The content of this article is from the Capital Science Lecture Hall sponsored by Beijing Association for Science and Technology, undertaken by Beijing Science Center, and co-organized by Beijing Science and Technology News. Academicians and experts are invited to give lectures every week to promote the spirit of science and help the public establish scientific ideas, master basic scientific methods, and understand necessary scientific and technological knowledge.
In recent years, the nutritional health of Chinese residents has improved significantly, but they still face problems such as the coexistence of undernutrition and overnutrition, and the frequent occurrence of nutrition-related diseases. Do you know the top 10 pitfalls of shopping at the supermarket?Do you know the "health killer" in the kitchen?Do you know how the science of "reducing salt, oil, and sugar" starts in the kitchen?Do you know the top 10 gossip on the dinner table?
In November, the Capital Science Lecture Hall held a series of lectures on the theme of "Science Guarding Health and Building a Healthy China". In this issue of the Capital Science Lecture Hall, Ruan Guangfeng, deputy director and associate research librarian of Kexin Food and Health Information Exchange Center, was invited to walk into Shangdi Bayi Community, Shangdi Street, Haidian District, to bring us a food safety "feast" in the kitchen.
Speaker:
Nguyen Quang Phong
Kexin Food and Health Information Exchange Center
Associate Director, Associate Research Librarian
How to eat safely and healthily at home (Part I).
How to eat safely and healthily at home (Part II).
** The greatest food safety riskMany people think it's safer to cook at home, but in fact, the biggest food safety hazard is in the kitchen.
In 2021, a total of 5,493 cases of foodborne illness were reported in China, of which 54% occurred at home. Of the 117 deaths, 92 per cent also occurred at home.
On October 5, 2020, a family of nine people in Jixi, Heilongjiang Province, suffered food poisoning after eating homemade sour soup at home, killing nine people. In 2019, a woman in Shenzhen became unwell and was poisoned after eating black fungus soaked for 3 days.
On October 5, 2020, a family of nine people in Jixi, Heilongjiang Province, suffered from food poisoning after eating homemade sour soup at home.
Both of the above foodborne illnesses were food poisoning outbreaks caused by the production of rice fermented acid by contamination with Pseudomonas coconut. Moreover, there is no specific drug for this type of poisoning, and the mortality rate is as high as 50%.
There are three major types of food that may be contaminated with Pseudomonas coconut in daily life: fermented cereal products (fermented cornmeal, pho, sour soup, syrup cake, glutinous rice cake, etc.), potato products (potato vermicelli, sweet potato noodles, potato starch, etc.), spoiled fungus and white fungus.
Many people are accustomed to making some fermented foods at home, such as stinky tofu and bacon, which are easy to be contaminated with Clostridium botulinum toxin, and then produce botulinum toxin to cause poisoning incidents. The mortality rate from botulinum toxin is generally 20% to 40%, and fermented soy and flour products, homemade sauces (bean curd, pasta paste), homemade bacon, and honey are "high-risk" foods for botulinum toxin.
In 2022, Ms. Wu from Zhengzhou, Henan Province, was poisoned by eating homemade stinky tofu.
From the perspective of food, it is mainly meat and aquatic products that are easy to cause poisoning, and there are many microorganisms in these foods, which can easily lead to food poisoning. Many people like to rinse raw meat bought from outside at home with water, which is wrong. During the process of washing meat, microorganisms in raw meat can splash on the countertop, other foods, cutting boards, etc., which can easily lead to contamination of other foods or dishes.
The correct way to do this is to soak and wash the raw meat in a special container (basin or bucket) as much as possible, especially not to rinse it with water with a very fast flow rate. If rinsing, try to place the meat at the bottom of the pool, and the water will flow more slowly and gently.
