The attitude of nutritionists towards vegetarianism has begun to change, especially in the West. And if earlier vegetarians most often became “the call of the heart”, now more and more people refuse meat, hoping to improve their health. Studies in recent decades have shown that overloading the body with animal protein, calories, and saturated fat increases the risk of many diseases.
Vegetarians usually become for moral, ethical or religious reasons – regardless of the opinion of doctors and even contrary to it. So, when Bernard Shaw fell ill one day, the doctors warned him that he would never recover if he did not urgently start eating meat. To which he replied with the phrase that became famous: “I was offered life on the condition that I eat a steak. But death is better than cannibalism” (he lived to be 94).
However, the rejection of meat, especially if it is accompanied by the rejection of eggs and milk, inevitably makes a significant gap in the diet. In order to remain complete and adequate, you need to not just replace meat with an equivalent amount of plant foods, but reconsider your entire diet.
PROTEINS AND CARCINOGENES
One of those who questioned the correctness of the postulate about the usefulness and necessity of animal protein was Dr. T. Colin Campbell, a graduate of the University of Georgia (USA). Shortly after graduation, the young scientist was appointed technical coordinator of an American project to improve child nutrition in the Philippines.
In the Philippines, Dr. Campbell had to study the reasons for the unusually high incidence of liver cancer among local children. At the time, most of his colleagues believed that this problem, like many other health problems among Filipinos, was due to a lack of protein in their diet. However, Campbell drew attention to a strange fact: children from wealthy families who did not experience a lack of protein foods most often fell ill with liver cancer. He soon suggested that the main cause of the disease is aflatoxin, which is produced by a mold that grows on peanuts and has carcinogenic properties. This toxin entered the body of children along with peanut butter, since Filipino industrialists used the most poor-quality, moldy peanuts for oil production, which could no longer be sold.
And yet, why did wealthy families get sick more often? Campbell decided to take seriously the relationship between nutrition and the development of tumors. Returning to the US, he began research that would last nearly three decades. Their results showed that the high protein content of the diet accelerated the development of tumors that were at an early stage of development. The scientist drew attention to the fact that mainly animal proteins had such an effect, among them milk protein casein. In contrast, most plant proteins, such as wheat and soy proteins, did not have a pronounced effect on tumor growth.
Could it be that animal food has some special properties that contribute to the development of tumors? And do people who eat mostly meat really get cancer more often? A unique epidemiological study helped test this hypothesis.
CHINA STUDY
In the 1970s, Chinese Prime Minister Zhou Enlai was diagnosed with cancer. The disease had by then reached the terminal stage of the disease, and yet he ordered a nationwide study to find out how many people in China die each year from various forms of cancer, and possibly develop measures to prevent the disease.
The result of this work was a detailed map of the death rate from 12 different types of cancer in 2400 counties among 880 million people for the years 1973-1975. It turned out that the mortality rate for different types of cancer in different areas of China had a very wide range. For example, in some areas, the death rate from lung cancer was 3 people per 100 per year, while in others it was 59 people. For breast cancer, 0 in some areas and 20 in others. The total number of deaths from all types of cancer ranged from 70 people to 1212 people for every 100 thousand per year. Moreover, it became obvious that all diagnosed types of cancer chose approximately the same areas.
In the 1980s, Professor Campbell’s Cornell University was visited by Dr. Chen Jun Shi, deputy director of the Institute of Nutrition and Food Hygiene of the Chinese Academy of Preventive Medicine. A project was conceived, to which researchers from England, Canada and France joined. The idea was to identify the relationship between dietary patterns and cancer rates, and to compare these data with those obtained in the 1970s.
By that time, it had already been established that Western diets high in fat and meat and low in dietary fiber were strongly associated with the incidence of colon cancer and breast cancer. It was also observed that the number of cancers increased with increased adherence to the Western diet.
The outcome of this visit was the large-scale China-Cornell-Oxford Project, now better known as the China Study. 65 administrative districts located in different regions of China were selected as objects of study. Having studied in detail the nutrition of 100 randomly selected people in each district, scientists have received a fairly complete picture of the nutritional characteristics in each district.
It turned out that where meat was a rare guest on the table, malignant diseases were much less common. In addition, cardiovascular diseases, diabetes, senile dementia, and nephrolithiasis were rare in the same territories. But all these diseases in the West were considered a common and inevitable consequence of aging. So common that no one ever thought about the fact that all these diseases can be the result of malnutrition – diseases of excess. However, the China Study pointed to just that, because in areas where the level of consumption of meat by the population increased, the level of cholesterol in the blood soon began to rise, and with it the incidence of cancer and other chronic diseases.
