Rumor 1: [Eat a pack of instant noodle requires liver detoxification for 32 days] The noodles are all deep-fried, and BHT is added to the oil. The scary thing is that the instant noodles are packed in a bowl. The material of the bowl is polystyrene. BHT, but when encountering high temperature during the brewing process, these substances will dissolve. The dangerous amount of polystyrene ingested by the human body per kilogram of body weight per day is 0.001 mg, and the dissolved amount of a bowl of instant noodles is 0.015 mg! Send it to your friends who love instant noodles.
Rumor 2: Mr. Zhang, a nutritionist from the Knott Nutrition Center of Zhejiang University, said that this statement of netizens is scientific and well-founded. But it is not that instant noodles are toxic, but the ingredients of instant noodles contain many substances that the human body does not need. "The liver is the detoxification organ of the human body. As long as the human body ingests unnecessary substances, it will be integrated and excreted by the liver, usually a cycle of 32 days. People eat instant noodles, fried puffed food and other foods, and those substances that the human body does not need are eliminated. Such a cycle is required for liver integration and excretion.”[1]
How dangerous is BHT in Instant Noodle?
The full name of BHT is 2,6-di-tert-butyl-p-cresol (Butylated Hydroxytoluene), which is an antioxidant. In food, it is widely used as an antioxidant for oils and fats. Edible oils all contain some unsaturated bonds, which will be oxidized in the air, resulting in what is commonly referred to as "halal flavor". In fact, oxidation has already occurred before the appearance of halal flavor, and halal flavor is only produced when certain oxidation products are abundant to a certain extent. There are some oxidation products that are harmful to the human body.
The role of BHT is to protect the oil by stepping forward to be oxidized first when the oil is threatened by oxidation. As a food additive, its safety has been extensively reviewed. The Food and Agriculture Organization of the United Nations and the World Health Organization's Joint Expert Committee on Food Additives (JECFA) set the tolerable daily intake of BHT at 0.3 mg per kilogram of body weight. For adults, that roughly equates to around 20 mg per day.
According to the current Chinese national standard for food additives, the dosage of BHT in different foods (including fried noodles) is generally 0.2 grams per kilogram of fat. According to the calculation of 100 grams of instant noodles per pack, usually with 20% oil content, if you eat 5 packs of instant noodles every day and eat them for many years, the BHT in them will not harm your health. Of course, BHT may also come from other foods, but if a person eats 5 packets of instant noodles a day, he probably won't be able to eat any other foods.
Whether large amounts of BHT affect health is indeed debated. But internationally, China, the United States and the European Union all allow its use. Nor is it the only antioxidant that can be used in oils. There is also a trend in the food industry to use other antioxidants in its place, such as vitamin E.
How Harmful is Polystyrene in Instant Noodle Bowls?
Another argument for the "toxicity" of instant noodles is that the bowl of instant noodles is made of polystyrene, which releases the monomer styrene when heated, and styrene is carcinogenic.
Harvard School of Public Health and other institutions published a comprehensive assessment of the potential health risks of styrene in the "Journal of Toxicology and Environmental Health, Part B" in 2002. The relevant conclusions are briefly described as follows:
Styrene is a widely used industrial raw material. Due to the development of modern industry, it is also present in the air, with typical values on the order of 1ppb (1ppb is equal to one part in a billion). In fact, it also occurs naturally in some foods, such as strawberries, beef, and peppers. A certain amount of styrene is also produced during the production of wine and cheese.
Many studies have been done on the safety of styrene. In terms of carcinogenicity, high doses of styrene have been shown to be carcinogenic in mice. This "large dose" is on the order of tens of milligrams per kilogram of body weight. Other health hazards, such as neurological and respiratory damage, also require large doses.
The place with the highest styrene content in the environment is the reinforced plastics factory. An epidemiological survey found that the incidence of lung cancer and respiratory tract cancer among factory workers was higher. Further analysis of the data, however, found that the increase came from workers at the plant who were least exposed to styrene. This suggests that the culprit behind the rise in cancer rates in the survey was not styrene, but something else.
The current experimental and statistical data do not support the conclusion that styrene is carcinogenic or harmful to health at conventional doses. However, due to the limitations of statistical data and experimental results, this possibility cannot be ruled out.
According to the common sense of "everything is poisonous, as long as the dose is sufficient", the difference between the intake and the safe amount needs to be paid attention to. The safe intake established by JECFA is 0.04 mg per kilogram of body weight per day. The U.S. Food and Drug Administration believes that this harmful dose of styrene is unlikely to be released from polystyrene packaging, so it allows it to be used in food. Europe and Japan also allow its use.
