December 2024 "Science" Rumors List: Is standing office healthier than sitting office? Fruits should not be heated before eating?

The list of "science" rumors in December 2024 is revealed! Let's take a look at the rumors and the truth

1. Standing is healthier than sitting

gossip:

Sitting for long periods of time at work is harmful to your health. Simply changing to standing work can offset the damage.

the truth:

The potential health risks of prolonged sitting at work have been confirmed by the Institute of Medicine. Sitting for a long time can lead to a decrease in metabolic rate, thereby increasing the risk of obesity, type 2 diabetes and cardiovascular disease. Although standing at work can improve some indicators such as blood pressure, insulin sensitivity and triglyceride levels, these improvements may not significantly reduce the risk of cardiovascular disease. Standing desks and similar working postures cannot avoid the health problems caused by long periods of sitting.

In order to achieve the best office health effect, it is recommended to adopt an alternating sitting and standing work mode: for example, using an adjustable height desk, users can flexibly change their posture during work, which helps to reduce the negative effects of sitting or standing for a long time. According to experts, the ideal office mode should include regular posture changes, switching between sitting and standing postures every 30 to 60 minutes, and combined with simple office interval activities such as stretching and short walks, which can further improve overall health and reduce health risks.

To sum up, a reasonable combination of standing and sitting while working and increasing daily activities are effective strategies to stay healthy.

2. "Black technology" new thermal underwear can achieve self-heating

gossip:

On online platforms, sales of "self-heating underwear" are booming. Merchants claim that "black technologies" such as "far infrared" and "graphene" are used in thermal underwear, which is both beautiful, thin and warm, and perfectly solves all the drawbacks of traditional thermal underwear. Even at -40℃, you won't feel cold when wearing it.

the truth:

From the law of conservation of energy, heat cannot be generated out of thin air, so there is no such thing as a truly self-heating fiber. All "self-heating" actually generates heat with the help of external forces. Most of the "self-heating underwear" currently on the market use the principle of fiber moisture absorption and heat generation. The textile industry generally uses a variety of fiber blends to achieve a balance between moisture absorption and heat release and moisture dissipation and dryness, such as blending acrylic fibers and polyester fibers. Labeling this type of blended fiber as a "self-heating" textile is actually a marketing trick used by merchants.

Far-infrared textiles are a highly efficient thermal insulation material. The principle of heat generation is to absorb heat first and then release it. There are two types of energy it absorbs: one is the energy in the environment, such as visible light, infrared, and far-infrared rays in sunlight; the other is the energy emitted by the human body itself. After far-infrared fibers absorb this energy, they convert it into far-infrared rays and radiate them back to the human body, thereby providing heat to the human body. However, far-infrared fibers are expensive, so there are not many real far-infrared textiles on the market.

Similarly, graphene is a nanomaterial with high strength, high electrical conductivity and excellent thermal conductivity. Graphene fibers can be used to make clothing with antibacterial, deodorizing, UV protection and other functions. However, graphene textiles are expensive and require high preparation processes, which makes them difficult to mass produce. Therefore, the autumn clothes and autumn pants on the market that cost around 100 yuan are basically not made with real graphene.

Experts say that thinness and warmth are contradictory. With the current level of technology, many "black technology" textiles cannot achieve the effects claimed by merchants, and the advertising slogans are suspected of exaggeration. At the same time, the tightness of thermal underwear should be moderate, neither too tight nor too loose. Tight design helps maintain body temperature, while too loose may allow cold air to penetrate and affect the warmth effect.

3. Fruits should not be heated before eating

gossip:

Heating fruits will destroy their nutrients, so they should not be heated before consumption.

the truth:

Most fruits do not lose much nutrition after heating, and only a few fruits with high vitamin C content will have their vitamin C destroyed after heating, such as kiwi, tangerine, grapefruit, orange, strawberry, etc. The fruits we often eat, such as apples, pears, bananas, etc., do not have a particularly high vitamin C content, so there is no significant loss after heating.

For example, heating apples before eating is more suitable for the elderly and people with indigestion. Whether boiled, steamed, or baked, the nutrients in apples are not lost much. The potassium and dietary fiber in apples will not be lost due to heating, as they are heat-stable components; the content of polyphenols will even increase slightly under short-term heating conditions; and the pectin in the apple peel will gradually dissolve and be more easily absorbed by the human body; the sugar in the apple will not be destroyed by heating, and may even form a small amount of oligosaccharides due to heating.

After the fruit is heated, the dietary fiber is softened, which can reduce the irritation to the stomach and intestines. It is more suitable for people with weak gastrointestinal function, as well as menstruating women, postpartum women, dental patients, etc. In winter, if you are worried about the fruit being cold, you can soak the fruit slices in hot water, or slightly heat them in the microwave before eating.

4. Cooking oil that turns black during burning is a “problem oil”

gossip:

If cooking oil turns into a black substance similar to asphalt after being overheated, it means that it is adulterated with unsafe substances and is considered "problem oil."

the truth:

All edible oils will undergo a series of fission and polymerization reactions after excessive but incomplete combustion, forming a layer of black gelatinous substance. This is a normal phenomenon and a common property of oils and fats, and is not a food safety issue.

