Actividad Dietética最新文献

It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes. A vegetarian diet is defined as one that does not include meat (including fowl) or seafood, or products containing those foods. This article reviews the current data related to key nutrients for vegetarians including protein, n-3 fatty acids, iron, zinc, iodine, calcium, and vitamins D and B₁₂. A vegetarian diet can meet current recommendations for all of these nutrients. In some cases, supplements or fortified foods can provide useful amounts of important nutrients. An evidence-based review showed that vegetarian diets can be nutritionally adequate in pregnancy and result in positive maternal and infant health outcomes. The results of an evidencebased review showed that a vegetarian diet is associated with a lower risk of death from ischemic heart disease. Vegetarians also appear to have lower low-density lipoprotein cholesterol levels, lower blood pressure, and lower rates of hypertension and type 2 diabetes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates. Features of a vegetarian diet that may reduce risk of chronic disease include lower intakes of saturated fat and cholesterol and higher intakes of fruits, vegetables, whole grains, nuts, soy products, fiber, and phytochemicals. The variability of dietary practices among vegetarians makes individual assessment of dietary adequacy essential. In addition to assessing dietary adequacy, food and nutrition professionals can also play key roles in educating vegetarians about sources of specific nutrients, food purchase and preparation, and dietary modifications to meet their needs.

The dietetic activity carried out by the National Public Health School between 1932 and 1936 is analysed. The works published by the staff assigned to its Food Hygiene Laboratory have been used as the main source of information. In order to be able to prepare dietetic diets adapted to Spain's reality, it was intended to find out the chemical composition (water, starch, proteins, fat and mineral salts) of Spanish food items and their vitamin content. Following the recommendations and criteria of international organizations, a study was made on some of the products most frequently consumed, like olive oil, potatoes, fresh and tinned tomatoes, the strawberry, the garden strawberry, pears, plums and the prickly pear, as well as some tinned foods. The results obtained revealed the differences that existed with the data offered by foreign authors, and highlighted the higher amount of vitamin resources from products like Andalusian olive oil or the fresh Valencian tomato. These differences were attributed to the geoclimatic factor. In the case of stews (made with meat and chickpeas), the paella and the egg yoke, the changes that cooking processes could cause in the composition of the food products used were also studied.

In the face of the growing use of weight-losing strategies as an alternative to conventional methods, the Revision, Study and Positioning Group of the Spanish Association of Dieticians-Nutritionists (GREP-AEDN) has decided to analyse these methods and to provide information on the degree of efficacy, reliability and/ or risk involved in their use, specifically of the Food Sensitivity Tests. By means of this document, the GREP-AEDN advises against the use of these tests based on blood tests as diagnostic evidence for treating obesity, as well as for detecting possible allergies and/or food intolerances. This position is based on the fact that neither these tests nor the dietary treatments prescribed following their results have been validated by the scientific community. Furthermore, by revising the positions of the most important clinical societies in the field of allergology and immunology, as well as the scientific studies on the matter mentioned in this document, the GREP-AEDN considers that undergoing the dietary treatment resulting from the results of these tests (mainly characterised by the restriction of food items) not only means a waste of money, but it can entail health hazards.

Introduction

Foods enriched with ∼2 g of phytosterols have an obvious cholesterol-lowering effect. Although they are less known, the phytosterols of natural foods in the normal diet also help to reduce cholesterol. Taking phytosterols increases its plasma concentrations, especially those of sitosterol, which is the most abundant.

Objectives

To analyse the relation between the consumption of phytosterols from food, both in the normal diet and after taking supplemented foods, with phytosterolaemia and its relation with plasma lipids.

Design

The first work is a clinical study over a period of one year with 114 participants in the PREDIMED intervention study with a Mediterranean diet and, therefore, with food rich in phytosterols. The second work is a transversal observational study of 883 individuals from the Spanish group of the EPIC study. The third is a cross study of dietary intervention with a control group carried out on 56 subjects with hypercholesterolaemia who consumed milk supplemented with 2 g of phytosterols or a placebo.

Results and conclusions

The increase in the consumption of phytosterols, with their normal diet or with supplemented foods, is associated to high concentrations of sitosterol in plasma and which are inversely related with the concentrations of lathosterol, a cholesterol synthesis marker. In turn, the high counts of circulating sitosterol are associated with a better lipid profile and are markers of a healthy diet, with a high intake of vegetable foods, or else they reflect the adherence to the consumption of foods supplemented with phytosterols.