Knowledge of nutrients and their functions in the body is necessary to understand the importance of good nutrition;
the six groups of nutrients - carbohydrates, fats, proteins, vitamins, minerals and water - are present in the foods we eat and contain the chemicals that work in one or more ways in our bodies: they supply the body with energy and heat, as well as substances for tissue growth and repair and help regulate processes. Each nutrient has its own specific functions for the body, but none act independently of the others. Some vitamins and minerals have particular links, but all are linked directly or indirectly. All nutrients are vital and there is no one more important than another. All of them must be present in the diet in different quantities for the body to carry out its basic metabolism. When the necessary quantities are not taken, a deficiency is created which leads to an imbalance. The body then becomes vulnerable to various diseases and ailments. Although everyone needs the same nutrients, each individual is different in genetic and physiological conformation. For this reason, there are differences in the nutritional needs of each person.
The typical individual shows an average need for many of the essential nutrients: however, there are some people who may have unusual nutritional needs due to genetic causes or absorption problems. Other factors that alter dosages are age, physical conformation, activity level, lifestyle, sex and type of diet.
All natural vitamins are organic compounds found only in living things, such as animals and plants. Up to now less than twenty substances have been discovered which are considered active as vitamins in the human organism; however, new substances are always discovered that work side by side with vitamins.These include carotenoids, polyphenols and phytochemicals. These substances (described later in this chapter) together with the vitamins and minerals present in various quantities in specific foods, are absolutely necessary for good growth, for the maintenance of health and for the prevention of disease.
With a few exceptions, the body cannot synthesize vitamins; they must be provided by the diet or food supplements, and the importance of a diet based on wholesome and wholesome foods cannot be emphasized enough. Science seeks to isolate these substances from foods that heal, keep healthy, and prevent disease, but their optimal combination is found only in the foods we consume. For example, some studies carried out on beta-carotene supplements have shown that the carotenoid responsible for the antioxidant action is not just one but a combination of various carotenoids. If we consume the food that contains them all, we avoid having to guess. However, it has recently been shown that those who take vitamin supplements live longer and that they are essential for the prevention and treatment of diseases.
Taking vitamin and mineral supplements is desirable because, despite the growing awareness of the importance of diet, many people are not eating enough balanced meals consistently.
Older people are particularly vulnerable, not only because they lose some of their taste - a factor that changes their eating habits - but they also lose some of the body's processes necessary for digestion, absorption and assimilation of food. Where there is doubt that the diet does not meet the needs of all nutrients, supplementation is positive.
The amount of nutrients present in the earth where our food grows affects the quality and quantity of vitamins present in the foods we consume. Insufficient nutrient levels lead to nutrient-deficient foods - another reason to take a supplement. Other causes of the loss of vitamins in the foods we consume include the handling and storage of packaged foods and the loss of substances during cooking.
Unless otherwise indicated, vitamins and minerals should be taken at mealtimes. Vitamin therapy does not produce noticeable results overnight, and the regeneration or biochemical alteration necessary to repair damage to the body takes weeks and sometimes months before there are noticeable benefits.
Taking too much of a given nutrient over a prolonged period of time can be toxic and damage the body. It can cause the loss of another nutrient in the urine, or it can damage, suppress or interfere with normal physiological processes. Studies have shown that when a certain amount of a given substance has reached an equilibrium, excess amounts can accumulate in the body without being metabolized. Vitamin C can be considered the exception because the intake of this substance above the norm is beneficial for its antioxidant effects.
Vitamin supplements can be of two types: natural and synthetic. At the molecular level, natural or synthetic vitamins are equally effective for the body. The exception is vitamin E. Synthetic forms of vitamin E do not bind firmly with the cell structure, Natural vitamins are organic, but not all organic vitamins are natural. Synthetic vitamins can be considered organic as long as there is a molecule in the formula that has at least one carbon atom. Organic vitamins come from animal and plant tissues but also from raw materials such as tar and wood pulp.Tar, for example, can be considered natural because it was formed over millennia from vegetable raw materials. Natural vitamins usually have lower potency. Synthetic nutrients are added both to increase potency and to stabilize and standardize the amount of nutrients in a batch.
Vitamins are usually divided into water-soluble and fat-soluble. Water-soluble vitamins, those of group B, vitamin C and the components called "bioflavonoids" are generally measured in milligrams.