EVERYTHING IS GOOD IN MODERATION
Recall that the main building material of living organisms is protein, and the main building material for protein is amino acids. Proteins that enter the body with food are first disassembled into amino acids, and then the necessary proteins are synthesized from these amino acids. In total, 20 amino acids are involved in the synthesis of proteins, of which 12 can be rebuilt if necessary from carbon, nitrogen, oxygen, phosphorus, etc. Only 8 amino acids are not synthesized in the human body and must be supplied with food. That is why they are called indispensable.
All animal products are rich in proteins, which contain a complete set of 20 amino acids. In contrast to animal proteins, plant proteins rarely contain all the amino acids at once, and the total amount of protein in plants is less than in animal tissues.
Until recently, it was believed that the more protein, the better. However, it is now known that the process of protein metabolism is accompanied by increased production of free radicals and the formation of toxic nitrogen compounds, which play a significant role in the development of chronic diseases.
FAT FAT DIFFERENCE
Fats of plants and animals are very different in properties. Animal fats are dense, viscous and refractory, with the exception of fish oil, while plants, on the contrary, often contain liquid oils. This external difference is explained by the difference in the chemical structure of vegetable and animal fats. Saturated fatty acids predominate in animal fats, while unsaturated fatty acids predominate in vegetable fats.
All saturated (without double bonds) and monounsaturated (with one double bond) fatty acids can be synthesized in the human body. But polyunsaturated fatty acids, having two or more double bonds, are indispensable and enter the body only with food, playing an extremely important role. In particular, they are necessary for the construction of cell membranes, and also serve as a material for the synthesis of prostaglandins – physiologically active substances. With their deficiency, lipid metabolism disorders develop, cellular metabolism is weakened, and other metabolic disorders appear.
ABOUT THE BENEFITS OF FIBER
Plant foods contain a significant amount of complex carbohydrates – dietary fiber, or plant fiber. These include, for example, cellulose, dextrins, lignins, pectins. Some types of dietary fiber are not digested at all, while others are partially fermented by the intestinal microflora. Dietary fiber is necessary for the human body for the normal functioning of the intestines, preventing such an unpleasant phenomenon as constipation. In addition, they play an important role in binding various harmful substances and removing them from the body. Being subjected to enzymatic and, to a greater extent, microbiological processing in the intestine, these substances serve as a nutrient substrate for their own intestinal microflora.
GREEN PHARMACY OF FOOD PLANTS
Plants, including food ones, synthesize and accumulate a large number of biologically active substances of different structure, which participate in the vital processes of the human body and perform a wide variety of functions in it. These are, first of all, proteins, fats, carbohydrates, as well as vitamins, flavonoids and other polyphenolic substances, essential oil, organic compounds of macro- and microelements, etc. All these natural substances, depending on the method of use and quantity, ensure the normal functioning of the body and, if necessary, have one or another therapeutic effect. A large group of natural plant compounds that are not found in animal tissues have the ability to slow down the development of cancerous tumors, lower cholesterol and prevent the development of cardiovascular diseases, and stimulate the protective properties of the body. For example, these can be carrot and sea buckthorn carotenoids, tomato lycopene, vitamins C and P contained in fruits and vegetables, black and green tea catechins and polyphenols that have a positive effect on vascular elasticity, essential oils of various spices that have a pronounced antimicrobial effect, and etc.
IS IT POSSIBLE TO LIVE WITHOUT MEAT
As you can see, many important substances can only be obtained from plants, since animals do not synthesize them. However, there are substances that are easier to obtain from animal foods. These include certain amino acids as well as vitamins A, D3 and B12. But even these substances, with the possible exception of vitamin B12, can be obtained from plants – subject to proper diet planning.
To prevent the body from suffering from a lack of vitamin A, vegetarians need to eat orange and red vegetables, since their color is largely determined by the precursors of vitamin A – carotenoids.
It is not so difficult to solve the problem of vitamin D. Vitamin D precursors are found not only in animal foods, but also in baker’s and brewer’s yeast. Once in the human body, they are converted into vitamin D3 by photochemical synthesis in the skin under the action of sunlight with the help of photochemical synthesis.
