Will donating blood make people "weak"? Is an elevated tumor marker cancer? The June 2024 "Science" Rumor List was recently released. The monthly "science" rumor list is guided by the Beijing Association for Science and Technology, the Cyberspace Administration of the Beijing Municipal Party Committee, and the Capital Internet Society, and jointly released by the Beijing Science and Technology Reporters and Editors Association and the Beijing regional website joint rumor refutation platform, and is supported by the Science and Technology Reporters and Editors Professional Committee of the China Science Writers Association, the China Evening News Science Editors and Journalists Association, the Shanghai Science and Technology Communication Association, and the Institute of Science and Technology Information of the Beijing Academy of Science and Technology.
1. Can I take antipyretic medicine to cool down after heat stroke?
Rumors:
Heat stroke is the same as fever caused by a bacterial or viral infection, as long as you take antipyretic medicine to cool down.
The truth:
The body's internal body temperature is regulated by the hypothalamus in the brain. The hypothalamus examines our current body temperature and compares it to a normal body temperature of about 37°C. When body temperature is low, the hypothalamus promotes heat production and retention; Conversely, when the body temperature is on the high side, it is cooled by dissipating heat or sweating. The fever caused by heat stroke is because there is a problem with the body's heat dissipation center, which cannot dissipate heat through sweating, and taking antipyretic drugs cannot restore the heat dissipation center to normal, but will backfire, aggravate the symptoms, and cause heat stroke. Therefore, physical cooling, such as moving the person to a cool or air-conditioned room, should be preferred after heat stroke, rather than taking fever-reducing medications.
2. "Black technology" sunscreen clothing, not only sunscreen, but also moisturizing, cooling and mosquito repellent?
Rumors:
Recently, a variety of "black technology" sunscreen clothing has appeared on the market, such as "mask sunscreen clothing", which advertises that hyaluronic acid is added to the product, which can achieve moisturizing effect in contact with the skin; "Xylitol sunscreen clothing" claims to be able to reduce the body temperature by 5 °C after wearing; There is also a "mosquito repellent sunscreen clothing" with wormwood ingredients, which claims to have multiple effects such as mosquito repellent and antibacterial.
The truth:
Recently, "hyaluronic acid mask sunscreen clothing", "xylitol cooling sunscreen clothing", "wormwood mosquito repellent sunscreen clothing" and other "black technology" products on the market, although the idea is very good, but in fact, the gimmick is far greater than the reality.
The proportion of hyaluronic acid added in hyaluronic acid sunscreen clothing is very low, which is far from the concentration of hyaluronic acid used in the medical beauty industry; Xylitol sunscreen clothing only has a cool feeling at the beginning of wearing, and it is no different from ordinary sunscreen clothing for a long time; Mosquito repellent sunscreen clothing has a general mosquito repellent effect, and ordinary clothing can also play a role in shielding mosquito bites to a certain extent.
The national standard stipulates that only when the UPF (i.e., ultraviolet protection factor) of the product is greater than 40 and the UVA (long-wave ultraviolet ray) transmittance is less than 5%, it can be called "ultraviolet protection product". In general, the higher the UPF value, the better the protection against UV rays. Therefore, consumers can verify the protective effect of sunscreen clothing before purchasing.
In addition to sun protection, consumers should also pay attention to the material of sunscreen clothing. From the perspective of materials, the sunscreen effect of products made of polyester and nylon is better than that of cotton and silk; In terms of color, bright or dark colors have better sun protection than light colors; From the point of view of performance, it is easier to wear for a long time with good washing resistance, and more comfortable with high air permeability and moisture permeability.
3. Is it more energy-efficient to turn the air conditioner on and off for a while?
Rumors:
Turn on the air conditioner first, turn it off when the room is cool, and turn it on again when it is hot, so that the cycle can greatly shorten the refrigeration working time of the air conditioner and save electricity.