Fat-soluble vitamins A, D, E, and K are measured in activity units, known as "International Units' (IU) or" United States Pharmacopoeia Units "(USP). Vitamins A, D, E, and K are in this book. expressed in International Units (IU) Beta-carotene, a water-soluble form of vitamin A, is also expressed in IU. Once opened, the tablet supplements should be stored in a cool, dry place (not the refrigerator), as contact with air reduces their potency. The tablets can be coated with a sweet or protein substance that can cause allergic reactions in some individuals. The contents of the capsules can be liquid or powder. Capsules are more recommended because they dissolve and are absorbed more easily than tablets, especially by those with digestive problems. An advantage of the powder-based capsules is that they can be opened and mixed with food or drinks for those who cannot swallow them or for those who want a quick assimilation.
Liquid forms, such as vitamin E, can be opened with a pin and applied directly to the affected area. The capsules are available in the same strengths as the tablets. Liquid form nutrients are easier to ingest and are especially suitable for children and the elderly. Vitamin C is available in liquid form and is indicated for colds and flu. Liquids must be kept in the refrigerator because, once opened, they quickly lose their effectiveness. The powder is also suitable for children and the elderly and is especially suitable for the intake of amino acids. Topical drops and ointments are also available.
The US Recommended Daily Intakes (RDAs) and Food Goals for the nutrients mentioned in this book are based on the standards set by the Food and Nutrition Board of the National Research Council (USA). Those in the RDA represent the optimal levels for those vitamins known to be essential for a healthy organism. They are based on reliable scientific knowledge and are considered adequate for the nutritional needs of virtually all healthy individuals. These levels are intended as applicable for individuals whose physical activity is considered light and who live in temperate climates and have a safety margin for each vitamin greater than the minimum necessary for the health of the organism. The RDAs consider the amount of nutrients the body should only absorb from food. For example, since the body only absorbs 10% of the iron ingested with food, the RDA ranges from 10 to 18 mg to compensate for lost iron. The same principle is applied to the other minerals. Since each individual is different, it is impossible to establish precise doses.
Minerals are nutrients that exist in the body and in food in organic and inorganic combinations. About seventeen minerals are essential in human nutrition. Although only 4 or 5 percent of the human body is made up of minerals, minerals are vital for mental and physical well-being. All tissues and internal fluids of living organisms contain varying amounts of minerals. They are fundamental constituents of bones, teeth, soft tissues, muscles, blood and nerve cells and play an important role in physiological processes, strengthening the structures of the skeleton and preserving the vigor of the heart and brain, as well as that of all muscles and the nervous system.
Minerals help maintain the delicate water balance in the body, essential for the proper functioning of mental and physical processes. They prevent fluid tissues and blood from becoming too acidic or too alkaline and allow other nutrients to pass easily into the circulatory system. They also promote the transport of chemicals in and out of cells and help in the production of antibodies.
Calcium, chlorine, phosphorus, potassium, magnesium, sodium and sulfur are known as "macrominerals", as their presence is relatively high in the body's tissues and are measured in milligrams. Other minerals, called "trace elements", are present in the body only in very small quantities but are essential for a good functioning of the organism. Trace elements are measured in micrograms.
Minerals, as well as vitamins, act as catalysts for many biological reactions within the human body, including muscle response, transmission of messages through the nervous system, digestion and metabolism for the utilization of the nutrients contained. in foods. They are also important for hormone production.
Minerals coexist with vitamins and their functions are interrelated. For example, some B complex vitamins are absorbed only when combined with phosphorus, vitamin C strongly promotes iron absorption and calcium absorption does not occur except in the presence of vitamin D. Zinc helps vitamin A to be released from the liver. Some minerals are even part of the vitamins: vitamin B, contains sulfur and cobalt B12.
Most vitamins are easily absorbed by the body, but minerals are not. One of the forms of minerals that is most effectively absorbed by the body is the one chelated with amino acids. Studies show that when a mineral binds to an amino acid during digestion, the amino acid effortlessly carries it through the intestinal wall into the bloodstream. Minerals that do not bind to amino acids can bind to phytic acid (coming from cereals) which prevents their absorption. For this reason it is essential to consume complete proteins with every meal.
Amino acids occur naturally along the intestinal wall and act as receptors for minerals. A mutual attraction is between the two elements; but sometimes even if a mineral is in the right position, it may not have the opportunity to attach itself, because a chemically similar mineral competes for the same amino acid transporter. If there are not enough transporters or locations available.
The weaker mineral misses the opportunity. If minerals move along with a mass of food, they can be dragged along without having the ability to attach to an amino acid. Although minerals are treated separately, it is important to note that their actions in the body are interrelated; no mineral can act without involving others. Emotional and physical stresses cause an increase in the body's need for minerals, and a lack of them often leads to disturbances that can be eliminated by adding missing minerals to the diet.