For a long time it was believed that vegetarians were doomed to iron deficiency anemia, since plants lacked the most easily absorbed form of iron, heme iron. However, now there is evidence indicating that when switching to a purely plant-based diet, the body adapts to a new source of iron and begins to absorb non-heme iron almost as well as heme iron. The adaptation period takes approximately four weeks. An important role is played by the fact that in vegetarian food, iron enters the body along with vitamin C and carotenoids, which improve iron absorption. Iron needs are best met by a diet rich in legumes, nuts, wholemeal breads and oatmeal dishes, fresh and dried fruits (figs, dried apricots, prunes, blackcurrants, apples, etc.), and dark -green and leafy vegetables (spinach, herbs, zucchini).
The same diet also contributes to the normalization of zinc levels.
Although milk is considered the most important source of calcium, it is in those countries where it is customary to drink a lot of milk that the level of osteoporosis (senile thinning of bones leading to fractures) is highest. This once again proves that any excess in nutrition leads to trouble. Calcium sources for vegans are green leafy vegetables (such as spinach), legumes, cabbage, radishes, and almonds.
The biggest problem is vitamin B12. Humans and carnivores usually provide themselves with vitamin B12 by consuming food of animal origin. In herbivores, it is synthesized by the intestinal microflora. In addition, this vitamin is synthesized by bacteria living in the soil. Strict vegetarians living in civilized countries, where vegetables end up on the table after being thoroughly washed, are advised by nutritionists to take vitamin B12 supplements. Especially dangerous is the lack of vitamin B12 in childhood, as it leads to mental retardation, problems with muscle tone and vision, and impaired hematopoiesis.
And what about essential amino acids, which, as many remember from school, are not found in plants? In fact, they are also present in plants, they are just rarely present all together. To get all the amino acids you need, you should consume a variety of plant-based foods, including legumes and whole grains (lentils, oatmeal, brown rice, etc.). A complete set of amino acids is found in buckwheat.
VEGETARIAN PYRAMID
Currently, the American Dietetic Association (ADA) and Canadian Dietitians unanimously support a vegetarian diet, believing that a properly planned plant-based diet provides a person with all the necessary components and helps prevent a number of chronic diseases. Moreover, according to American nutritionists, such a diet is useful for everyone, in any state of the body, including pregnancy and lactation, and at any age, including children. In this case, we mean a complete and properly composed vegetarian diet, excluding the occurrence of any kind of deficiency. For convenience, American nutritionists present recommendations for choosing foods in the form of a pyramid (see figure).
The basis of the pyramid is made up of whole grain products (whole grain bread, oatmeal, buckwheat, brown rice). These foods should be eaten for breakfast, lunch and dinner. They contain carbohydrates, protein, B vitamins, minerals, and dietary fiber.
This is followed by foods rich in protein (legumes, nuts). Nuts (especially walnuts) are a source of essential fatty acids. Legumes are rich in iron and zinc.
Above are the vegetables. Dark green and leafy vegetables are rich in iron and calcium, yellow and red are sources of carotenoids.
Fruits come after vegetables. The pyramid shows the minimum required amount of fruit, and does not set their limit. At the very top are vegetable oils rich in essential fatty acids. Daily allowance: one to two tablespoons, this takes into account the oil that was used in cooking and for dressing salads.
Like any average diet plan, the vegetarian pyramid has its drawbacks. So, she does not take into account that in old age the building needs of the body become very modest and it is no longer necessary to consume so much protein. On the contrary, in the nutrition of children and adolescents, as well as people engaged in physical labor, there should be more protein in food.
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Studies in recent decades have shown that an excess of animal protein in the human diet underlies many chronic diseases. Therefore, although it is, of course, impossible to live without protein at all, you should not overload your body with it either. In this sense, a vegetarian diet has an advantage over a mixed diet, since plants contain less protein and it is less concentrated in them than in animal tissues.
In addition to limiting protein, a vegetarian diet has other benefits. Now many people spend money on buying all kinds of nutritional supplements containing essential fatty acids, dietary fiber, antioxidants and other widely advertised biologically active plant substances, completely forgetting that almost all of these substances, but at a more moderate price, can be obtained by switching to nutrition with fruits, berries, vegetables, cereals and legumes.
However, it should be remembered that any diet, including vegetarian, should be varied and properly balanced. Only in this case it will benefit the body, and not harm it.