Foods high in protein plant and animal origin

The debate about whether the proteins of plant origin to be a complete substitute for proteins contained in animal products, has been underway for a long time. Scientists use to assess the value of such categories of proteins as biological value, protein digestibility, protein efficiency ratio, and others.

The most important of these categories is probably biological value - a measure of the biological activity of the protein, indicating what percentage of the proteins contained in the product is indeed absorbed by the body. The high protein content in food is not always equal to their high biological value. By stoballnoy scale biological value of common foods that contain large amounts of protein, it is estimated as follows:

• Egg - 93.7;
• Milk - 84.5;
• Fish - 76;
• Beef - 74.3;
• Soybeans - 72.8;
• Figure - 64;
• Whole wheat - 64;
• Corn - 60;
• Dried beans - 58.

It is obvious that even the most valuable vegetable source of protein - soy - protein provides the body is not as efficient as dairy products or meat.

Additionally, a very important factor that affects the value of the protein products to humans, is the content of amino acids. They are in any proteinaceous food not only in some foods contain all amino acids necessary for man. They are called sources of full or full, proteins, and include virtually all sources of animal protein. The other protein foods lacks one or more amino acids - is incomplete or defective proteins, including, mainly, cereals, legumes, nuts, vegetables.

If a person refuses only meat he can get complete protein from eggs and dairy products. But vegans - people who are excluded from the diet of all animal products, in order to provide themselves with a sufficient amount of quality protein, you need every day to eat a lot of different protein products of vegetable origin (primarily - soy-based products), and taking certain supplements Food additives - basic classification .

On the other hand, many sources of animal protein, especially - red meat, contain a lot of fat. For beef steak weighing 170 g dose contains most valuable protein - about 40 g, and 38 g of fat, including - 14 g saturated fat. That - more than 60% of the recommended daily intake of this type of fat. The same portion of salmon provide you with 34 g protein and 18 g fat, only 4 g of which - saturated fats. One cup of cooked lentils 18 g of protein and less than one gram of fat.

When deciding which sources of protein and how much to include in your diet, be sure to consider not only their biological value, but also fat. According to many nutritionists, red meat (pork, beef, lamb) should be eaten infrequently and in small amounts - no more than two servings weighing 85 g per week. From bacon and sausage is better to give - they contain a lot of protein, but their composition also includes an excessive amount of fat.

The best sources of protein include fish, poultry, eggs and dairy products - they contain protein is well absorbed, and are relatively low in saturated fats. Legumes, nuts and seeds experts call additional sources of protein - they are certainly very useful, but it should not completely replace their animal protein.

Cancer and Vitamin E

Antioxidants, which include vitamin E to protect cells from the damaging effects of free radicals, which can contribute to the development of cancerous tumors. Vitamin E may also inhibit the formation of carcinogenic nitrosamines, which are formed in the stomach of the nitrite contained in the food. Finally, the ability of vitamin E to improve the immune system can also prevent the development of cancer. Unfortunately, studies in which researchers have tried to link the consumption of vitamin E with a probability of cancer, have shown that in most cases, this vitamin can hardly be regarded as an effective preventive measure.

Among the participants of one study, which is being watched for seven years, almost equally often fell ill with cancer and those who took a daily 400 IU vitamin E and those who took a placebo Placebo - an effective tool for self-hypnosis . This study included people over 55 years old, had a history of heart disease or diabetes. Vitamin E did not reduce the risk of cancer in women who took a day for the 600 IU of vitamin E.

Several studies have examined the relationship between vitamin E intake and prostate cancer risk. In one such study involved 29,000 men; the risk of cancer was approximately the same in those taking vitamin E and placebo. However, smokers and those who quit smoking, intake of more than 400 IU of vitamin E per day resulted in a statistically significant (71%) reduction in the likelihood of developing prostate cancer.

In another clinical trial involving 29133 male smokers has been found that daily doses of 50 IU of synthetic vitamin E over 5-8 years, reduced the risk of prostate cancer by 32% (compared with subjects taking placebo).

Upon receipt of such promising results, it was decided to conduct another study. Within its framework, the scientists plan to determine whether long-term use helps (7-12 years) synthetic vitamin E (400 IU, in the form of DL-alpha-tocopherol), together with selenium (200 micrograms per day) or without, to reduce the likelihood of developing prostate cancer . The study involved 35,533 healthy men aged 50 years and older. It was discontinued earlier than planned, when it became clear that taking vitamin E (including in combination with selenium) for 5, 5 years does not help reduce the chance of prostate cancer.

Observations of subjects in the next half year (at this time, they have not received vitamin E and selenium) have shown that men who previously took vitamin E risk of prostate cancer was 17% higher than in those who received only placebo and this is a statistically significant difference. The risk was even slightly higher in men taking selenium, but the difference was insignificant. The likelihood of developing other types of cancer in all groups of patients were similar.

Until now, only the results of the study showed that the consumption of large doses of vitamin E (as of food additives Food additives - basic classification And from foods) may reduce the risk of cancer. In this clinical trial involved women under 65 years old, and they took a 35.7 IU of vitamin E per day. In the test, there was significant reduction in the risk of developing colon cancer. However, during the next test, in which more than one hundred thousand people, to repeat these results failed. The research is conducted with the participation of more than 18,000 postmenopausal women did not show that vitamin E may reduce the risk of developing breast cancer. In another study it was found that prolonged intake of vitamin E (for ten years or more) reduces the likelihood of death from bladder cancer Urinary bladder - structure and function Although the risk of developing the disease, apparently, is not reduced.

Cognitive abnormality

The brain consumes a very large amount of oxygen, and in the membranes of neurons contains a lot of polyunsaturated fatty acids. Scientists theorize that if the neuronal damage caused by free radicals, may eventually lead to cognitive and neurodegenerative diseases such as Alzheimer's disease, the sufficient intake of antioxidants Antioxidants: the truth about the notorious benefits   may to some extent protect against these diseases. This hypothesis is confirmed by the results of the clinical trial, which was attended by 341 patients with a moderate form of Alzheimer's disease. The patients took placebo, vitamin E (DL-alpha-tocopherol, 2000 IU per day), a monoamine oxidase inhibitor (selegiline), or both vitamin E and selegiline. During the two years of observation, scientists have concluded that patients taking vitamin E and selegiline, together or separately by Alzheimer's disease progresses more slowly than those taking placebo. These patients rarely needed help to care, they last longer retained the ability to independently perform daily activities.

Another study, which was attended by people aged 65 to 102 years old, showed that consumption of high doses of vitamin E - from food or supplements - slows the deterioration of cognitive functions in the elderly. In two other studies, however, failed to show that vitamin E can slow the progression of Alzheimer's disease. Currently specialists usually not recommended for vitamin E as an agent for the prevention of cognitive disorders. There will be more research that may help us to understand how vitamin E is associated with age-related impairment of mental functions - unless, of course, such a connection exists.