It has been known for several years that foods contain other substances in addition to vitamins, minerals and energy-producing nutrients. Experts are discovering these substances one by one. The more we go forward with our discoveries, the clearer the role these substances play together with known nutrients in keeping our bodies healthy. We list some of these substances below:
- Antioxidants(clicca qui per saperne di più)
- Phytochemicals(clicca qui per saperne di più)
By the time it emerges from the warm, watery liquid of the womb, a newborn's body is made up of 77% water.
The percentage of water in the body of a child is instead 59% and that of an adult varies from 45 to 65%. In the blood we find 83% water, 82% in the kidneys, 75% in the muscles, 74% in the brain, 69% in the liver and 22% in bones. Water is the main element of the fluids that surround and are within all living cells. Breathing, digestion, assimilation, metabolism, removal and elimination of waste, as well as temperature regulation are all bodily functions that can only be performed in the presence of water. Water is essential for dissolving and transporting nutrients such as oxygen and minerals through the blood, lymph and other body fluids. Water also balances the pressure, acidity and composition of all chemical reactions.
Only oxygen is more important than water in the life of any organism. Humans can survive about 5 weeks without proteins, carbohydrates and fats, but only 5 days without water in mild climatic conditions. The circulation of water between the blood and the organs is continuous and is always maintained in a balanced condition.
Most of this water is removed by the kidneys, where all of our blood passes to be filtered 15 times in an hour. The body eliminates a certain amount of it daily through evaporation or excretion and this amount must be replaced. Whenever the body overheats, two million sweat glands secrete sweat which is made up of 99% water. The heat from the blood evaporates the sweat, cooling the body and thus keeping the internal organs at a constant temperature.
Minimal but substantial water loss also occurs during breathing and tearing. The vapor is exhaled through the moist walls of the nose and lungs. Dry air takes away more water than humid air. Small tear ducts bring a liquid solution to the eyelid that lubricates the eyes 25 times per minute. The tears then pass into the nose where they evaporate.
To replace lost water, the body, under normal conditions, needs about three liters per day. This need can be increased by particularly tiring activities, very hot climates or diets very rich in salt. The sensation of thirst (as well as that of sleep, hunger, satiety and sexual urges) is controlled by a part of the forebrain called the hypothalamus. Metabolic water is a by-product of the food combustion process and can reach the amount of half a liter per day. Foods provide up to one and a half liters. For example fruit and vegetables are made up of 90% water. Even dry foods such as bread and crackers are made up of 35% and 5% water respectively. Drinking water is the other source of reintegration.
Unfortunately, bacteria, viruses, synthetic compounds, metals and radionuclides can become part of our drinking water. The health consequences can range from minor illnesses such as colds and flu to cancer.
Most of the bacteria in the water are harmless, but some can cause disease. Among these we find Pseudomonas, Flavobacterium, Achromobactet Proteus- Klebsiella, Bacillus Serratia, Corynebacterium, Spirillum, Clostridium, Arthrobacter, Hallionella, and Leptothrix. Flavobacterium can create complications in the postoperative course. Pseudomonas can be added to post-operative infections, burns and infections of the intestinal and urinary tract. Klebsiella Pneumoniae produces infections of the nose, throat, respiratory and genitourinary tract, and can also be a cause of meningitis and septicemia. Coliphons are found in the intestinal tract of humans or warm-blooded animals and are a good indicator of contamination of water supplies with fecal matter. Escherichia coli (E. Coli) causes severe inflammation of the abdominal organs and membranes; Salmonella (also present in ice cubes) causes typhoid and intestinal fevers and Shigella causes various forms of enteritis and dysentery. The analyzes carried out on drinking water show that the total density of coliforms is one of the parameters of the law on the safety of drinking water most frequently not respected. Fluoride, which is added to drinking water to kill bacteria, can be carcinogenic if added in excessive quantities. Drinking water contains harmful toxins. Cumulative toxins are substances taken in small doses that are stored by the body. The human body has developed processes that allow it to effectively expel ingested toxins. However, when this exposure to toxins becomes chronic or continuous, or when new substances arise, unfavorable reactions can occur. Substances such as arsenic. chromium, radioactive substances, pesticides and many other industrial contaminants are retained in the body and accumulate in certain organs such as the liver, skin, bones or adipose tissues, from which they are later gradually released, and cause diseases such as the cancer.
In research carried out in the laboratory, the purification methods that have proved most effective in eliminating contaminants have been those of distillation and reverse osmosis. Other methods, including coal-based methods, remove some, but not all, forms of contaminants.