Publications (130) View all
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Dataset: 10 MARZETTI
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Article: Oxidative damage increases with reproductive energy expenditure and is reduced by food-supplementation.
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ABSTRACT: A central principle in life-history theory is that reproductive effort negatively affects survival. Costs of reproduction are thought to be physiologically based, but the underlying mechanisms remain poorly understood. Using female North American red squirrels (Tamiasciurus hudsonicus), we test the hypothesis that energetic investment in reproduction overwhelms investment in antioxidant protection, leading to oxidative damage. In support of this hypothesis we found that the highest levels of plasma protein oxidative damage in squirrels occurred during the energetically demanding period of lactation. Moreover, plasma protein oxidative damage was also elevated in squirrels that expended the most energy and had the lowest antioxidant protection. Finally, we found that squirrels that were food-supplemented during lactation and winter had increased antioxidant protection and reduced plasma protein oxidative damage providing the first experimental evidence in the wild that access to abundant resources can reduce this physiological cost.Evolution 05/2013; 67(5):1527-36. · 5.15 Impact Factor -
Article: Fasting and Caloric Restriction?
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ABSTRACT: Aging is associated with a host of biological changes that contribute to a progressive decline in cognitive and physical function, ultimately leading to a loss of independence, and increased risk of mortality. To date, prolonged caloric restriction (i.e., a reduction in caloric intake without malnutrition) is the only non-genetic intervention that has consistently been found to extend both mean and maximal life span across a variety of species. Most individuals have difficulty sustaining prolonged caloric restriction, which has led to a search for alternative approaches that can produce similar benefits as caloric restriction. A growing body of evidence indicates that fasting periods and intermittent fasting regimens in particular can trigger similar biological pathways as caloric restriction. For this reason, there is increasing scientific interest in further exploring the biological and metabolic effects of intermittent fasting periods, as well as whether long-term compliance may be improved by this type of dietary approach. This special will highlight the latest scientific findings related to the effects of both caloric restriction and intermittent fasting across various species including yeast, fruit flies, worms, rodents, primates, and humans. A specific emphasis is placed on translational research with findings from basic bench to bedside reviewed and practical clinical implications discussed.Experimental gerontology 04/2013; · 3.34 Impact Factor -
Article: Active muscle regeneration following eccentric contraction-induced injury is similar between healthy young and older adults.
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ABSTRACT: Repair of skeletal muscle after injury is a key aspect of maintaining proper musculoskeletal function. Studies have suggested that regenerative processes- including myogenesis and angiogenesis- are impaired during advanced age, but evidence from humans is limited. This study aimed to compare active muscle regeneration between healthy young and older adults. We evaluated changes in clinical, biochemical, and immunohistochemical indices of muscle regeneration at precisely two (T2) and seven (T3) days following acute muscle injury. Men and women aged 18-30 and ≥ 70 years, matched for gender and body mass index, performed 150 unilateral, eccentric contractions of the plantar flexors at 110% of 1RM. Data were analyzed using analysis of covariance adjusted for gender, habitual physical activity, and baseline level of the outcome. A total of 30 young (n=15, 22.5 ± 3.7 yr) and older (n=15, 75.8 ± 5.0 yr) adults completed the study. Following muscle injury, force production declined 16% and 14% in young and older adults, respectively, by T2 and in each group returned to 93% of baseline strength by T3. Despite modest differences in the pattern of response, post-injury changes in intramuscular concentrations of myogenic growth factors and number of myonuclear (DAPI+, Pax7+) cells were largely similar between groups. Likewise, post-injury changes in serum and intramuscular indices of inflammation (e.g. TNFα, MCP1) and angiogenesis (e.g. VEGF, KDR) did not significantly differ between groups. These findings suggest that declines in physical activity and increased co-morbidity may contribute to age-related impairments in active muscle regeneration rather than aging per se.Journal of Applied Physiology 03/2013; · 3.75 Impact Factor -
Article: Current nutritional recommendations and novel dietary strategies to manage sarcopenia.
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ABSTRACT: Sarcopenia, the loss of skeletal muscle mass and function that occurs with aging, is associated with increased risk for several adverse health outcomes, including frailty, disability, falls, loss of independent living, and mortality. At present, no pharmacological treatment exists that is able to definitely halt the progression of sarcopenia. Likewise, no pharmacological remedies are yet available to prevent the onset of age-related muscle wasting. The combination of nutritional interventions and physical exercise appears to be the most effective strategy presently available for the management of sarcopenia. The purposes of this review are to summarize the current knowledge on the role of nutrition as a countermeasure for sarcopenia, illustrate the mechanisms of action of relevant dietary agents on the aging muscle, and introduce novel nutritional strategies that may help preserve muscle mass and function into old age. Issues related to the identification of the optimal timing of nutritional interventions in the context of primary and secondary prevention are also discussed. Finally, the prospect of elaborating personalized dietary and physical exercise recommendations through the implementation of integrated, high-throughput analytic approaches is illustrated.The Journal of Frailty & Aging. 03/2013; 2(1):38-53.