Many people treat the refrigerator as a safe, believing that the food is "foolproof" once it is placed in the refrigerator. In fact, there is a "dangerous molecule" in the refrigerator - listeria monocytogenes. Listeria monocytogenes has an important property: it is not afraid of the cold. It grows slowly at refrigerated temperatures as low as 0, and general freezing is not enough to kill them. According to statistics, nearly two-thirds of people infected with Listeria monocytogenes are confirmed to have Listeria monocytogenes in the refrigerator at home.
Listeria monocytogenes may hide in a variety of foods.
Listeria monocytogenes poses the greatest threat to pregnant women and their children, with 25 neonatal Listeria infections recorded in the country between 2000 and 2009, with a mortality rate of 56%.
How to defeat Listeria monocytogenes?Since Listeria monocytogenes has the characteristics of "being afraid of heat and not afraid of cold", the food taken out of the refrigerator should be heated to more than 70 in the center and last for more than 2 minutes, so that Listeria can be killed. In addition, it is necessary to avoid drinking raw milk, cheese and other dairy products that have not been pasteurized and thoroughly boiled, and not to eat cold meat, ham, braised meat and other meats that have not been thoroughly heated. At the same time, we need to clean and clean the refrigerator regularly, and the leftovers in the refrigerator cannot be eaten directly, but need to be heated thoroughly.
How should I store food in the refrigerator?First, try not to hoard too much food and eat it as soon as possibleSecond, use a crisper or bag to pack the food in advanceThird, keep a record of the expiration date and clean up the expiring food regularlyFourth, clean and disinfect the refrigerator regularly.
Common pitfalls of everyday shoppingWhen we buy food in supermarkets and wet markets, we often see the following shopping traps.
The first pitfall is "all-natural". Pure natural is not necessarily safer, for example, green beans contain a natural toxin called saponin, which can easily lead to poisoning if not cooked. In addition, a significant percentage of the various naturally growing mushrooms are poisonous mushrooms. In Yunnan, there are poisoning incidents that cause death due to the consumption of poisonous mushrooms every year. Therefore, people should be extra careful when buying so-called "all-natural" foods.
The second trap is "soil pressing, ancient methods". In many places, there are some cooking oils that are squeezed and made by ancient methods, and merchants claim that this oil is fragrant and delicious. But in fact, the so-called "earth-pressed, ancient" peanut oil has not been refined, and there are many impurities in it, such as aflatoxin, whose biggest risk is to cause liver cancer, which is a carcinogen.
The third pitfall is "no preservatives, zero additives". In fact, there is no such thing as soy sauce or vinegar with zero additives. The main role of preservatives in food is to inhibit the reproduction of harmful bacteria and prevent bacteria and molds from producing toxins in food. As long as the preservatives are added under the specified dosage, they will not cause harm to the human body. Nowadays, many foods emphasize that no preservatives are added, which seems to be the healthiest, but in fact, some foods will be easily contaminated by bacteria if they do not have preservatives, and there may be food safety hazards.
The fourth pitfall is "health efficacy". There is a stomach soda biscuit, and the merchant claims to be able to "neutralize stomach acid" and help you "nourish your stomach". In fact, it is an ordinary food, not a health food. China's food safety law stipulates that food and health food are not drugs and cannot be diseases. Any food that claims to have the effect of ** disease and other effects must be purchased with caution.
The fifth trap is "real and fake milk". Many people will buy some yogurt, but it is not milk at all, and the protein content of its product nutrition label is 1 gram 100 grams. In China's relevant standards, the protein content of fresh milk and fermented milk (yogurt) needs to reach 29 grams 100 grams or more;The protein content of prepared milk and flavoured fermented milk needs to be 23 grams 100 grams;The protein content of milk-containing beverages only needs to reach 1 gram or more than 100 grams;The protein content of lactobacillus drinks only needs to be greater than 07 grams 100 grams. Therefore, this yogurt is not milk at all, but a milk-containing drink.
