Progress in food & nutrition science最新文献

Interest in the use of alternative dietary lipids to prevent or control human disease has gained scientific support from numerous studies which have uncovered beneficial effects of increased amounts of polyunsaturated fish and plant oils upon such diverse disease processes as atherosclerosis and coronary heart disease, rheumatoid arthritis, post-operative and post-traumatic recovery, and sepsis. The immunologic processes which underly these pathologic states, and the possible ways in which dietary lipids may influence immunologic function are areas of active research. This review aims to summarize the current views of understanding how immune-mediated processes and inflammatory states may be altered by the content and types of lipids in the diet.

Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by a retrovirus infection, representing the end point in a progressive sequence of immunosuppressive changes. The literature is briefly summarized as to immunological, nutritional and other pathological modifications caused by AIDS, and properties of immunoenhancing, anti-oxidant and undernutrition-restoration of vitamin E supplementation. All these abnormalities in AIDS are similar to those that are stimulated or restored by intake of high doses of vitamin E. The drawbacks of pharmacological therapy like zidovudine (AZT), e.g. deleterious toxic side effects, inability to improve the immune dysfunctions and undernutrition initiated by the retrovirus infection, and finding of AZT-resistant HIV strains, necessitate new strategies for the clinical trials of novel therapies to treat AIDS with the existing medical therapies. Low toxicity nutritional agents with immunoenhancing and antioxidant activities like vitamin E may help to normalize retrovirus-induced immune dysfunctions, undernutrition and other pathological symptoms, thereby retarding the progression of the disease to AIDS. To address this vitamin E therapeutic role in HIV-positive individuals, This paper presents a review of vitamin E-related therapeutic roles in animals and humans, thereby showing why vitamin E supplementation could be used as a useful therapeutic agent in human AIDS therapy. Since there is a paucity of information available regarding the nutritional therapy in AIDS individuals, our purpose is to provide evidence from animal models or humans of the potential therapeutic role of vitamin E supplementation in the treatment of AIDS individuals.

Bone formation and bone remodeling are complicated processes regulated by systemic hormones and paracrine factors which regulate calcium and phosphate fluxes and cellular differentiation. The many actions of vitamin D reinforces its importance in the process of growth, maturation and aging of bone. An understanding of these important regulators of bone metabolism is important to understanding the clinical disorders as they are related to alterations in vitamin D metabolism and metabolic bone disease. Specific disorders of vitamin D metabolism can be related to clinical disease states of aging, altered lifestyles, gastrointestinal, renal and hepatic disease. A classification of altered vitamin D metabolism as related to its clinical states is presented. The scope of vitamin D deficiency from childhood rickets to adult osteomalacia and osteoporosis is presented, Intermediate syndromes of high turnover osteoporosis, subclinical vitamin D-deficiency states, role of vitamin D analogues in treating type I and type II osteoporosis is discussed. Treatment guidelines for managing this scope of clinical vitamin D disorders are provided.

A large number of responses to dietary boron occur when the boron content of the diet is manipulated. Numerous studies suggest that boron interacts with other nutrients and plays a regulatory role in the metabolism of minerals, such as calcium, and subsequently bone metabolism. Although the mechanism of action has not been defined, it may be mediated by increasing the concentration of steroid hormones such as testosterone and beta-oestradiol. Boron is obtained from a diet rich in fruits, vegetables, nuts and legumes. The daily intake has been estimated to range from 0.3-41 mg per day. The wide range is due to the variation of the analytical methods used and differences in the soil content of boron. Based on a limited number of studies, increasing dietary boron results in increases in the boron concentration of all tissues. Large amounts of boron are well tolerated while consistent signs of deficiency include depressed growth and a reduction in some blood indices, particularly steroid hormone concentrations. Via its effect on steroid hormones and interaction with mineral metabolism, boron may be involved in a number of clinical conditions such as arthritis. Further research is required before boron is accepted as an essential nutrient for humans.

This review has a focus on the distribution and function of iron in human brain and appropriate animal models. Data are presented on the consequences of abnormalities of iron status with regard to neural development, neurotransmitter metabolism, and cognition.

Significant changes in body composition that have important health related effects are believed to occur in the elderly. Knowledge of these changes is important for diagnoses, prognoses, and treatment of health problems. Many health problems in the elderly could be prevented or alleviated by nutritional modulation, but better understanding of the nature, extent, and underlying physiology of body compositional changes is needed for such interventions to be successful. There are currently few data for body composition in the elderly, especially for those greater than 75 y in age, partly because conventional methods of assessing body composition are difficult to apply for technical and conceptual reasons. As a result, little is known regarding the relationships of body composition to nutritional, functional or health status in non-hospitalized, free-living elderly persons. Knowledge of the "natural history" of body compositional changes and their relationships to other nutritional and health factors could lead to new insights on prevention and treatment, the reduction of morbidity and extension of the quality of life of older persons.

Progress in our understanding of the pathophysiology of diabetes mellitus has been made possible because of the availability of animal analogs of the various human diseases. Diabetes mellitus can be mild, moderate or severe depending on the genetic error that is responsible for the disease. Present estimates of errors that result in diabetes range from 20 to 100. Because similar errors have been found in spontaneously diabetic animals scientists have been able to identify the sequence of metabolic events and subsequent tissue change in many of these phenotypes. Studies of the efficacy of various drugs, diets and lifestyle choices on disease development and management thus were made possible.

Loss of functional integrity of the vascular endothelium may be one of the initiating events in the etiology of atherosclerosis. Endothelial cells interact with blood components and the abluminal tissues, thus playing an active role in many aspects of vascular functions, such as permeability and vessel tone regulation. Endothelial cells constantly are exposed to nutrients which can modulate enzymes, receptors, transport molecules and various vasoactive mediators, resulting in significant functional changes of the endothelium and the underlying tissues. Nutrition may play an important role in the atherosclerotic disease process. There is evidence that certain vitamins and minerals prevent some metabolic and physiological perturbations of the vascular endothelium. This review focuses on selected lipids which cause endothelial cell injury or dysfunction and on nutrients which may exhibit antiatherogenic properties by being able to function as antioxidants or membrane stabilizers.

Previous experience throughout the world has suggested that certain populations have a genetic predisposition to the development of non-insulin dependent diabetes mellitus (NIDDM) in response to a changing environment. In particular, Native American admixture presents a genetic risk for NIDDM and modernization represents an environmental change which amplifies the risk. This review discusses these factors with respect to the situation in Mexico, where a significant portion of the population is Native American and industrialization is producing rapid environmental changes. Perhaps, with foresight, the epidemic of NIDDM which has struck Native Americans in the United States and indigenous groups in the South Pacific may be averted in Mexico. Specific aspects of the traditional Mexican lifestyle which could be retained to protect against NIDDM are presented.