People’s Daily Online, Beijing, August 1st (Zhao Zhuqing) "O-type blood attracts mosquitoes especially", "Too much beer will lead to a beer belly" and "Eating out-of-season fruits and vegetables is harmful to health" … With the arrival of midsummer, all kinds of "legends" about summer began to be "hot" on the Internet. A few days ago, the Beijing Science and Technology Journalists Editors Association and the Beijing regional website jointly released the "July Science Rumors List" to expose the true face of these rumors one by one.
1. Is the "beer belly" really drunk by drinking beer?
Myth: Many people say that beer belly is definitely related to beer, because beer is "liquid bread", and drinking too much will cause beer belly.
Truth: Beer belly is a figurative term. The real cause is unreasonable eating habits, and beer with the same weight is far less calorie-rich than bread.
The real beer belly is a lot of fat accumulated on the belly, and the accumulation of fat comes from excessive energy. Even female comrades who don’t drink beer and accumulate more body fat will have a very fat abdomen.
Li Hong, a professor-level senior engineer in the Brewing Engineering Development Department of China Food Fermentation Industry Research Institute, said: "The excess energy comes from two aspects. The first is too much energy intake, and the second is too little energy consumption. After excess energy exists in the form of fat, it is easy to accumulate in the abdomen. So, does it have anything to do with beer? It should be said that there is no direct and inevitable relationship, but what is really relevant is the way and lifestyle of consuming food. "
A study by the German Federal Institute of Nutrition Medicine shows that "beer belly" is related to male genes, just like female obesity starts from the buttocks, and most of male fat is stored in the abdomen. The researchers found that beer drinkers are not more likely to have a beer belly or even obesity than those who don’t drink beer. Although beer is not a diet drink, it is not the cause of overweight. If factors such as exercise and education are excluded, people who often drink beer will not have thicker waistlines and heavier weights than those who don’t drink or rarely drink.
2. Type O blood attracts mosquitoes most?
Myth: When summer comes, mosquito bites make many people miserable. Many rumors say that type O blood is sweet and fragrant, so type O blood is especially attractive to mosquitoes.
Truth: Mosquitoes mainly rely on carbon dioxide, heat, volatile chemicals and other factors to detect and locate targets. It can distinguish some molecules produced by human cell activities. As long as you are breathing, sweating or emitting heat, your temperature, the water vapor and carbon dioxide you release, and the chemicals in your sweat, such as acetone, octenol and lactic acid, are tempting mosquitoes to follow the trail to find you.
So is there any relationship between blood type and mosquitoes? Scientists and media from all over the world have done a lot of experiments, and the current conclusion proves that there is no direct relationship.
As for the saying that "blood is sweeter than mosquitoes", according to the current research conclusions, there is no direct connection between these two points. If you want to find the correlation from the blood test report, you may wish to pay attention to the routine examination of the physical examination report. There is an item called "eosinophils" in the column of blood test, and those who are higher in this item are better for mosquitoes.
3. Is there really a "watermelon injection"?
Rumor: A friend in Daxing told me that now melon farmers are spraying pesticides on watermelons, growing fast and selling money, and grafting on pumpkin seedlings, and they never eat them themselves! "Injection watermelon" is injected with banned food additives-sodium cyclamate and carmine! It may damage the liver and kidneys and affect children’s intellectual development! The watermelon pulp that has been injected is red and the juice is "rich".
Truth: In response to rumors, Shenzhen Inspection and Quarantine Bureau conducted a surprise inspection on six watermelon enterprises and processing plants in its jurisdiction, and none of them detected saccharin sodium, artificial color and mercurochrome (mercury bromide red). Some experts even conducted injection experiments, and the results showed that the color of watermelon pulp after injection was uneven, and because the pinhole was easy to be infected with bacteria, watermelon was perishable, which was not conducive to sales.
As for injecting sodium cyclamate and carmine, the reason is similar. According to botanical principles, plants can only absorb water and nutrients in living conditions, and they need to be organized by means of plant transportation system. However, the vascular bundles of melon seedlings are very small, and it is hard to imagine that they want to inject liquid. Even if the injection is successful, it must be absorbed and transformed by the plant itself to make it sweet. However, these two substances cannot be absorbed normally by the melon seedlings.
Moreover, after the injection, the pinhole on the watermelon is obvious, the juice will overflow from the pinhole, and the color of the pulp at the injection site will also deepen. These phenomena are very obvious, and it is easy for merchants to be seen through if they really do this.
No matter during the growth or after the harvest of watermelon, it is impossible to absorb the liquid substance by injecting it into the watermelon fruit. Only through vascular tissue can plants absorb water and nutrients and inject them into fruits forcibly, and the injected substances will accumulate in tiny tissues and destroy the tissue characteristics of watermelon pulp, which can never be like that in Weibo: red watermelon pulp and rich juice. This is also proved by experiments. No matter the size of the pinhole, the outer ring of the pinhole will begin to blacken after two or three hours of storage of the injected watermelon, which is easy to find. How can anyone do such a thankless thing if it is put out and no one cares about it?
