No one argues with the fact that the fish is useful. Indeed, due to its high nutritional value, fish has a wide positive effect on the entire body. In fish products, the true health formula is hidden: highly digestible proteins, fatty acids, vitamin D and a variety of minerals, such as iodine, selenium, fluoride, magnesium, calcium. So, the composition and nutritional value of fish and fish products is the topic of conversation for today.
Ironically, the composition of fish meat depends on many factors, such as species, age, type of food, the habitat of the individual. However, in any case, fish is a valuable food product. The percentage of protein in fish products (1957-1982%) is much higher than in meat of animals, which are grown for slaughter. Fat content is only about 5%, and the protein (useful protein) and carbohydrate content limit is up to 27%. No other food product can provide the human body with so many nutrients at once. And, those that are easily digested and do not become excess fatty tissue.
Fish can be divided into several species by origin (sea fish, freshwater fish), or by the content of fat. Sea fish is richer in fat than fish that live in fresh water, and therefore contains more omega-3 substances. In marine fish, more iodine, but in freshwater fish, more phosphorus - a substance necessary for normal brain function. Again, oily fish is more caloric, although it is valued above the river. Here is what the classification of fish looks like in terms of key indicators:
By origin:
- sea fish: salmon, mackerel, tuna, herring, halibut, cod, sprat, Baltic herring and others
- Freshwater fish: bream, catfish, carp, carp, trout, tench, roach, sturgeon, zander and others
By fat content:
- lean fish: hake, cod, tilapia, sea bass, kerguelen, tench, pike, pollock, pangasius, bream, roach.
- medium-fat fish: trout, river perch, carp, flounder.
- fatty fish: halibut, salmon, eel, tuna, herring, mackerel, sardines, sprats.
What is valuable to us fish and fish products?
Omega-3 fatty acids
The most important nutrient rich in fish is the fatty acids of the omega-3 family. In fatty fish you can find a group of special acids that affect the metabolism and metabolism of a person. It is worth noting that the fish of the northern seas contain more useful acids than the southern ones. These acids are found only in fish. In vegetable food products one can find their analogue -alpha-linolenic acid (linseed, rapeseed, soybean oil), but it has much less useful effect in the body. What gives the body the omega-3 acids contained in the fish?
- positively affect the cardiovascular system, protect against the formation of atherosclerotic plaques
- reduce the risk of heart rhythm disorders, protect against myocardial infarction, reducing blood coagulability
- stimulate the production of vasodilator nitrogen, which promotes blood flow and lowers blood pressure
- lead to an increase in the level of "good" cholesterol, promote the restoration of equilibrium in the concentration of cholesterol in the blood
- reduce the risk of cancer
- are important for good appearance of the skin, hair, nails
- act as an excellent anti-inflammatory drug, which is important for people suffering from arthritis, gout
- they are necessary for the proper functioning of the nervous and immune systems
- encourage the increase in the production of serotonin - a hormone of good mood
How does the content of these beneficial acids look like in fish and seafood? So, salmon - 1.8 g / 100 g, sardines - 1.4 g / 100 g, mackerel - 1.0 g / 100 g, tuna - 0.7 g / 100 g, halibut - 0, 4 g / 100 g, cod - 0.1 g / 100 g, mussels - 0.7 g / 100 g, oysters - 0.5 g / 100 g, shrimps - 0.3 g / 100 g. , tilapia - only about 0.08 g / 100 g.
Iodine
Another important component in the composition of fish and fish products, which determines their nutritional value, is iodine. This is a very important element for the proper functioning of the body, since it is part of the thyroid hormones. They manage the metabolism in the body, responsible for its growth, maturation, thermogenesis, the harmonious work of the nervous system and the brain. Iodine contributes to the combustion of calories in the body, improves digestibility of nutrients and concentrates them precisely in those organs that need it most. Deficiency of iodine leads to diseases and irreversible processes in the thyroid gland. The level of iodine in the body affects the formation of willpower, mental development (or backwardness), its lack can lead to a delay in physical and mental development, miscarriages, cretinism. Absorption of iodine from food (and from fish in particular) reduces these risks at times.
Selenium
Selenium is another element that is rich in fish and fish products. Its bioavailability is extremely high (50-80%), and its content in food depends on the content of selenium in their environment of growth or habitat. Selenium is an element with antioxidant activity, so it protects the body from aging, and also has a protective effect against cancer. Selenium is also important for the normal functioning of the genitals, it is part of the enzymes in red blood cells and is necessary for the normal growth and development of this system. Deficiency of selenium produces such symptoms as muscle weakness, cardiomyopathy or suppression of growth in children. In areas where the content of selenium in the environment is too high in people absorbing excessive doses of selenium, there are side effects such as hair loss, nails, skin damage. The amount of selenium in the fish is small, but it is just as much as the human body needs in the norm. If, of course, the fish were not fed additional selenium-containing food, which would lead to an excess of selenium in the final fish product.
Viatin D
Fish is also a source of vitamin D, which is indispensable in the work of the intestines, kidneys and bones. In the intestines, absorption of calcium and phosphorus is stimulated, which helps to strengthen the bones and influence the correct construction of the skeleton. The lack of vitamin D can negatively affect the bone system in children (rickets) and in adults (osteoporosis, osteomalacia). Its content in fish depends on the fat content: halibut - 5 μg / 100 g, salmon - 13 μg / 100 g, mackerel - 5 μg / 100 g, sardines - 11 μg / 100 g, tuna - 7,2 mcg / 100 g, herring - 19 mcg / 100 g.
Calcium
The greatest amount of calcium is found in the bones of fish. Therefore, if you need calcium, buy minced fish. It is grinded from a whole carcass of fish along with bones, so that calcium there will be in excess. This element is important for the nervous system, muscles, normal heart rhythm and is a necessary condition for maintaining the alkaline balance in the body. A lack of calcium is usually seen with the naked eye: problems with bones and teeth, as well as frequent muscle spasms and outbursts of anger. To calcium is easily absorbed by the body, it is necessary to have vitamin D and the corresponding ratio of this element to phosphorus (1: 1). That is why fish and fish products are the best supplier of calcium. They have all the ingredients to ensure that calcium is fully absorbed and was the most useful for the body.
Magnesium
Fish also contain magnesium. Its digestibility, as in the case of calcium, requires special conditions. The presence of fat is necessary so that magnesium can be absorbed by the cells of internal organs. This is important for bones, nervous, cardiovascular, muscle systems and body mass formation. Magnesium is involved in the metabolism of carbohydrates, calcium, sodium, potassium, phosphorus, vitamin and affects the action of antidepressants. Therefore, if the diet is too few products containing magnesium, there is depression, hyperactivity of the nervous and muscular systems, muscle spasms, convulsions. Its content in fish is as follows: cod - 5 mg / 100 g, halibut - 28 mg / 100 g, salmon - 29 mg / 100 g, mackerel - 30 g / 100 g, sardines - 31 g / 100 g. tuna - 33 g / 100 g, herring - 24 g / 100 g.
Despite the highly nutritious composition and nutritional value of fish and fish products, the consumption of fish in our country is only about 13 kg. per capita per year. For comparison: the Japanese consume fish about 80 kg. per person per year, Germans, Czechs and Slovaks - 50 kg., French, Spaniards, Lithuanians - 30-40 kg.