How to cook — to boil or fry?

It is well known that when heated to cooking destroyed some vitamins and other nutrients. But heat treatment also leads to the formation of new substances, which are still poorly understood.

Therefore, to determine the harmfulness of thermally processed products, in addition to scientific research, it is possible to use experimental methods. For example, the feelings of the people with hypersensitivity of the organism to the food.

In 1977, Valentin Nikolayev (son of Professor Nikolaev Yu. s.) went on a raw food diet. Then he ate only raw plant foods — fruits, vegetables, nuts, and greens. But in celebration of the New year I decided to check what happens if you eat regular food like salads, pies, cakes, candies. On the morning of 2 January, Valentine could barely move. He had a severe headache, it was hard to breathe, when attempting to walk swayed and swerved. After only two days of fasting Valentin was able to go to work.

The question arose — what Christmas food is the most poisoned?

After experimenting with different products, Valentine made up a "table of harm" thermally processed foods (see below). Later the experimental results were confirmed with other raw foodists.


Simplified table of hazard V. Nikolaeva, scores

Coffee, chocolate, burnt sugar (caramel), butter 90-100 fried Potatoes, bread 50-60 Tea, rice, cheese, buckwheat, milk, peas, eggs, pasta, cabbage cooked

5-20 Sugar, rice, fruits, meat, fish 0

I do not recommend to switch to a raw food diet, so in the table are only interested in the top row. At first glance, it is not clear why coffee and chocolate were some of the most harmful heat-treated products. The fact that coffee beans and cocoa beans are roasted in the workplace. The natural color of coffee beans — green, black they are because burn when frying, it is burned product.

Reaction to caramel predictable. During heat treatment of glucose, and especially fructose, accelerates the Maillard reaction, the formation of many harmful substances.

According to Valentin Yuryevich, fried vegetable oil is slightly worse than the fried animal fats. A similar reaction can give and the crude oil after long-term storage.

This table should not be taken as a General assessment of the hazards of the product, it shows only the effect of substances formed during heat treatment, on the body raw foodists.

It is unknown what caused the extent of this influence. As already mentioned, there is definitely not useful for all people products.

Chocolate contains not only products of burning cocoa beans, but also antioxidants, vitamins, zinc and other minerals, cocoa improves the composition of the microflora. Coffee also has many benefits, the main thing — not to abuse. But burnt sugar or fried butter not give anything useful, these products are definitely harmful to the body. Scientific research provides the opportunity to partially explain the results of the experiments of Nikolaeva (see table. below).


Harmful substances in products that are heated significantly above 100°C

  Harmful substancethe Product



Review 1 Gidroksimetil-furfural (HMF), Sugar, sweets

(fructose, glucose)

HMF is formed during the heating of sugars, especially fructose. That is why it is not recommended to heat the honey.

HMF contains not only honey, but also in caramel, jam, especially that long cooked.

Burnt sugar tint Coca-Cola, cognac, and other drinks.

HMF can be formed even without heating, especially in an acidic environment.

Large doses of HMF cause convulsions and paralysis, small depress the nervous system.

Our ancestors used honey is not often, therefore, the human body is not adapted to the detoxification of HMF and it accumulates in the liver.

2 advanced glycation End products (CNG, AGE) (amino acid + fructose or glucose) In our time, scientists are actively investigating CNG — a group of substances which are formed by the reaction of simple carbohydrates with amino acids. CNG can provoke the development of many diseases — cardiovascular, diabetes, accelerate aging.

CNG is contained not only in the products subjected to heat treatment, but in the raw.

The higher the temperature and the longer the cooking, the more product is formed the KPD.

Studies in mice showed a significant increase in life expectancy from reducing the number of CNG diet.

3 Acrylamide Coffee, cocoa, grain, potatoes

(asparagine + fructose or glucose)

Acrylamide is the product of glycation, its dangers had been known for a long time. Scientists knew that it contained in tobacco smoke, is toxic and can cause cancer. Therefore, the content of acrylamide in water was regulated.

In 2002, Swedish scientists discovered acrylamide in many food products, and standards were exceeded in the tens of thousands of times.