The sixth trap is "sugar-free food". Many diabetics are worried that eating sugary foods will cause their blood sugar to rise, so they will buy sugar-free foods. However, many sugar-free foods are only sucrose-free, without adding white sugar, and may be added with fructose, fructose syrup or honey, which is not sugar-free food. There is a so-called sugar-free biscuit, the biscuit is made of flour, flour is starch, and diabetics can also raise blood sugar after eating.
The seventh trap is "zero fat". Some people feel that they have gained weight or are worried about high blood lipids and high blood pressure, so they will buy some "zero-fat" foods. However, some foods that claim "zero fat" have a nutritional profile, 146% is carbohydrates, which are actually sugars. As a result, some foods that claim to be "fat-free" are actually high in sugar.
The eighth trap is "non-fried". Many people may be worried about high blood pressure and think that there is no oil unless fried. However, some merchants claim that "non-fried" potato chips have 25 grams of fat per 100 grams in the nutrition content list, although it is not fried, but when the hot air is dried, in order to make the potato chips taste more crispy, a layer of oil will be sprayed on them, which is not much different from frying.
The ninth pitfall is "no trans fatty acids". Many people think that eating too much trans fat is not good, and will buy some foods that are "trans free of trans fatty acids" or "zero trans fatty acids". We need to pay more attention to the nutrient facts list when buying food, some foods with zero trans fatty acids, which seem to be healthy, may contain a lot of sugar and sodium, and sodium intake is mainly through table salt. Trans fatty acids and table salt are also factors that can contribute to cardiovascular disease. Therefore, so-called "trans fatty acid-free" foods are not necessarily healthy.
The tenth trap is "zero sugar substitutes". Nowadays, many people like to eat sugar-free foods and will choose "zero sugar substitute" foods. For example, a sparkling water, in fact, did not add anything, but filled a little gas, advertising that it does not add any sugar substitutes, "zero sugar substitutes". In fact, it is a superfluous move, because it is water, and there is no sugar in itself, and it is deliberately said.
The eleventh trap is "vacuum freeze-drying". One claims to be vacuum-freeze-dried shiitake mushroom chips, and in its ingredient list, the first is shiitake mushrooms and the second is vegetable oil. In its nutrition facts list, the fat content is 23 grams per 100 grams, which is actually the same as the so-called "non-fried" potato chips.
How can I avoid these pitfalls?First, look at the nutrition label. If you want to eat less oil, choose one with less fat;If you want to control your blood sugar, choose one with less carbohydrates;If you want to eat less salt, choose one with less sodium.
The second one looks at the ingredient list. Generally speaking, all foods are required to be sorted according to the size of the ingredients used, and you can know how much each ingredient is by looking at the ingredient list. If you do the above two things, you can avoid more than 90% of the "traps".
ScienceThe "three reductions" focus on the kitchenIn the "Healthy China 2030" planning outline, the goal of "salt reduction, oil reduction, and sugar reduction" is clearly proposed: by 2030, the per capita daily salt intake will not exceed 5 grams, the daily edible oil intake will not exceed 25 30 grams, and the per capita daily added sugar intake will not exceed 25 grams. In fact, the scientific "reduction of salt, oil and sugar" can start from the kitchen.
Eating more salt can increase blood pressure, increase the risk of stroke and heart disease, induce stomach cancer and chronic kidney disease, and increase the risk of osteoporosis. According to statistics, although after years of publicity, the salt intake of Chinese residents is still close to 10 grams per day, which is equivalent to a person eating about 11 bags of salt in a year, and there is still a gap between not exceeding 5 grams per day.
Salt intake of Chinese residents.
Eating too much oil can lead to overweight, obesity, and also increase blood pressure, blood lipids and cholesterol, and also induce cardiovascular disease. In 2015, China's per capita daily intake of cooking oil was 432 grams, and in 2022 it has already reached 628 grams or so, while the healthy recommended amount is 25 grams.
