This "Internet celebrity" food contains excessive amounts of heavy metal cadmium! What are the dangers of eating it as a meal every day?

Image from: Weibo

In recent years, a "notorious" internet celebrity has emerged - snail noodles.

This "dark king" in the food industry, the stinky-smelling snail noodle has become so popular for some reason and has become a national internet celebrity. I have bought snail noodles several times this year.

Data from the Liuzhou Municipal Bureau of Commerce shows that the output value of bagged snail noodles has reached 4.98 billion yuan in the first half of this year, and is expected to reach 9 billion yuan for the whole year.

However, in the past two days, snail noodles have become a hot topic.

A test conducted on 15 types of snail noodles, including Haohuanluo, Liziqi, and Three Squirrels, found that the cadmium content in Liujiangrenjia's snail noodles was 0.221 mg per kilogram, and it was said that its cadmium content was "definitely above the standard."

Does the cadmium content in this snail noodle really exceed the standard? Can we still eat it safely? What will happen if we eat snail noodles every day?

I'm Busy, Quick Reading Edition

● The cadmium in snail noodles mainly comes from environmental pollution, including soil and water.

● Cadmium’s main health hazard is that it causes “Itai-itai disease”.

● The test results showing that the cadmium content in snail noodles exceeded the standard are a misinterpretation of the standard.

● The main problem with eating snail noodles as a meal every day is that the nutrition is single and the energy is high.

● Paying attention to a diverse and balanced diet can reduce the health risks of cadmium.

1

Why is there cadmium in snail noodles?

Actually it comes from environmental pollution.

Cadmium is a heavy metal element that is widely used in metallurgy, plastics, electronics and other industries. The zinc-cadmium rechargeable batteries we usually use contain cadmium.

However, cadmium in industrial production is usually discharged into the environment through wastewater, exhaust gas, etc., polluting our air, water and soil, and then enters food through irrigation, planting, etc. Rice is a typical "victim crop".

Therefore, all rice-related foods inevitably contain cadmium, and snail noodles are no exception.

2

What are the hazards of cadmium?

Cadmium is a toxic heavy metal that can accumulate in the human body and the environment for a long time. The main exposure route is entering the human body through food.

Cadmium has different effects on health depending on the way it is taken in. Intake through food such as rice is considered "long-term low doses".

If ingested in small amounts over a long period of time, it will manifest as chronic cadmium poisoning, with the main harm to the kidneys and bones. The kidneys are the most important accumulation site and target organ of cadmium. Cadmium will accumulate in the kidneys, with early toxicity mainly in the proximal tubules of the kidneys, and severe cases can lead to renal failure; the impact on bones is osteomalacia and osteoporosis.

A typical case of chronic cadmium poisoning is the Japanese "Itai-itai disease" that shocked the world decades ago. It manifests itself as pain in the joints and bones of the waist, hands, feet, etc.

In the 1940s and 1960s, the Itai-itai disease broke out in the Jinzu River basin in Toyama Prefecture, Japan. Investigations showed that the number of patients with bone Itai-itai disease on both sides of the Jinzu River was related to the wastewater from the Kamioka zinc smelter of Mitsui Mining and Smelting Company that polluted the arable land. By 1972, there were 258 cases of Itai-itai disease in Japan, of which 128 died, mainly elderly women.

So far, no such clinical poisoning patients caused by food cadmium contamination have been found in China.

Long-term exposure to higher doses of cadmium may also cause digestive tract disorders. In animal experiments, higher doses of cadmium have also shown effects on the reproductive and developmental systems, and in cell experiments, there are some cases of teratogenicity and carcinogenesis. However, there is no reliable research evidence on whether humans have the same effects.

The bigger problem with cadmium poisoning is its long-term nature. Even if cadmium exposure stops, kidney failure symptoms will continue.

3

Does the cadmium content in snail noodles really exceed the standard?

The video stated that the cadmium content in the snail noodles tested was 0.221 mg per kilogram, which is above the standard.

But this is actually a misunderstanding of the standard.

my country's current standards only set limits on cadmium in primary products such as grains, grain milling products, and brown rice. There are no limits on other products made from rice (except baby food), such as rice noodles and snail noodles. (Besides, it still refers to the limits on rice and brown rice.)

Therefore, it is wrong to say that the cadmium content in snail noodles exceeds the standard.

In addition, even if the limit is 0.2, from a technical point of view, there is currently insufficient basis to determine that it exceeds the limit.

The national standard requirement is 0.2, and the inspection method requires retaining two significant digits. The value of 0.221 should be the original value. According to the requirements of "GB/T8170-2008 Rules for Rounding Off Numerical Values ​​and Representation and Determination of Limit Values", this test value cannot be judged as exceeding the standard.

Image from: Weibo user @浣熊JO

4

What are the dangers of eating snail noodles as a meal?