Further studies clarified that this substance is formed in the reaction between the amino acid asparagine and simple carbohydrates at temperatures above 180°C. that is, the acrylamide contained in fried, burnt products and pripiceni (blackened) crust.

The formation of acrylamide is one of the stages of the Maillard reaction. Valentin Nikolaev notes that the bread crust gives a more severe reaction than the crumb.

4 Aldehydes,

free radicals

conjugates LCD

Fats, especially


oils (Pufas)

Aldehydes formed during frying of vegetable oil, can contribute to the formation of tumors and diseases of the brain.

Free radicals oxidize molecules in the body, accelerating aging, causing CVD and other diseases.

5 Nitrosamines Sausage, other

store meat products (nitrate + amino acids)

Nitrosamines are formed from nitrates in the presence of amino acids and high temperatures. In industrial meat products specifically add nitrates to get a beautiful pink color. And then there is processing at high temperatures, creating ideal conditions for the formation of nitrosamines.

Nitrosamines, provoke cancer.


Today the best defenders of the body from CNG and glycation are considered intermittent fasting and the substance sulforaphane, which is contained in the raw broccoli. Pre-marinating of meat and other foods in an acidic medium reduces the formation of KPG in the thermal processing of at least two times.

Characterization methods thermal processing Method inReview 1 Cooking product Treatment, totally immersed in boiling water or other liquid (except fat and sugar). The temperature reaches 100°C, in a pressure cooker to 120°C.

Like other methods of heat treatment, cooking destroys part of the vitamins, all enzymes and partially fiber. Part of the substances (both beneficial and harmful) goes into the water.

So after cooking, store-bought vegetables or meat water is better pour.

2 For a pair Product orietta hot steam, not immersed in liquid. The temperature can fluctuate in the range 75-120°C, depending on the configuration of a double boiler.

A lower temperature allows you to keep more nutrients in the product.

3 Quenching Is done under the hood in the presence of water and fat. The presence of water does not allow the temperature to rise significantly above 100°C.

If frying in a pan add water and cover, will be more useful stew.

4 Bake (except for crust)

Processing in the furnace/the oven, where a same temperature on all sides of the product. While the food there is moisture, temperatures will not rise much above 100°C. If the edges of the product the moisture has evaporated, the temperature rises and forms a blackened crust containing acrylamide and other harmful substances.

The appearance of any darkened by the temperature of the product is better not to use it.

To reduce the time of heat treatment and prevent the formation of crusts, I bake thin bread on the grill and not the pan. On the grill the moisture evaporates in two directions, not just upwards, that allows to reduce time of heat treatment. In addition, air has less heat transfer than metal, and the bread does not burn on the bottom.

5 On an open fire Studies show that when cooking on an open fire are harmful substances (including smoke), in particular, benzopyrene, CNG. Although our ancestors used this method of food processing that humans have not adapted to these substances.

Therefore, the use of barbecue you want to limit.

Before any heat treatment the meat marinate in an acidic marinade, which reduces the formation of KPG in 2 times.

6 Roasting In the processing of the product is at the layer of hot fat. The temperature can reach 140-200°C. In this process, many new substances.

In particular, at high temperatures produces acrylamide, benzopyrene, CNG, HMF, aldehydes, conjugated LCD, the formation of other toxic and carcinogenic substances. And suffers not only the surface of the product, as fried fat permeates the food.

Therefore, it is better never to fry. Our ancestors cooked and baked food in oven or on open fire, and not fried in the pan.

If you can not completely abandon this method of treatment, use animal or hard vegetable fats. Fried fat is the least harmful coconut oil (90% saturated FA).

But food can be heated in the pan, if you constantly stir. And remember that the ideal temperature of the food is body temperature, there is no need to heat it until hot.

7 In the microwave , it is believed that microwaves may affect nutritional value and safety of products. While the study did not prove any harm from microwave products.

But to reheat food in a plastic container clearly harmful.



Also interesting: Locavores: where was born — there and eat

3 transition rules for food live plant food


P. S. And remember, only by changing their consumption — together we change the world! ©



See also

New and interesting