The truth:
The air conditioner is turned on and off frequently, which consumes more electricity. This is because while the air conditioner does not consume energy when it is not working, the energy consumption during the start-up phase is high. If you restart too many times, the total energy consumption will exceed the energy consumption of the air conditioner all the time. Of course, when the air conditioner is turned off at a long enough interval, its overall power consumption will definitely be less. However, if the shutdown interval is too long, the human body will feel uncomfortable, and if you want the human body to be comfortable, you must shorten the interval between the shutdown of the air conditioner. Under this premise, the power consumption of the air conditioner on and off will generally be greater.
Narrowing the gap between indoor and outdoor temperatures, and minimizing heat exchange between indoor and outdoor temperatures, is the most effective way to save electricity.
When cooling in summer, the indoor temperature should not be set too far from the outdoor temperature, 26 °C is a more reasonable temperature, which can minimize the temperature difference with the outdoors under the premise of ensuring human comfort, and the same is true in winter. One of the key reasons why the dehumidification function saves electricity is that the temperature difference is small. In addition to the heat exchange between the air conditioner and the outside air, other forms of heat exchange should be eliminated as much as possible. Blackout curtains and door curtains can effectively prevent some heat exchange.
In addition, there are several ways to save power:
1. When the air conditioner is not in use, the power is completely cut off, and the power can also be saved. Because any electrical appliance, as long as it is energized, it is in standby mode and is constantly consuming power.
2. After the air conditioner enters sleep mode, it will automatically increase the preset temperature, which will also reduce the temperature difference between indoor and outdoor and reduce energy consumption.
3. Inverter air conditioners are more energy-efficient than traditional fixed-frequency air conditioners. Because in the process of working, the inverter air conditioner takes the preset temperature as the judgment standard, and compares it with the measured temperature of the sensor to adjust the working speed of the compressor. When the temperature difference is large, it runs at full load, and when the temperature difference is small, it runs at low speed, so as to avoid the additional energy consumption caused by shutdown and restart.
4. The better and more fit a person is, the more likely is he to suffer from heat stroke?
Rumors:
People with better physique are more likely to suffer from heat stroke, because people with better physique are better at adapting to the environment, and once they adapt to hot weather, they are prone to turning a blind eye to the danger, which makes it easier to cause heat stroke.
The truth:
"The better the physique, the more likely it is to suffer from heat stroke" is incorrect, and a more appropriate description would be "Almost everyone is at risk of heat stroke, and people with good physique are no exception". The professional name of heat stroke is "heat stroke", which can be divided into classic heat stroke (non-exertional heat stroke) and exertional heat stroke, the former is more likely to occur in the elderly and weak groups, and the latter is prone to the able-bodied people who work in high temperature environments.
Classic heat stroke, also known as non-exertional heat stroke, is a severe symptom of heat stroke that occurs when anyone is exposed to high temperatures. The cause of this type of heat stroke can be simply understood as "lying down" - as long as you are exposed to high temperatures, you can experience severe heat stroke symptoms even when you are resting. As a result, classic heat stroke tends to occur in children, pregnant women, the elderly, the elderly, those with chronic underlying medical conditions, and immunocompromised individuals.
The other is exertional heat stroke, which is different from "lying down", this type of heat stroke is not only exposed to high temperature and humidity, but also usually requires people to do strenuous exercise or labor, and the typical population is athletes, new recruits who have just started training, construction workers and food delivery boys, who look like young and middle-aged people who are strong at a glance. Of course, for the frail people, they will be recruited even if they don't even need to work. In other words, regardless of physical fitness, there is a risk of exertional heat stroke.
Survey data show that the frail and sick people who stay at home for a long time are the main group of people with heat stroke, and the mortality rate after the onset is much higher, such as elderly patients are prone to hypertension, diabetes, coronary heart disease and other underlying diseases, and use a variety of drugs at the same time, which are risk factors for increasing the risk of heat stroke and mortality.
5. Will donating blood make people "empty"?
Rumors:
Donating blood can make people "weak", leading to a decrease in the body's immunity, which is not good for health.