The biggest harm of eating too much sugar is that it can lead to tooth decay, tooth decay, overweight and obesity. However, it is a misconception that eating too much sugar can cause diabetes, and the root cause of diabetes is a problem with the person's insulin secretion.
Judging from the monitoring of chronic diseases in China, in 2000, the rate of overweight and obesity in China increased, and some chronic diseases increased from 7% in the 80s of the 20th century to 27% now. The prevalence of diabetes has increased from 2 per cent in 2002 to 12 per cent now, an increase of about 10 per cent. This is also one of the important reasons why China proposes to "three reductions".
Why is it said that the scientific "three minus" focus on the kitchen?Judging from the food survey data in China, the vast majority of our oil, salt and sugar intake comes from the kitchen. 78% of salt intake comes from table salt and condiments, which are put in the kitchen when cooking and stir-frying. It is said that Chinese cook deliciously, a large part of the reason is that there is too much salt, and some of the next meals are small pickles, and the salt content is very high.
The contribution rate of total dietary sodium intake (%) and sodium intake of salt and condiments (%) of Chinese residents
In 2015, China's per capita daily intake of edible oil was 432 grams, of which 477% is vegetable oil, 57% is animal oil, that is, some people will put a little lard or butter when cooking. Together, the fat intake is 534% is cooking oil for stir-frying at home.
The first sugar intake of Chinese residents is the sugar that is eaten directly. For example, the sugar added when making braised pork, the sugar added when drinking soy milk, or the sugar added to make tea and other drinks and tomatoes made by yourself, accounts for about 282%。The second place is sugary dairy products, such as some yogurts that contain a lot of sugar.
Sugar intake of Chinese residents 282% from the kitchen.
Usually cooking at home, how to better "three reductions"?First of all, it is recommended that everyone consume no more than 5 grams per person per day. It is best to buy a salt spoon with a salt amount, and develop the habit of using a salt spoon when stir-frying. When stir-frying, wait until it is almost out of the pan before adding salt. Usually eat less foods with high salt content, such as small pickles, side dishes, etc. If you feel that the taste is too light, you can eat more fresh vegetables and fruits, and put some big ingredients when cooking to add a little flavor to the food.
Low-sodium salt can be used when using salt on a regular basis, especially for the elderly or members of the family with high blood pressure. Low sodium salts contain a little less sodium and help reduce sodium intake. There are also some low-sodium soy sauces on the market, which can also be bought and used to control sodium intake.
MSG and chicken essence also contain salt, 20% of chicken essence is actually salt, and 20% of MSG is also salt. If you put chicken essence and monosodium glutamate in the stir-fry, then put less salt.
In addition to cooking at home, many people also buy some food. There are some pre-packaged foods, when you buy them, you should look at the nutrition label, choose a relatively low sodium content, and control salt intake.
When choosing to buy food, you should also pay attention to the "salt of **". For example, soda biscuits contain about 1 gram of salt per 100 gramsTomato sauce also contains salt, and there is 1 gram of salt in three packets;There is 1 gram of salt in a ham sausage;20 chips also have 1 gram of salt.
Oil control should ensure that the daily intake of edible oil does not exceed 25 grams per person. The first and most effective way is to buy a graduated oil pot at home to control the amount of oil used. The second is to eat less fried foods, such as sugar pancakes, fried dough sticks, fried dumplings and other foods. It is recommended to use more cooking methods such as steaming, boiling, baching and cold dressing, and less frying;Pay special attention to the fact that there may be more oil slick in the vegetable soup or soup, drink less or skim the oil before drinking.
How to control sugar?In fact, many traditional dishes contain a lot of sugar, such as sweet and sour pork ribs, braised pork, shredded sweet potato, pot wrapped meat, etc., so it is not suitable to eat frequently. Sugary drinks, cakes, and biscuits should also be eaten sparingly.
