Do the pigments in ultra-processed foods really cause cancer?

Key Points

★ Most snacks, drinks, desserts, and industrial bagged bread are ultra-processed foods and should not be eaten in large quantities.

★ Ultra-processed foods use a variety of additives, often synthetic colors, which pose a certain risk of cancer.

★ Although ultra-processed foods are convenient and delicious, they are actually not healthy.

Christmas has just passed, I wonder if you have eaten the Christmas-exclusive gingerbread?

Christmas gingerbread in various shapes is very cute. | Tuchong Creative

In addition to gingerbread, there are also convenient foods such as chocolate and ice cream, which are not only beautiful and atmospheric, but also delicious. They actually have a scary name - ultra-processed food.

In recent years, the discussion about ultra-processed food has attracted much attention, and more and more voices tend to say that eating ultra-processed food is harmful to health! The latest research also mentioned that the pigments used in ultra-processed food have a carcinogenic risk!

So, what exactly are ultra-processed foods? Do the pigments in them really cause cancer? Let's talk about ultra-processed foods.

01

Ultra-processed foods

What is it?

According to the international food classification standard "NOVA", food can be divided into four categories according to the degree of processing:

Simply put, ultra-processed food is food that has gone through multiple processing steps and usually contains a variety of food additives, and there are almost no complete ingredients in it. For example, sweet drinks, candies, ice cream, instant noodles, industrial bagged bread, donuts, potato chips, etc.

Look at the representative ultra-processed foods in the above chart. Their common characteristics are high oil, high fat, high sugar and high calories. After going through complicated processing procedures, they not only produce some harmful substances, such as trans fatty acids, acrylamide, etc., but also lose a lot of nutrients.

Most cookies and candies are ultra-processed foods. | Tuchong Creative

To date, many studies have revealed the harm that ultra-processed foods can cause to human health, such as accelerating aging and increasing the risk of obesity, high blood lipids, high blood pressure, cancer, heart disease, depression and other diseases. [1]

Recently, new attention has been paid to the dyes in ultra-processed foods, which we usually call pigments. You know, the colorful foods we eat are inseparable from pigments. But new research has found that the dyes in ultra-processed foods seem to induce cancer!

02

Pigments from ultra-processed foods

Does it really cause cancer?

Adding coloring makes food more colorful, more attractive, and more appetizing. But have you ever thought carefully about whether these colorings are really healthy to eat?

If we want to understand the impact of pigments on the body, we must first know what pigments we usually eat.

There are two types of pigments, including natural pigments and artificially synthesized pigments. Compared with the two, synthetic pigments are cheaper to use, more stable in coloring, and more colorful, so most food manufacturers choose to use synthetic pigments.

Various food colorings. | Tuchong Creative

However, research on the harmful effects of synthetic pigments on health has been exposed one after another. From the development of the first pigments made from coal tar to the present, pigments that are obviously harmful to the human body are gradually being eliminated, especially some azo compound synthetic pigments that are obviously harmful to the human body. For example, butter yellow, which was used to color margarine, can cause liver cancer in humans and animals; orange yellow may cause liver cancer, intestinal cancer and malignant lymphoma. [2]

The new study suggests that bacteria in the intestines can break down synthetic pigments into molecules known to cause cancer. Synthetic pigments can also bind to DNA and proteins in cells, stimulate the body's inflammatory mechanisms, and increase the risk of colorectal cancer. Synthetic pigments such as Allura Red, Lemon Yellow, and Sunset Yellow can cause DNA damage in colon cancer cells in experiments. In other words, synthetic pigments may stimulate and affect the proliferation of cancer cells.

Cancer cells divide uncontrollably, and DNA damage can make this worse. The grey circles in the image represent cancer cells. | thebraintumourcharity.org

In addition to synthetic pigments, other additives in ultra-processed foods may also affect health. A related study in the Chinese Journal of Food Hygiene mentioned that 77.9% of foods in my country use multiple additives. Most ultra-processed foods contain more than two types of food additives, with a maximum of 29. The combined use of food additives may produce a combined effect and form a cumulative risk, posing certain health risks to the human body. [3]

Some researchers also believe that sodium nitrite, tartrazine and sunset yellow have certain synergistic effects, which will increase health risks. Their combined use should be avoided and the dosage should be kept at a low level. [4] The combined use of food additives poses a higher health risk than using them alone. In addition, the use of pigments beyond the scope and in excessive amounts is still common, for example:

In 2005, the non-food dye "Sudan Red 1" was detected in a batch of chili sauce in Beijing.