In China, the situation is more complicated. According to "Hygienic Standard for Polystyrene Resin for Food Packaging (GB9692-1988)" and "Hygienic Standard for Polystyrene Molded Products for Food Packaging (GB9689-1988)", polystyrene foamed plastic can be used to make disposable tableware. However, due to reasons such as "polystyrene may release harmful substances at high temperature", "causing white pollution" and "the quality of products of illegal enterprises cannot be guaranteed", "disposable foam plastic tableware including polystyrene tableware" "It has been included in the list of "eliminated products" since 2005. One region has implemented local ordinances banning such tableware. Considering the foreign situation, safety analysis and the benefits of using it, there have been calls to remove it from the list of obsolete products recently.
Styrofoam is only an option for instant noodle bowls. What material the instant noodle bowls on the market are made of currently needs to be judged according to the specific product. However, in any case, the rumor that "the dangerous amount of polystyrene ingested by the human body per kilogram of body weight per day is 0.001 mg, and the amount dissolved in a bowl of instant noodles is 0.015 mg" has no basis.
What are the "unwanted substances" in the seasoning
Zhang, a nutritionist at the Knott Nutrition Center of Zhejiang University, said, "Instant noodles contain a lot of substances that the human body does not need." The teacher Zhang did not explain the "what" substances the human body does not need in the instant noodle seasoning, but such a general statement is actually meaningless.
There is nothing special about the condiments of instant noodles. Like other convenience food accessories, they are mainly "conventional condiments" such as salt and oil, and some "food additives" such as flavors, pigments, antioxidants, and preservatives. Many people regard food additives as "substances that the human body does not need". From a nutritional standpoint, these substances are usually really unnecessary. But they each play a specific role in food. Antioxidants, for example, without which the oils in the dressing can go stale very quickly. The ingredients produced by different instant noodle manufacturers are not exactly the same, but as long as the ingredients meet the national standards, they will not harm health.
Most instant noodle ingredients contain a relatively large amount of salt. From the perspective of controlling salt intake, the seasoning of instant noodles is indeed unhealthy. Some people advocate not to add all the condiments, from the perspective of reducing salt intake is also reasonable.
Does the liver have a 32-day detoxification cycle?
There are various ingredients in food. Not only processed foods, but even "natural foods" contain ingredients that are "unwanted by the human body." There are several possibilities for such substances to enter the human body:
It is not absorbed and is directly excreted through the gastrointestinal tract. Such as insoluble dietary fiber, or solid food that does not dissolve in the gastrointestinal tract.It is absorbed into the blood and metabolized into other substances in the liver, which is commonly referred to as "detoxification".Products that are decomposed in the liver, or substances that are not decomposed, are mainly filtered by the kidneys and excreted in urine (a small amount is excreted in bile).Part of it goes through the blood circulation to certain parts of the body, where it harms the normal functioning of the cells.
The first three situations are not harmful to health. Condition 4 is exacerbated if the intake is too high, exceeding the processing capacity of the liver and kidneys.
For instant noodles, the fourth situation does not occur in qualified products and normal consumption. In the second and third cases, the rate of decomposition and excretion is determined by specific substances, rather than following the so-called "detoxification cycle" of the liver. That is to say, some substances are excreted quickly, and some substances are excreted relatively slowly. The rate at which a substance is excreted is usually measured by the time it takes to excrete 50% or 90% of the time. The time for the concentration to drop by half in a tissue is defined as the "half-life". If this time is short, such as a few hours or a day or two, the substance is considered "not accumulating". This is the case with all kinds of food additives. If this period is long, such as months or even years, the substance is considered to "build up" in the body. This is the case with many heavy metal pollutants.
For example, the half-life of styrene is 8 to 9 hours based on metabolite concentrations in urine, and 2 to 4 days based on adipose tissue concentrations. The metabolic kinetics of BHT are complex, with a half-life between 9 and 11 hours after a single feeding to mice. Other food additives are roughly in a similar time frame. No matter which number you press, there will be no "32-day detoxification cycle."
JECFA takes into account the health effects of the substance at the highest possible levels in the body when formulating safe intake levels. Therefore, as long as the safe intake standard is met, it can be considered that there is no impact on health.
Conclusion
Rumors smashed. Instant noodles itself is not a "healthy food". Its problems are that it is high in calories, has a single nutrient composition, and often has a lot of salt. As a convenience food, it should only be used as an emergency meal, not a regular staple. However, these rumors that "instant noodles are poisonous" are speculations used to create panic, and there is no scientific basis to support them.