The truth:
Appropriate blood donation is not harmful to health, which has been proven by millions of blood donors around the world. The human bone marrow has a strong compensatory function, and the hematopoietic function of the bone marrow can be increased to 6-8 times the usual amount under the stimulation of blood loss. In general, water and inorganics lost in a single blood donation return to normal levels within 1-2 hours; Plasma proteins synthesized by the liver can be replenished within 1-2 days; Platelets take 2-3 days, while red blood cells and hemoglobin can return to pre-donation levels in 7-10 days. Donating blood under suitable conditions can also make the body's hematopoietic function more active, continuously produce new hematopoietic cells, and promote metabolism.
There are also no studies showing that donating blood in moderation can lead to a decrease in human immunity. In the process of blood donation, some white blood cells and some immune-related lymphocytes are indeed lost, but from the perspective of blood donation, after a healthy adult donates 200ml to 400ml of blood at a time, the number of white blood cells lost is very small, accounting for only 1% to 2% of the total number of white blood cells in the human body, and the white blood cells lost can usually be replenished from the bone marrow in about 2 hours. In fact, healthy people have a strong blood regeneration function and a strong ability to self-regulate. Blood donation stimulates the body's hematopoietic function, accelerates the production of blood cells, and promotes blood metabolism to meet the needs of the body. Therefore, donating blood in moderation will not significantly affect our immunity.
6. Is it faster to lose weight by eating only vegetables?
Rumors:
If you want to lose weight faster and more effectively, just eat vegetables.
The truth:
While eating only vegetables may help reduce calorie intake and thus weight loss in the short term, this approach is not healthy in the long run.
Eating only vegetables for a long time will cause insufficient intake of essential nutrients such as energy, protein, fatty acids, fat-soluble vitamins, vitamin B12, iron, zinc, etc., which will lead to decreased basal metabolism, muscle loss, anemia, decreased immune function, endocrine disorders and other problems.
The best strategy to lose weight is to maintain a healthy lifestyle by eating a balanced diet and exercising properly. It is recommended to include a variety of foods in the diet, such as vegetables, fruits, whole grains, lean meats, poultry, fish and shrimp, eggs, legumes and their products, and nuts to ensure a complete nutritional intake, small portions, and control of food and calories.
7. If you eat too many soy products, will it cause gout or cancer?
Rumors:
If you eat too many soy products, it will not only cause gout due to the increase in uric acid, but also lead to cancer.
The truth:
Soybeans are indeed high-purine foods, with 100 grams of soybeans containing 218 mg of purines and 100 grams of black beans containing 170 mg. But generally we rarely eat soybeans directly, usually squeezed into soy milk, made into tofu, dried tofu and other soy products, or cooked and eaten. The purine content of soy products under different processing states varies greatly.
After soybeans are milled, soaked, diluted with water and other processing procedures, the purine content of soybean products is significantly reduced, for example, the purine content of 100 grams of tofu (north) is only 68 mg, which is a low-purine food. Therefore, except for yuba and bean skin, which are high-purine foods, the purine content of other soy products is not high.
Gout patients should control the intake of dried soy products with high purine content, and for ordinary concentrations of soy milk, tofu, and dried beans, they can be ingested in small amounts without worrying too much. The intake of high-quality protein in the acute stage should be mainly eggs and milk, and it is not recommended to consume soybeans and soy products.
In addition, soy products contain a substance called isoflavones, which are a class of phytoestrogens existing in plants in nature, and it is precisely because of this "estrogen" that soy products are saddled with a black pot of "carcinogenic". In fact, isoflavones only have weak estrogenic activity, and although they can bind to the body's estrogen receptors, the force is much weaker than the estrogen produced by the body itself.
In fact, the estrogen-like effect of soy isoflavones can play a two-way role in regulating estrogen levels in the body. When the human estrogen content is insufficient, isoflavones and estrogen receptors combine to supplement estrogen; When the human estrogen level is too high, soy isoflavones can prevent estrogen from binding to its receptors and play an inhibiting role, which is equivalent to reducing estrogen levels. For most people, eating soy in moderation may be beneficial in preventing some type of cancer.
8. The shorter the shelf life of food, the safer?
Rumors:
The shelf life of food is long and short, and the shorter the shelf life, the fresher and safer it is.