The main component of edible oil is triglyceride, which is composed of glycerol and fatty acids. When edible oil is heated to a certain temperature, triglyceride begins to oxidize and crack, producing some small molecular volatile substances, which are commonly known as oil smoke. Generally speaking, the time point when vegetable oil produces oil smoke, namely the smoke point, is related to the type of edible oil and the degree of refining. The smoke point of refined oil is usually around 200 degrees Celsius.

If the temperature continues to rise to over 300 degrees Celsius, the oil will reach its ignition point and the cooking oil will burn, which means a violent oxidation reaction will occur. Unsaturated fatty acids in oils and fats contain a large number of double bonds (fatty acids are divided into saturated fatty acids and unsaturated fatty acids). While burning and oxidative cracking, polymerization reactions will also occur to form substances with larger molecular weights, which is what netizens call the asphalt-like black colloid at the end. This substance is actually monomer carbon formed when vegetable oil is not burned completely.

If the temperature is raised and heated further, these black colloids can be completely burned, and all carbon dioxide and water are produced. This is the same reason why incomplete combustion of wood will form charcoal and motor vehicles sometimes emit black smoke.

5. When taking multiple medicines at the same time, you must take them at intervals.

gossip:

When taking several medicines at the same time, there must be a period of time between them. If you don't separate the two, the medicines will "fight" in your stomach, affecting their efficacy or even producing toxins.

the truth:

It is a common misconception that elderly people do not need to take multiple medications at intervals.

Many elderly people may take multiple medications half an hour or an hour apart, which may affect the medication time and thus the quality of life. In fact, whether medications need to be taken at intervals should be determined based on the characteristics and interactions of the drugs. For example, some drugs such as levothyroxine and calcium tablets may need to be taken more than two hours apart to avoid mutual effects in the absorption process.

However, for most drugs, if there is no clear interaction data, they can be taken at the same time, and safety is ensured by regularly monitoring the effectiveness of the drugs. Therefore, whether it is necessary to take the drug at intervals should be consulted with a doctor or pharmacist for professional advice, rather than deciding on your own.

6. Band-Aids and Band-Aids are the same thing

gossip:

Band-Aids and Band-Aids are just different names, but they are actually the same thing.

the truth:

Although there is only one letter difference between Band-Aid and Band-Aid, and their appearances look even more similar, in fact, there are differences between these two types of products in terms of ingredients, efficacy and properties.

In terms of ingredients and efficacy, Band-Aids generally contain drugs, while Band-Aids do not. For example, the Yunnan Baiyao Band-Aids and Benzalkonium Chloride Band-Aids that everyone is familiar with both contain drug ingredients, which can stop bleeding, reduce inflammation and other therapeutic effects. Band-Aids do not contain drugs, and they are more likely to stop bleeding and cover wounds through physical compression.

From the perspective of properties, Band-Aids containing medicines are medicines, and their outer packaging will be marked with "National Medicine Approval Number"; while Band-Aids are medical devices, and a batch number with the word "device" can also be found on the outer shell.

Band-Aids and wound dressings are suitable for trauma with neat, clean, superficial incisions, small wounds, and no need for sutures. They need to be used according to different situations. If you have a small wound, you can use a Band-Aid, and the medicine will make the wound heal faster; if you just want to physically isolate and protect the skin, such as when shoes rub your feet, you can use a Band-Aid. The outer packaging or instructions of the Band-Aid containing medicine will indicate the prohibited groups of people, so everyone must pay attention. In addition, some people are allergic to the drug ingredients in the Band-Aid. If the wound is uncomfortable when using the Band-Aid containing medicine, it is recommended to stop using it immediately.

7. Regular infusion can dredge blood vessels and prevent cardiovascular diseases

gossip:

Infusion is like cleaning the blood vessels, flushing away all the dirt in the blood vessels, so that you will not get cardiovascular disease in the future.

the truth:

The claim that intravenous infusion can unclog blood vessels and prevent cardiovascular disease is not entirely correct.

Some so-called vascular dredge drugs, such as those with antiplatelet aggregation and microcirculation-improving effects, may help improve symptoms in acute events such as cerebral infarction, but they are not recommended for long-term prevention of cardiovascular disease. The prevention of cardiovascular and cerebrovascular diseases relies more on long-term use of antiplatelet and lipid-lowering drugs with clear evidence.

In addition, drugs that improve symptoms are usually used on demand, not regularly. For elderly patients, heart and kidney function may have declined, and frequent infusions may increase the risk of heart failure, edema, etc. Therefore, we should follow the principle of "do not choose infusion if you can take it orally" and avoid long-term regular use of infusion drugs.

8. If you have a fever caused by dengue fever, you can use ibuprofen or aspirin to reduce the fever.

gossip:

Patients who develop a fever after being infected with dengue fever should reduce the fever quickly. Common antipyretic drugs at home, such as ibuprofen and aspirin, can be used.

the truth:

Dengue patients please avoid using ibuprofen and aspirin to reduce fever!