The notorious "Sudan Red No. 1" is banned in most countries around the world. | Source: Internet

In 2006, Wuhan Industry and Commerce Department detected the banned industrial dye "Basic Orange II" during an inspection of the Wuhan dried tofu products market.

In 2015, sunset yellow, lemon yellow and carmine were detected in Shanxi pastries, cooked meat products and other products.

In 2021, an Internet celebrity beverage shop violated the regulations by adding "sunset yellow" to tea drinks.

…

In June this year, it was discovered that some tea drinks were excessively added with sunset yellow. | Source: Internet

03

Contains synthetic pigments

Can I still eat it?

With so many risks associated with synthetic colors in ultra-processed foods, how can we ensure our diet is safe?

In fact, in order to ensure food safety, my country has clear regulations on the use of pigments. At present, my country allows the use of six synthetic pigments: carmine, amaranth, lemon yellow, sunset yellow, brilliant blue, and indigo. The "Standards for the Use of Food Additives" also clearly stipulates the scope and dosage of use.

In my country, the amount of synthetic pigments used in soft drinks such as juice is very small. | Tuchong Creative

These synthetic pigments can only be used in small amounts in soft drinks, cold drinks, candies, mixed alcoholic beverages and fruit juices, and generally should not exceed 1:10,000. Synthetic pigments are not allowed in other processed foods, especially infant foods. [2]

For various food additives, they must undergo strict safety risk assessments to prove that they are harmless to the human body before they can be used within a conservative range that is smaller than the safe dose. These regulations are reliable for a single type of food additive.

So, how can we reduce the harm to health caused by ultra-processed foods?

Snacks are delicious, but they are not as good as meals. | Tuchong Creative

① Don’t eat snacks before meals: Eating snacks before meals will increase satiety, affect your ability to eat meals, and may lead to malnutrition. If you really need to eat, plan to eat 1 to 2 hours before meals.

② Choose a shorter ingredient list: If you really have to eat a certain type of ultra-processed food, compare the ingredient lists of the same brand and choose the one with the least additives in the ingredient list, and avoid choosing foods with a long ingredient list.

③ Don’t be too “lustful”: Try not to choose foods that look particularly bright or colorful.

④ Pay attention to the nutritional information: When purchasing, compare the nutritional information of the same product and choose the one with the lowest calorie, fat and sodium content.

⑤ Adequate intake of fruits and vegetables: Eat enough vegetables and fruits every day, 300-500 grams of vegetables per day. One fist of cooked vegetables is about 100 grams. It is recommended to eat 1-2 fists at each meal; 200-350 grams of fruit per day, such as 2-3 kiwis.

Although we cannot completely distance ourselves from ultra-processed foods, we can try to reduce their consumption. At the same time, food safety supervision will be stricter to prevent unqualified products from entering our lives to the greatest extent possible.

Author | Xue Qingxin, member of Chinese Nutrition Society, registered nutrition technician, health manager, public nutritionist

Review | Song Shuang, Associate Researcher, Institute of Nutrition and Health, Chinese Center for Disease Control and Prevention

Editor | Jiang Fan

Editors: Jiang Fan, Ding Zong

References:

[1] Eating over-processed foods increases the risk of cancer and other diseases[J]. Food Industry, 2019, 40(07): 222.

[2] Zhu Haiying, Huang Wanqi. Problems and countermeasures of synthetic pigments under the background of food safety law [J]. Modern Medicine and Health, 2011, 27(08): 1259-1262.

[3] Chang Jiongjiong, Li Shanyawen, Yong Ling, Xiao Xiao, Yang Dajin, Song Shufeng, Yang Jianjun, Xu Haibin, Song Yan. Combined use of food additives and cumulative risk assessment in my country[J]. Chinese Journal of Food Hygiene, 2021, 33(02): 206-214. DOI: 10.13590/j.cjfh.2021.02.016.

[4] He Lin. Study on the genotoxicity and combined toxicity of several food additives [D]. Guangzhou: Jinan University, 2008.

[5]Urgent action needed to reduce harms of ultra-processed foods to British children. Retrieved JUNE 14, 2021, from https://medicalxpress.com/news/2021-06-urgent-action-ultra-processed-foods-british.html

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