A CURA DEL DOTT. GUARDO S. RAUL ONLUS (D.Lgs. 460/97) 1 Nutrition and Women's Health By Dr. Raul Guardo Salinas Proteins are essential for life! Protein comes from the greek word "protos" meaning "first element". Proteins are essential for growth and repair, to maintain functionality and structure of the body and of all living cells. Hormones, like insulin, check blood sugar levels; enzymes such as amylase, lipase and protease, are crucial in the digestion of food; antibodies help us fight infection while muscle proteins make contraction possible, etc.. So proteins are absolutely essential for life! Amino acids; the bricks Proteins consist of amino acids (the building blocks) linked together. An average protein may contain 300 or more amino acids. Each protein has a specific number of amino acids, arranged in a precise sequence. The shape of the molecule is important because it often determines the function of the protein. There are about 20 amino acids commonly found in plants and animals. The protein cycle After we eat, proteins are broken down through digestion into amino acids. The amino acids are then absorbed and used to build other proteins in the body. An adequate daily intake of protein and energy ensures the continuation of this cycle. Dietary sources Proteins are found in different types of food. Animal protein sources, such as meat, poultry, fish, eggs, milk, cheese and yogurt, provide proteins of high biological value. Vegetables protein sources, such as legumes, cereals, nuts, seeds and vegetables provide a low biological value in proteins. However, since the limiting amino acid tends to be different in a variety of plant proteins, a combination of proteins from different vegetable sources in a meal (ex. vegetables or Via Tosco Romagnola, 15 – 56012 FORNACETTE (PI) – Tel. 0587/423101 – Fax 0587/423133 Cod. Fisc., Part. IVA e Registro Imprese 01289270504 – Albo Cooperative A115410 e-mail: [email protected] sito web: www.agapesociale.it ONLUS (D.Lgs. 460/97) legumes with cereals), often results in a blend greater biological value. These combinations are 2 generally found in recipes of traditional dishes from different continents (ex. beans with rice, pasta or cassava bread with chickpeas, lentils and potatoes, etc.). Omnivorous diets (containing foods derived from animals and plants) in the developed world provide adequate amounts of protein. However, subgroups of the population who avoid eating animal based foods may have difficulty in achieving an adequate protein intake. General Recommendations In order to maintain a balanced protein level (protein accretion) required for sufficient growth and repair of body tissues, 10-15% of our calorie intake should come from protein. Carbohydrates (carbs) Whenspeaking of carbohydrates, we refer primarily to starch or foods like pasta, bread, rice, potatoes, which are also considered to be the main opponents of fitness and are, therefore, the first to be drastically reduced (even eliminated), when undergoing a self-prescribed weight -loss diet. From a chemical point of view, carbohydrates can be divided into: monosaccaride, or carbohydrates consisting of a single molecule including the presence of glucose and fructose, disaccharides, which consist of two carbohydrate molecules, including maltose ( formed from two glucose molecules, mainly present in barley and corn), sucrose (made up of one molecule of glucose, one of fructose and lactose, such as is found in sugar cane and sweeteners in general) and lactose (formed by one molecule of glucose and one galactose, as in milk sugar); polysaccharides, or carbohydrates formed of many molecules, contain starch cultivated from corn seeds, legumes and potatoes, as well as cellulose which is one of the fundamental components of the structure of plant cells. In general, carbohydrates are considered an important and fundamental source of energy for all living organisms. From this statement we can conclude that it is vital that man maintain a regular daily intake of carbohydrates, and the common belief of carbohydrates as a hinderance to fitness is certainly reduced. In fact, the right amount of carbohydrates may even be necessary to defeat excessive fat . The first point to make is that all carbohydrates, including the disaccharides and polysaccharides, are transformed during the metabolic process in mono, and one each of these molecules play then goes to a precise function. Carbohydrates, besides being an immediate source of energy are essential to our body to digest proteins and lipids to destroy. The reason why carbohydrates are often viewed with fear is that, if taken in quantities exaggerated, high blood sugar can stimulate insulin accelerates the formation of new fat cells and creating a sense of weariness and fatigue. Rich foods complex carbohydrates like pasta, bread and rice or disaccharides such as sugar and milk, or the many vegetables that contain simple carbohydrates, should therefore not be excluded from a healthy diet, even if