The "Guidelines for the Diagnosis and Treatment of Dengue Fever (2024)" recommends that physical cooling be used as the main method when suffering from dengue fever, such as sponging with warm water, and emphasizes that patients with persistent high fever can use antipyretic drugs such as acetaminophen, and use aspirin, ibuprofen and other non-steroidal anti-inflammatory drugs with caution to avoid aggravating gastritis or bleeding. In addition, patients with underlying heart disease or cerebrovascular disease who have been taking clopidogrel, ticagrelor, warfarin, rivaroxaban, dabigatran etexilate and heparin for a long time should consult a doctor in time and take the medicine under the guidance of a doctor to avoid bleeding. Patients with a history of favism should inform their doctor in time when they see a doctor to avoid inducing hemolysis due to improper use of antipyretic and analgesic drugs.

9. Smart watches stick to high-speed rail glass due to "optical glue phenomenon"

gossip:

When a smart watch is attached to the high-speed rail glass, it is sometimes firmly adsorbed and cannot be removed no matter what. This is caused by the "optical adhesive phenomenon".

the truth:

"Optical bonding" is also known as optical contact bonding - if the conformal accuracy of the objects is less than 1 nanometer, there will be enough surface area in close contact for the molecular interaction to produce an observable macroscopic effect, that is, the two objects stick together. However, the optical bonding phenomenon usually occurs under laboratory conditions and requires extremely high surface flatness and cleanliness. The screen of a smart watch has been finely processed, but its surface smoothness is not yet to the extent that optical bonding occurs. Similarly, although the window glass of a high-speed rail is highly polished, its surface roughness is not enough to cause this phenomenon.

In fact, whether a smartwatch can fit high-speed rail glass is likely related to its screen film, especially the material properties of the hydrogel film. When the hydrogel film of a watch is attached to a smooth surface such as glass, the air in the middle can be discharged during the bonding process, and its flexible material can form a closed small cavity between the smooth surface, thereby forming negative pressure. This phenomenon is similar to the working principle of bathroom suction cups in our daily life - the generation of negative pressure allows objects to be tightly attached to the smooth surface and can withstand heavy hanging objects.

When the watch is firmly adsorbed on the glass, pulling it hard will not only be useless, but may also damage the watch screen. Therefore, the correct way to remove it is to destroy the adsorption force of this negative pressure. First, you can use air to enter the adsorption area to destroy the negative pressure: take a thin plastic card and carefully insert it into the gap between the watch and the glass, allowing air to gradually enter the fitting area. The second is to use a lubricant: apply a small amount of water or hand sanitizer to the gap, and the lubricant will penetrate and destroy the fitting effect. Third, you can try to rotate the watch or use the temperature difference to remove the watch: hold the edge of the watch and rotate it gently to destroy the tight fit of the adsorption. No matter which method you take, avoid excessive force to avoid damaging the watch or the glass surface.

10. When choosing a thermos cup, you can use the "blow and listen" method

gossip:

Blow into the inner liner of the thermos cup and then put it next to your ear. If there is a distinct "buzzing" sound, it means that the cup has good heat preservation. This method is vividly called the "blow and listen" method on the Internet.

the truth:

This method is not reliable. The so-called "blowing to listen to the sound" is actually similar to the principle of "shell resonance". When people put a half-open object such as a cup to their ears, the airflow outside the cup will enter the cup, and then repeatedly return to the inner wall of the cup and the ear canal, forming a "buzzing" sound. We can hear a "buzzing" sound when we blow air into a cup of any material, and we can even hear the sound without blowing air, because the "buzzing" sound is actually the noise generated by the flow of air.

The vacuum layer technology of the thermos is the key to determining the insulation effect. Unlike conventional cups, the thermos is equipped with a vacuum layer and a small mouth, which can block heat conduction and heat convection; the outer wall of the inner liner is often plated with a layer of silver or copper, which helps to reduce heat radiation. For ordinary consumers, it is difficult to judge the quality of the process. Therefore, it is recommended that consumers buy products with compliance marks and certificates when purchasing thermos. In addition, you can also choose a thermos by comparing the insulation test reports of different products.

The monthly "science" rumor list is guided by the Beijing Association for Science and Technology, the Beijing Municipal Cyberspace Administration, and the Capital Internet Association, and jointly released by the Beijing Science and Technology Journalists and Editors Association and the Beijing Regional Website Joint Rumor-Refuting Platform, and is supported by the Science and Technology Journalists and Editors Professional Committee of the China Science Writers Association, the China Evening News Science Editors and Journalists Association, the Shanghai Science Communication Association, and the Institute of Science and Technology Information of the Beijing Academy of Science and Technology.

Sources of this issue: People's Daily Health Client, Science Rumor Refutation, Science and Technology Daily, Science Popularization China, Healthy China, China Consumer News, Tencent Jiuzhen, Digital Beijing Science Center WeChat Official Account, Sanqin Metropolis Daily