The truth:
This is a misconception. The length of the shelf life is not directly related to the quality of the food, how long the food can be stored is closely related to its own properties and production process, in addition to the microbiological, physical and chemical properties of the food, as well as the packaging materials and packaging methods, processing environmental conditions, the expected consumption mode and other factors.
For example, freshly packed rice dumplings need to be eaten as soon as possible, and the shelf life is mostly only 3-5 days; The shelf life of vacuum-packed zongzi can be extended to 3-6 months, while the shelf life of frozen zongzi can reach more than 12 months.
Another widespread misconception is that "the long shelf life of food is due to the addition of a large number of food additives". In fact, the length of shelf life is not necessarily related to food additives. The use of food additives is to improve or maintain the nutritional value and flavor of the food itself, and to improve the quality and stability of the food. At the same time, it is also convenient for the production, processing, packaging, transportation and storage of food. The two basic elements of food additives are safety and necessity, as long as they are within the legal range of type and dosage, they will not harm the health of consumers.
9. The whiter the teeth, the better?
Rumors:
Teeth are originally white, so the whiter the teeth, the healthier and more aesthetically pleasing.
The truth:
Healthy teeth are not pure white, but a natural, shiny, uniform yellowish color. The color of the tooth is mainly determined by the structure of the crown. The outermost layer of the crown is the enamel, which is the hardest part of the tooth, and the higher the degree of mineralization, the more transparent it is; The inner layer of enamel is pale yellow dentin. Therefore, when the degree of enamel mineralization is high, the yellowish color of dentin is exposed; When mineralization is low, the enamel transparency decreases and the teeth appear whiter.
Attentive parents will find that after the child is replaced with baby teeth to permanent teeth, the teeth become less white. This is because permanent teeth have a higher degree of enamel mineralization than baby teeth, so the yellowish color of dentin is more pronounced, giving the teeth a pearly white or yellowish appearance. As we age, our teeth will naturally turn yellow due to changes in the composition of our tooth enamel, just like our skin color and eyes. Of course, in real life, in addition to the natural degree of mineralization, there are many external factors that affect the color of teeth, such as smoking, drinking tea, drinking coffee, and other habits that cause teeth to color, making teeth yellow or pigmented. Have regular dental check-ups and good oral hygiene habits to have healthy and beautiful teeth.
10. Is an elevated tumor marker cancer?
Rumors:
Elevated tumor markers indicate cancer.
The truth:
Tumor markers play a very important role in the diagnosis and treatment of tumors, and can be roughly divided into two categories. One is the substances that exist in tumor cells or on the surface of cell membranes, and are expressed by tumor cells and secreted into blood, other body fluids and tissues. The other type is substances released by the body in response to tumors.
Tumor marker detection can be used in the following aspects: Early warning: Tumor marker detection can show abnormalities in the early stage of the tumor, which can precede X-ray, ultrasound, CT and other imaging examinations, providing the possibility for early detection of tumors. Adjunct diagnosis: Tumor marker testing helps doctors determine the presence and type of tumor. Monitoring efficacy: During treatment, tumor marker testing can be used to evaluate the treatment effect and determine whether the tumor has recurrence, metastasis, etc.
Elevated tumor markers do not mean that 100% of people have cancer. First, the tumor marker reference interval includes the level of 95% of healthy people, which means that 5% of healthy people may also have elevated tumor marker test results. Second, most of the classical tumor marker assays are immunological methods, and there are non-specific reactions, so there is a possibility of false elevation. Finally, although the vast majority of tumor markers are found in malignant tumors, tumor markers may also be detected in benign tumors and normal tissues. For example, daily alcohol consumption, taking certain medications, and the presence of inflammation may cause a spike in tumor markers.
To sum up, if you get a report of elevated tumor markers, don't be too nervous, but pay full attention to it. The correct way is to seek the help of a doctor, ask the doctor to give a personalized diagnosis and treatment plan through the dynamic monitoring of tumor markers, based on medical history, family history, lifestyle habits, physical examination and other auxiliary examinations.
Source: Guangming.com