BACKGROUND: We review studies showing that CR acts rapidly, even in late adulthood, to extend health- and lifespan in mice. These rapid physiological effects are closely linked to patterns of gene expression in liver and heart. Non-human primate and human studies suggest that the signal transduction pathways responsible for the lifespan and health effects of caloric restriction (CR) may also be involved in human longevity. Thus, pharmaceuticals capable of mimicking the effects of CR (and other methods of lifespan extension) may have application to human health.
Calorie restriction (CR) is a non-genetic manipulation that reliably results in extended lifespan of several species ranging from yeast to dogs. The lifespan extension effect of CR has been strongly associated with an increased level and activation of the silent information regulator 2 (Sir2) histone deacetylase and its mammalian ortholog Sirt1. This association led to the search for potential Sirt1-activating, life-extending molecules. This review briefly outlines the experimental findings on resveratrol and other dietary activators of Sirt1.
Vitamin E refers to a family of several compounds that possess a similar chemical structure comprising a chromanol ring with a 16-carbon side chain. The degree of saturation of the side chain, and positions and nature of methyl groups designate the compounds as tocopherols or tocotrienols. Vitamin E compounds have antioxidant properties due to a hydroxyl group on the chromanol ring. Recently, it has been suggested that vitamin E may also regulate signal transduction and gene expression.
Longevity can be explained by the free radical theory of aging, and caloric restriction (CR) studies showed that CR-induced lifespan extension is associated with the prevention of a decrease in oxidative stress. Non-enzymatic lipophilic antioxidants may play a pivotal role in our aging process, and are reflected in our dietary lifestyle and dietary supplementation. Their significance lies in their general good absorption and slow excretion within our body.
Aging degrades motivation, cognition, sensory modalities and physical capacities, essentially dimming zestful living. Bradykinesis (declining physical movement) is a highly reliable biomarker of aging and mortality risk. Mice fed a complex dietary supplement (DSP) designed to ameliorate five mechanisms associated with aging showed no loss of total daily locomotion compared with >50% decrement in old untreated mice.
Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases.
BACKGROUND: Zinc deficiency due to poor nutrition or genetic mutations in zinc transporters is a global health problem and approaches to providing effective dietary zinc supplementation while avoiding potential toxic side effects are needed. METHODS/PRINCIPAL FINDINGS: Conditional knockout of the intestinal zinc transporter Zip4 (Slc39a4) in mice creates a model of the lethal human genetic disease acrodermatitis enteropathica (AE).
The impact of diet and specific food groups on aging and age-associated degenerative diseases has been widely recognized in recent years. The modern concept of the free radical theory of aging takes as its basis a shift in the antioxidant/prooxidant balance that leads to increased oxidative stress, dysregulation of cellular function, and aging. In the context of this theory, antioxidants can influence the primary "intrinsic" aging process as well as several secondary age-associated pathological processes.
The current adult guidelines for a healthy diet make no distinctions between adults aged 25-50 y and those aged 51 y and over. The question is whether dietary guidelines ought to be stratified by age, in recognition of the dietary and nutrient needs of the growing population of elderly adults. There are limited data on nutrient requirements of older adults. Aging is accompanied by a variety of physiological, psychological, economic and social changes that may adversely affect nutritional status.
The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
During recent decades, the concept of health promotion has become a legitimate part of health care because of the aging of the postwar baby boom generation. As this population ages, the potential strain on health care systems will increase because the greatest use of health care services occurs during the last years of life. In older adults there are many correctable health factors that can be assessed through screening protocols.