4. Is it necessary to sweat in summer?
Rumor: "Practicing for 39 days in winter and three days in summer" is the spoken language of many middle-aged and elderly people’s sports, especially in the dog days, and middle-aged and elderly people who are sweating can be seen everywhere on the avenue and in the park. They said that many health reminders said: "It is only comfortable to sweat thoroughly, and the fitness effect can be achieved."
Truth: Experts remind that fitness should not blindly pursue sports pleasure, especially in the summer when sweating and consumption are high, bodybuilders should pay more attention to the degree of exercise to avoid excessive consumption and damage to some functions of people.
Sweat properly in summer, but you don’t need to exercise until you sweat profusely. In fact, it is easy to cause dehydration. At the same time, people’s body temperature rises obviously after summer exercise, and with the influence of high temperature weather, they are prone to heatstroke. Therefore, most people should avoid extreme exercise and anaerobic exercise, and it is best to use aerobic uniform exercise, and the heart rate should be controlled in a small exercise area, that is, about 120 times/minute. Middle-aged and elderly people should be slower, because if they exercise excessively in midsummer, sweating will lead to thick blood. Coupled with the hot weather, it is likely that they will not be healthy, but will lead to heart disease and cerebral infarction.
Exercise in the sun for a long time in summer will aggravate the disorder of water and salt metabolism in the body. Therefore, you should drink some light salt water or sports drinks before, during and after exercise, about 50 ~ 100 ml every half hour.
In addition, summer exercise is more suitable to choose morning or evening, and the location is chosen in a place with shade. The duration of exercise should not be too long, and it should be 30 minutes to 1 hour, which can be adjusted according to personal physique and exercise intensity.
5. Will the baby die if he eats salt?
Rumor: Recently, it was reported that "a mother listened to her neighbor’s advice and added salt to her porridge, but she didn’t expect to ruin her eight-month-old child’s life."
Truth: Salt is essential for everyone. For infants, less salt is the general principle.
One of the reasons why we need less salt is because of physiological limitations. The salt in the human body is mainly metabolized by the kidney, more than 90% enters the urine, and the rest is excreted through sweat. Because the development of infants’ kidneys is not complete, excessive salt intake is likely to increase the burden on the kidneys, lead to abnormal metabolism, and cause edema. Of course, it’s impossible to be so exaggerated to die immediately.
The main reason for the lack of salt is long-term consideration. The occurrence of hypertension is closely related to high-salt diet, and in order to reduce the salt intake of adults, we must start from controlling the taste of infants. Infant’s taste system is still in the developing process, and it is very sensitive to condiments. Too much salt may not only affect their eating habits in the long run, but also cause refusal to eat.
That is to say, it’s not "babies can’t eat salt within one year old", but following the general principle of less salt, it’s not necessary to add extra salt to babies, but also to keep your eyes open, pay attention to the formula table of complementary food, and rationally allocate baby’s recipes.
6. margarine equals trans fatty acids?
Myth: Margarine is mainly extracted from edible oils and fats, so margarine contains more oils and fats, especially trans fatty acids. Eating a lot of trans fatty acids will affect people’s memory, and for teenagers, it will affect the development of the central nervous system. Long-term excessive accumulation of trans fatty acids can also induce serious diseases such as asthma, tumor and diabetes.
Truth: The statement that "trans fatty acids have health risks" has been widely circulated. Recently, China Food Rumor Alliance and China Baked Food and Sugar Products Industry Association publicly refuted this rumor. The Food Rumor Alliance stated that raw materials of baked goods such as margarine and hydrogenated vegetable oil are not equal to trans fatty acids, and the argument that trans fatty acids cause obesity and diabetes is still inconclusive.
According to Zhu Nianlin, chairman of China Baked Food and Sugar Products Industry Association, trans fatty acids have always been regarded as "time bombs on the table", and raw materials in baked goods-margarine, hydrogenated vegetable oil, non-dairy creamer, shortening and cocoa butter substitute are often labeled as trans fatty acids, which has caused adverse effects on the industry.
Professor Cao Yanping from the College of Food Science of Beijing Technology and Business University said that with the development of technology, the trans fatty acid content in oil has dropped to a very low level. If consumers need it, they can completely remove trans fatty acids, but it will affect the taste of food.
According to Kai Zhong, deputy director of Kexin Food and Nutrition Information Exchange Center, in addition to processed foods, trans fats are widely found in natural foods such as beef, mutton, fat and milk. According to the report of China Residents’ Dietary Intake Level of Trans Fatty Acids and Its Risk Assessment by the National Food Safety Risk Assessment Center in 2013, the average daily intake of trans fats in China is 0.39 grams, and the energy supply ratio is 0.16%, which is far lower than the recommended value of the World Health Organization (less than 1%).
