The latest research found that "Sugar oranges can no longer be eaten"? The truth...

Rumor: "'The latest research shows that sugar oranges are no longer edible'"

Today, a piece of news about "Sandang tangerines really can no longer be eaten" went viral on Weibo. The news said that a study in Nature showed that fructose promotes tumor growth, and sandang tangerines contain a lot of fructose; and that the sandang tangerines grown now are sweetened with deacidifiers, which contain toxic heavy metals. After this news was released, it spread widely and caused many people to panic about sandang tangerines.

Rumor analysis: This statement is totally untenable.

First of all, the paper mentioned in the message does exist, but it completely distorts the original meaning of the paper.

Secondly, the country currently has strict supervision over food safety, and the correct use of nutritional supplements to sweeten foods has no side effects, so there is no need to worry about the formal practices in agricultural planting.

The end of the year is approaching, and it is time to eat tangerines again.

The sugar orange gets its name because it is as sweet as sugar. It is fresh, has no residue and has a delicate taste. Because it is so delicious, many people can't stop eating it once they start.

However, today a message on Weibo that "Sugar oranges really can't be eaten anymore" attracted widespread attention from netizens.

The news said that a study published in the top journal Nature found that dietary fructose would be metabolized in the liver and converted into nutrients needed by tumors, which would promote tumor growth and that the fructose in fruits nourishes cancer cells.

He also said that the sugar oranges currently grown are sprayed with a pesticide called deacidifier, which can inhibit the synthesis of citric acid and also has the effect of ripening. The deacidifier contains a large amount of heavy metals, including lead, arsenic and other toxic heavy metals.

Screenshot of the network platform

What's the story behind this study? Is it true that we can no longer eat sugar oranges?

What happened to the thesis?

The paper mentioned in the news does exist, but it completely distorts the original meaning of the paper and exaggerates the harm of sugar oranges.

First of all, this study [1] is an animal experiment. This study was conducted on mice that had already developed cancer. The mice were fed high fructose syrup, and the results showed that the tumors of these mice grew faster. The paper concluded that tumor cells cannot directly utilize fructose because tumor cells do not express KHK-C (a key enzyme in fructose metabolism), but some intermediate products produced by liver metabolism (such as blood phosphatidylcholine LPC) can be absorbed and utilized by tumor cells, thereby promoting tumor growth. Therefore, fructose may promote tumor cell growth.

Most importantly, this study did not mention tangerines or other fruits at all. The tangerines were completely distorted by the author. It was interpreted like this: "Because high fructose syrup contains a lot of fructose, tangerines also contain fructose, so tangerines are carcinogenic and should not be eaten."

However, if we follow this deduction, then almost all sweet fruits cannot be eaten because they "contain fructose", because fructose is a very common type of sugar in many fruits, so no fruit can be eaten.

In fact, this study is a basic medical study, and the level of evidence is relatively weak. There are many similar basic medical studies, including animal experiments and in vitro cell experiments. If you often read scientific news, you will see that many similar studies are published every year, but they are still a long way from clinical application.

For us, we can just arrange three meals a day according to the dietary guidelines and there is no need to worry too much.

What is a deacidifier?

Regarding “deacidifiers”, some local agricultural departments have found that “cyclamate”, “deacidifiers”, “deacidifiers” and “deacidifying sweeteners” are all unregistered “three-no” products[2], and some of these products may contain arsenate.

Arsenate residues can easily pose a threat to the environment and human health. In the current food safety management, their use is prohibited. Both users and providers will be subject to legal sanctions, especially as the country currently has strict supervision over food safety. Once investigated, fruit farmers and fruit dealers will have to bear corresponding legal responsibilities. Many fruit farmers are also aware of the harm of this thing and generally do not agree to use it.

However, there are no side effects if nutritional supplements are used correctly to sweeten foods, and there is no need to worry about formal practices in agricultural planting.

At present, many fertilizer manufacturers are promoting fertilizers containing phosphorus, potassium and other elements to increase the sweetness of citrus fruits. Such nutrient solutions are formally registered and can be used normally. They are harmless to the trees and will not cause any excessive pesticide residues. Farmers can choose foliar fertilizers, potassium dihydrogen phosphate and the like to increase the sweetness of the fruit. These are all nutrient fertilizers with no toxic side effects. The mechanism of action of using high-phosphorus and high-potassium foliar fertilizers is to improve photosynthesis efficiency, increase photosynthetic products, accelerate the production and conversion of nutrients, and accumulate organic matter.

In general, the regular tangerines we buy are safe to eat.

Looking in the mirror of rumors

This so-called "new research" rumor is a typical rumor that is a one-sided and exaggerated interpretation of scientific research papers. This type of rumor is usually disguised as "the latest research" and gives some seemingly authoritative, professional and exaggerated conclusions.

These new studies usually have small sample data and are mostly limited to animal experiments. Many studies have not reached a conclusion, but some interpreters often ignore these key factors, exaggerate those inconclusive conclusions, and even make associations out of thin air, infer some so-called results, and widely disseminate them, leading to the spread of rumors and causing public panic.

For many netizens, most people do not read the original documents, and many contents are too professional to be understood. Many people are easily misled when they see widely circulated news.

Leave professional matters to professionals. It is recommended that you consult the professional judgment of authoritative people.

Author: Ruan Guangfeng, Director of the Science and Technology Department of the Kexin Food and Health Information Exchange Center

Review｜Han Hongwei, Researcher at the National Food Safety Risk Assessment Center

Zhang Yu, researcher at Chinese Center for Disease Control and Prevention, national health science expert