it has as goal weight loss, but are simply made in such quantities that carbohydrates can raise their energy, Via Tosco Romagnola, 15 – 56012 FORNACETTE (PI) – Tel. 0587/423101 – Fax 0587/423133 Cod. Fisc., Part. IVA e Registro Imprese 01289270504 – Albo Cooperative A115410 e-mail: [email protected] sito web: www.agapesociale.it ONLUS (D.Lgs. 460/97) burn fat. 3 In conclusion then simply pay a minimum of attention to the quality and quantity of carbohydrates in food. Vitamins Are among the micronutrients that should be taken daily because they cannot be synthesized in the body. According to their solubility, they are classified as: soluble vitamins, (meaning soluble in fats): these include vitamins A, D, E and K; water-soluble vitamin: are vitamins C, B1, B2, B5, B6, PP, B12, Bc and H. Discovery The discovery of vitamins began with the observation that a diet consisting of carbohydrates, lipids, proteins ad mineral salts was not enough to ensure proper development and growth of an organism. Certain vital growth factors had to be added. The necessary amount of vitamins varies from one species to another. For example, humans are the only species that require Vitamin C in their diet. Classification Vitamins come in a variety of chemical structure. At present, they are divided into two groups: Water soluble vitamins (vitamins B and C) and Fat soluble vitamins (vitamins A, E, D and K). Via Tosco Romagnola, 15 – 56012 FORNACETTE (PI) – Tel. 0587/423101 – Fax 0587/423133 Cod. Fisc., Part. IVA e Registro Imprese 01289270504 – Albo Cooperative A115410 e-mail: [email protected] sito web: www.agapesociale.it ONLUS (D.Lgs. 460/97) 4 Use Vitamins should be taken regularly over a period of time. Only some have a specific required daily amount (vitamins A, D, PP, folic acid, B1, B2, B6 and B12). Vitamin requirements depend on the physiological and/or pathological state of the individual. Age, sex and whether the individual is pregnant or nursing. Vitamin deficiencies and the diseases that occur from them, such as pellagra, beriberi and rickets, are a major problem in developing countries. These are caused either by malnutrition or the fault of unhealthy food taboos that exist in these countries. Developed countries must deal with hypervitaminosis caused by an imbalanced and excessive diet that lacks certain vital nutrients. A restricted or vegetarian diet often does not supply the body with the vitamins that it needs, while high-calorie diets often lead to an overdose in other substances that may wash out the fat and water soluble vitamins. Even some medications or the excessive use of industrial products may interfere with the absorption or activity of some vitamins. Some methods of food preparation and cooking may result in the deterioration of vitamin nutrients (although susceptibility to physical or chemical agents is the same for all vitamins). But even these procedures will not diminish the concentration of a vitamin below 50%. It is difficult to accumulate water- soluble vitamins in the body because they are quickly eliminated along with urine while the fat-soluble vitamins are stored as tissue and used up at a slower rate. This allows the possibility of toxicity and also explains why it is wise to never exceed the recommend dosage. It is also known that, if the recommended dosage is exceeded by over 10 times, it may cause additional negative pharmacological effects. Enzymes Enzymes are proteins that catalyze (increase the rate of) chemical reactions. The molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, called the products. Enzymes work by lowering the activation energy for a reaction, thus dramatically increasing the rate and temperature of the reaction. Enzymes are not consumed by the reactions they catalyze, nor do they alter the equilibrium of these reactions. Via Tosco Romagnola, 15 – 56012 FORNACETTE (PI) – Tel. 0587/423101 – Fax 0587/423133 Cod. Fisc., Part. IVA e Registro Imprese 01289270504 – Albo Cooperative A115410 e-mail: [email protected] sito web: www.agapesociale.it ONLUS (D.Lgs. 460/97) 5 They are produced by living cells. Some substrates are homogeneous (consisting of only one cell group) while others are compound (made of groups linked by the protein protease). Each enzyme acts on a single substrate and partakes in only one step of the reaction. Metabolic or complex reactions require the coordinated activity of several types of enzymes. In fact, every individual contains more than 2000 different enzymes. Through these reactions we can recognize six macro-groups of enzymes: oxidoreductases, transferases, hydrolysis, lyase, ligase, and isomerase. Raw and unpasturized foods are much easier to digest because they already contain the necessary enzymes in them for the digestive process. Our stomach is made up of differnent functional areas: the upper area of the stomach, where the ingested food rests temporarily without being attacked by acids or enzymes, is where the food begins a process of auto-digestion of itself.