However, in order to control the intake of trans fatty acids, the Food Rumor Alliance suggests that consumers should pay more attention to the nutrient list on the label when buying packaged foods, and they can choose foods that do not contain trans fatty acids or have low content, especially those for infants and young children. In addition, it is necessary to control the amount of vegetable oil used in cooking, not to consume a large amount of animal fat to avoid trans fatty acids, and to avoid excessive oil temperature and repeated frying.
7. Do soy products induce breast cancer?
Myth: The disorder of breast structure caused by the absolute or relative increase of estrogen level and the decrease of progesterone level can induce lobular hyperplasia of breast, while the phytochemicals contained in soybean and bean products, such as soybean isoflavones, are known as "phytoestrogens", so bean products will aggravate mammary hyperplasia and even induce breast cancer.
Truth: Soybean isoflavone in soybean is a phytoestrogen, and many people worry that it will induce breast cancer.
In fact, phytoestrogens are different from human estrogens. It is found that phytoestrogens play a two-way role in regulating estrogen levels in women.
Studies have shown that eating soy products will not only cause breast cancer, but also reduce its risk.
8. Eating out-of-season fruits and vegetables is harmful to health?
Myth: A post about "out-of-season fruit and vegetable hazards" is widely circulated on the Internet. This post states categorically that the planting process of out-of-season fruits and vegetables is not as safe as it seems. In order to achieve high and stable yield, farmers often overuse highly toxic pesticides and ripening hormones.
Truth: Many people will say that out-of-season fruits are poisonous and inedible because they use a lot of chemicals such as pesticides. In fact, even seasonal fruits will use pesticides in the planting process. It is normal to have pesticide residues, and "existence" does not mean "exceeding the standard" or "excessive", nor does it mean that eating out-of-season fruits will do harm to the body. Moreover, as long as the general fruit is planted in a standardized way, the pesticide residue does not exceed the standard, and normal consumption will not cause harm to human health.
There is also a saying that out-of-season fruits need to be "promoted" by plant hormones, which will make people precocious. In fact, whether it is out-of-season fruit or in-season fruit, a certain amount of plant growth regulators, that is, plant hormones, are used in the modern planting process. In addition, all fruits naturally contain a certain amount of phytohormones. However, the efficacy of plant hormones is generally very low, and they are different from the molecular structure and mechanism of action of human hormones, and will not have adverse effects on the human body. It is only unfounded to worry about precocious human nature. In addition, plant hormones have strong self-limitation, and farmers will not add more in the normal planting process, otherwise it will be counterproductive.
There is another worry about out-of-season fruits, that is, they are considered to have poor nutrition.
The nutritional value of out-of-season fruits may indeed be different from that of in-season fruits. However, these differences do not mean that they are not nutritious, let alone harmful. Considering that in the cold winter, if there is no fruit to eat, human health may be more affected. From the perspective of nutrition supply, eating fruit is much better than not eating. For example, eating grapes out of season in winter is far better than "no grapes to eat".
Generally speaking, there is nothing wrong with out-of-season fruits and vegetables. Compared with winter without fruits and vegetables, out-of-season fruits are still very helpful for people to obtain and supplement nutrients, especially vitamins and minerals.
9. "Don’t eat after noon" helps to lose weight?
Myth: "Don’t eat after noon" probably means that you don’t eat after noon (from 11: 00 noon to 1: 00 pm) until dawn the next day. In the minds of many dieters, "no food after noon" is regarded as "a good way to lose weight". Some people even regard it as a "secret method of health preservation" and insist on it for many years.
Truth: If people are on an empty stomach for a long time, then the body will have some abnormal reactions-the contents of two hormones that regulate weight will deviate greatly from the normal value:
Brain-gut peptides that can increase appetite, stimulate hunger, accelerate gastric emptying and gastric acid secretion will increase rapidly; Leptin, which can reduce appetite and inhibit the synthesis of fat cells, will be greatly reduced. If so, people will not lose weight after lunch, but will gain weight more easily.
Eating the right dinner is more helpful to health than not eating it. It is best to have dinner between 5: 00 and 7: 00, and try to keep it regular; Dinner should be light, and you can eat some lean meat or eggs with short muscle fiber and easy digestion. Eat more vegetables and coarse grains.
Compared with the ancients, modern people have a large amount of activities at night, and often go to bed in the early hours of the morning. If they don’t eat dinner or even stop eating, they will lack energy, and there is gastric acid in the human stomach. If they don’t eat for a long time, it may cause gastric acid to damage the gastric mucosa, and diseases such as ulcers will appear over time. If the ulcer is not found in time, it is likely that more serious diseases such as gastrointestinal bleeding and ulcer perforation will occur.
"No food after noon" is not suitable for everyone. Only by grasping the rhythm and habits of eating carefully can we realize our pursuit of good figure under the premise of health. Eat after noon, and eat with high quality. This is the correct way to keep in good health.
