Alter.''] Dissertation, Martin-Luther-Universität Halle-Wittenberg, 2005.</ref> Oxidative stress primarily occurs in the mitochondria, the powerhouses of the cells.{{pmid|19549533}}{{pmid|19634782}} In some mouse strains, the effect of calorie restriction can be partially induced by [[Resveratrol]].{{pmid|25824609}} In yeasts, the protein ''Rim15'', a glucose-inhibited protein kinase, acts as a sensor of nutrient concentrations as well as the initiator of Meiosis and is necessary for lifespan extension in yeasts.{{pmid|24706810}} However, a meta-analysis also reported that caloric restriction – contrary to previous results – does not lead to lifespan extension in yeasts, but the results in yeasts are partly based on methodological artifacts.{{pmid|25071164}} | There are indications that [[Oxidative Stress|oxidative stress]] is reduced by decreased food intake, thereby delaying primary aging. Primary aging is the process in cells and organs that defines the maximum lifespan in the absence of diseases (inevitable aging). Secondary aging is determined by external factors such as diseases, environmental factors, lifestyle, and physical activity (avoidable aging).<ref name="Tostlebe2005">M. Tostlebe: [http://d-nb.info/978638670/34 ''Disproportionalität der Aktivitäten der mitochondrialen Atmungskettenkomplexe im Myokard und in der Skelettmuskulatur im Alter.''] Dissertation, Martin-Luther-Universität Halle-Wittenberg, 2005.</ref> Oxidative stress primarily occurs in the mitochondria, the powerhouses of the cells.{{pmid|19549533}}{{pmid|19634782}} In some mouse strains, the effect of calorie restriction can be partially induced by [[Resveratrol]].{{pmid|25824609}} In yeasts, the protein ''Rim15'', a glucose-inhibited protein kinase, acts as a sensor of nutrient concentrations as well as the initiator of Meiosis and is necessary for lifespan extension in yeasts.{{pmid|24706810}} However, a meta-analysis also reported that caloric restriction – contrary to previous results – does not lead to lifespan extension in yeasts, but the results in yeasts are partly based on methodological artifacts.{{pmid|25071164}} | ||
===Hormesis=== | ===Hormesis=== | ||
According to a contrary hypothesis, oxidative stress from reactive oxygen species (ROS) is thought to positively stimulate cell metabolism (Hormesis), which may explain the health benefits of caloric restriction as well as Fasting, oxidative plant compounds in cabbage vegetables, and physical training.{{pmid|16242247}} | According to a contrary hypothesis, [[Oxidative Stress|oxidative stress]] from reactive oxygen species (ROS) is thought to positively stimulate cell metabolism (Hormesis), which may explain the health benefits of caloric restriction as well as Fasting, oxidative plant compounds in cabbage vegetables, and physical training.{{pmid|16242247}} | ||
In contrast to the free radical theory, it is assumed that an increased formation of reactive oxygen species in the mitochondria, associated with caloric restriction, causes an adaptive response that enhances stress resistance.{{pmid|20350594}} | In contrast to the free radical theory, it is assumed that an increased formation of reactive oxygen species in the mitochondria, associated with caloric restriction, causes an adaptive response that enhances stress resistance.{{pmid|20350594}} | ||