When cooking at home, you should consciously control the use of sugar, try not to prepare sugar, and add little or no sugar when stir-frying, cooking porridge, coffee or soy milk. In addition, you can use fruit to bring a sweet flavor to your dishes, such as adding sweet fruits to your dishesPay attention to the "** sugar" in the kitchen, such as tomato sauce, salad dressing, sweet pasta dressing, jam and other sugary sauces.
Pay attention to the "** sugar" in the kitchen, such as ketchup, which contains sugar.
Rumors at the dinner tableThere are often some rumors at the dinner table, and everyone has heard it more or less.
The first myth is that "bitter melon can fight cancer and lower blood sugar". In fact, bitter gourd tastes bitter because it contains bitter alkali. Picricine cannot lower blood sugar, let alone fight cancer, so you must follow the doctor's instructions to take hypoglycemic drugs to lower blood sugar.
The second myth is that "onions and wine lower blood pressure". In fact, there is also alcohol in red wine, and alcohol can raise blood pressure. Patients with high blood pressure can lower their blood pressure by taking medicine or infusion, and blindly trying other methods may delay the disease, leading to stroke, heart attack, etc.
The third myth is that "chili pepper soaked in liquor cures rheumatoid arthritis". In fact, liquor has a high degree and alcohol is not conducive to arthritis.
The fourth myth is that "children can drink more soup to replenish their nutrition". In fact, the nutrition of the soup is mainly in the meat, and the soup has a lot of oil and salt, and it is easy to produce purines if it is boiled for too long, which is not beneficial to the body.
The fifth myth is that "drinking weak alkaline water can fight cancer". In fact, most of the water we drink is acidic, and 40% of mineral water has a pH of 7Below 0, it is acidic, neutral and alkaline mineral water accounts for 30%, and drinking water has little effect on the pH of the human body.
The sixth myth is that "brown sugar water has a good effect on blood replenishment". In fact, brown sugar water does not have a direct blood tonic effect, its iron content is very small, compared with the iron in lean meat, its absorption rate is also very low, and it is not helpful for blood replenishment. The most effective way to replenish your blood is to eat more lean meats and eat more fresh vegetables and fruits. Fresh vegetables and fruits contain a lot of vitamin C, which promotes iron absorption.
The seventh myth is that "overnight dishes cause cancer". In fact, there is nothing wrong with the overnight itself, but the way to put it is wrong. The correct way to do it is "refrigerator + crisper box", which can inhibit the growth of bacteria and prevent the production of nitrite.
The eighth myth is that "vinegar soaked eggs can soften blood vessels". Vinegar soaked eggs can dissolve calcium acetate, which not only tastes bad, but also has a bad calcium supplementation effect, and cannot soften blood vessels. Moreover, eggs are easy to carry salmonella and should not be eaten raw. Vascular aging can only be delayed, not reversed.
The ninth myth is that "meat, eggs, and milk are the root causes of modern geriatric diseases". In fact, meat, eggs, and milk are important for the body's essential iron, zinc, calcium, vitamin B12 and protein**. If a vegetarian diet is not well balanced, there is a risk of nutrient deficiencies and can easily lead to malnutrition. Eating the right diet is the key to a healthy diet.
The tenth myth is that "the more calcium, the better". In fact, the body can't absorb too much calcium, and if the dose is too high, the absorption rate will decrease. The absorption rate of the supplement is highest at 500 mg. If too much calcium is supplemented, it can lead to muscle relaxation, constipation, nausea and other discomforts, and can also interfere with the absorption of zinc and iron, resulting in zinc and iron deficiency. Severe excessive calcium intake can also cause hypercalcemia, hypercalciuria, kidney stones, vascular calcification, and even kidney failure. People with normal stomach function can achieve the purpose of calcium supplementation by eating ordinary calcium tablets.
This issue**, from the 825th Capital Science Lecture Hall).
Disseminate scientific knowledge and promote the spirit of science.
Let the popularization of science and scientific and technological innovation fly together.