The biggest harm is that the nutrition is too single and it only provides energy.

Nowadays, many types of snail noodles are actually similar to instant noodles, with high oil and salt content, strong taste, high energy, and a satisfying taste.

A netizen said: I gained a lot of weight after eating it for a month... like a balloon.

If you really eat snail noodles as your main meal every day, this is the issue that everyone should be more worried about.

5

Is Cadmium a Worry?

Currently, the cadmium we ingest in our daily diet is within a safe range and does not pose a hazard to our health.

According to my country's dietary survey data, the average cadmium intake of Chinese residents is currently 15.3 μg/kg BW/month, which does not exceed the safety line. Therefore, it can be considered that our risk is very low and there is no need to worry too much.

Besides, everyone only eats snail noodles occasionally, so there is basically no need to worry, so just eat it with confidence.

Image from: freepik.com

6

How can the risks of cadmium be reduced?

Many people are concerned about cadmium in rice.

Cadmium is a harmful pollutant that is really a headache and difficult to completely solve. It has no benefits to the human body, and we should try to keep a distance from it and reduce its intake.

What should we do in daily life? It is recommended to start from the following aspects:

(1) Be careful when buying rice.

Rice is our staple food and the main source of our cadmium intake. At present, my country has very strict requirements on the limit of cadmium in rice. As long as it is a qualified product, there is no problem and it generally does not cause any harm to the human body.

Judging from the information that is often exposed now, the rice in my country with high heavy metal risks is mainly from some southern regions, so you should pay more attention when buying rice, and be sure to buy rice in turns.

(2) Do not eat only rice as your staple food; enrich your staple food categories.

Rice is the daily staple food in my country. For most consumers in my country, it is difficult not to eat rice. However, we can do it and not only eat rice as a staple food.

It is recommended to increase the diversity of diet as much as possible and reduce the dependence on rice (especially rice from a single source). Staple food should also include various whole grains, etc., and should not be completely rice. It can also include oats, buckwheat, corn, potatoes and other whole grains.

Image from: freepik.com

(3) Eat a variety of foods.

Among the patients with Itai-itai disease in Japan, almost all of them come from poor families with a relatively simple food structure. This is because people from poor families have a particularly simple diet and very unbalanced nutritional intake.

In your daily diet, don't just eat one or a few kinds of food. Instead, you should refer to the recommendations of the dietary guidelines to ensure food diversity and eat all kinds of food.

On the one hand, a diversified diet and nutrition can reduce the risk of cadmium intake.

A study established an in vitro gastrointestinal simulated digestion method to analyze the effects of 39 dietary ingredients on the bioavailability of Cd in rice. The results showed that a mixture of multiple components can significantly reduce the solubility of Cd in the intestine, with a reduction rate of 10% to 98%. The study pointed out that tannic acid, titanium dioxide, zinc gluconate, calcium chloride and proanthocyanidins are most effective in reducing the bioavailability of cadmium in rice, with reduction rates of 93% to 97%, 54% to 61%, 32% to 49%, 24% to 32% and 11% to 14%, respectively. After adding dietary ingredients, the relative bioavailability of cadmium in the kidney and liver of mice was reduced by 20% to 58% and 10% to 31%, respectively.

On the other hand, diversified nutrition can also increase our body's resistance to cadmium.

According to Japanese research, people who are deficient in calcium and vitamin D are more sensitive to excessive cadmium. Therefore, ensuring that there is sufficient calcium and vitamin D in your diet may help increase your resistance to cadmium.

References

[1] GB 2762-2017 National Food Safety Standard Limits of Contaminants in Food

[2] GB 5009.15-2014 National Food Safety Standard Determination of Cadmium in Food

[3] GB/T 8170-2008 Rules for rounding off values ​​and expression and determination of limit values

[4] Chen Yao, Wu Weiguo, Liao Luyan. Research progress on the distribution and reduction technology of cadmium in rice[J]. Grain and Oils, 2018, 31(12): 13-15.

[5] Chen Qunfang, Ye Yaoyao, Xu Qing, et al. Research progress on the absorption law of cadmium by rice and safety control technology of rice[J]. Agricultural Science and Technology (English Edition), 2014(10):1801-1804.

[6] Ao Ming, Chai Guanqun, Liu Guihua, et al. Research progress on the absorption and transport of cadmium by rice[J]. Southern Agriculture, 2018, 12(24): 127-128, 131.

[7] Qin Yan, Wei Yanyan, Gu Minghua. Heavy metal content and health risk assessment of rice sold in China[J]. Food Industry, 2020, 41(11): 332-335.

[8]Shuo Sun, Xiaofang Zhou, Yingwen Li, Yongxing Li, Hanping Xia, Zhian Li, and Ping Zhuang

Journal of Agricultural and Food Chemistry 2020 68 (14), 4166-4175

Source: Nutritionist Ruan Guangfeng