Clipping Board » Dangerous Medicinal Tonics ─ Nutrients should be moderate in the body—excessive supplementation only becomes a burden.
July 21, 2009, Beijing Science and Technology News
This summer, lemon juice beverages have sprung up like mushrooms, such as Nongfu Spring's "Water-soluble C100" and Huiyuan's "Lemon me"... These drinks, marketed as being rich in high levels of vitamin C, have gained popularity among many consumers. As a nutrition expert, Yu Kang, deputy chief physician of the Nutrition Department at Peking Union Medical College Hospital, does not advocate drinking vitamin C beverages. He said that while occasional consumption of a few bottles of vitamin C drinks may not show adverse reactions, prolonged intake will definitely bring some negative effects to the body.
Vitamin C has long been favored. As early as the 18th century, due to a lack of fresh fruits and vegetables, sailors on long voyages were commonly threatened by scurvy. It wasn't until 1911 that humans determined this was caused by a deficiency of vitamin C. Research has confirmed that this water-soluble nutrient helps delay aging by promoting collagen production in the skin, keeping it elastic and radiant.
"If the vitamin C in juice beverages is the natural vitamin C contained in the fruits themselves, then consuming a bit more is not a big issue. As long as it does not exceed the daily maximum intake (1000 mg), it is safe for consumers," said Chen Fang, Secretary-General of the Youth Committee of the Chinese Institute of Food Science and Technology. "However, many juice beverages today undergo high-temperature processing, which can cause natural vitamin C to be lost. Therefore, the vitamin C in these beverages is largely synthetic."
As early as 2006, Fan Zhihong, an associate professor at the College of Food Science and Nutritional Engineering at China Agricultural University, conducted a survey on vitamin C beverages in Beijing.
Fan Zhihong found that all products labeled as containing vitamin C exceeded their stated vitamin C content. For example, a product labeled as containing 25–50 mg of vitamin C per 100 ml actually measured 62 mg. Some products had actual values two to three times higher than their labeled values.
Fan Zhihong also discovered that most beverage products contained over 40 mg/100 ml, with a single bottle providing more than 200 mg of vitamin C—more than twice the recommended daily intake (100 mg). Even some juices and juice beverages that did not specify vitamin C content contained relatively high levels of the nutrient.
Moreover, many products prominently display the name of the fruit while minimizing the word "beverage," deliberately blurring the distinction between fruit juice and juice beverages. However, according to national standards, these "beverage" products must contain no less than 10% pure fruit juice, typically ranging between 10% and 20%. This means most of the content is water and sugar, with fruit flavor primarily coming from added fruit essences, and the nutritional components diluted by 5 to 10 times.
Chen Fang said that if the vitamin C added to juice is natural, even exceeding the recommended daily intake generally does not cause side effects because natural vitamin C is extracted from plant fruits and may contain other substances like natural bioflavonoids. However, if the added vitamin C is synthetic, excessive consumption could pose risks. Synthetic vitamin C, produced in laboratories, is often used in pharmaceutical preparations, such as vitamin C tablets, which tend to have high doses. Long-term intake may lead to excessive oxalate production in the body, increasing the risk of conditions like uric acid stones.Fan Zhihong believes that the main reason companies add so much vitamin C to beverages largely comes down to its three major advantages: low cost, rapid solubility, and a refreshing flavor. The price of vitamin C is surprisingly cheap—even after recent price hikes, a kilogram of pure vitamin C costs only 90 yuan. Adding 250 milligrams of vitamin C to a bottle of beverage amounts to just about 2 cents.
"Vitamin C isn't just a vitamin; it also acts as an acidulant, providing a fresh and tangy sourness. Adding it to beverages makes them more appealing. So, rather than being for health, it’s more about taste. And to some extent, consumers buy these products because they’re drawn to the refreshing flavor," Fan Zhihong said.
A reporter observed in supermarkets that Nongfu Spring’s "Water Soluble C100" prominently displays on its packaging: "The vitamin C content per bottle is equivalent to five and a half fresh lemons." Meanwhile, Huiyuan’s "Lemon Me" claims to "add honey to balance the acidity of lemons, making the taste even fresher." Compared to traditional carbonated drinks or mineral water, lemon juice beverages aren’t cheap. Nongfu Spring’s "Water Soluble C100" sells for 4.5 yuan per bottle, while Huiyuan’s "Lemon Me" is priced at 3.9 yuan per bottle.
Chen Fang noted that from a vitamin C supplementation perspective, if one regularly consumes fruits and vegetables, there’s no need to rely on juice drinks for vitamin C. However, for those who seldom eat fruits or vegetables, drinking vitamin C-fortified beverages is acceptable, but it’s best not to exceed one bottle per day.
"More vitamin C isn’t always better. Vitamin C drinks aren’t suitable for everyone," Yu Kang said. While the vitamin C content in these beverages isn’t at medicinal levels, they are unsuitable for individuals with chronic diarrhea, ulcers, kidney stones, blood disorders, or gout. For example, patients with kidney stones may experience worsened conditions due to increased oxalate levels from additional vitamin C intake.
Additionally, the molecular structure of vitamin C is highly prone to oxidation. In alkaline conditions, under light, or in the presence of oxidizing agents, vitamin C is very unstable. Therefore, if a vitamin C drink is opened but not consumed immediately, the vitamin C may degrade, especially in high temperatures.
"If you can get vitamin C from fruits and vegetables, why bother with vitamin C drinks?" Yu Kang argues that the best way to supplement vitamin C is through natural foods. Regardless of age or gender, whole foods should always be the top choice. "Besides vitamin C, fruits contain many other nutrients, such as dietary fiber, antioxidants, calcium, and phosphorus—none of which are present in vitamin C drinks."
(Editor: Zhaxi)
Source: http://env. people. com. cn/ BIG5/ 9689833. html
Vitamin C Drinks Harm Health? Long-term Use May Cause Kidney Stones?
This summer, lemon juice beverages have sprung up like mushrooms, such as Nongfu Spring's "Water-soluble C100" and Huiyuan's "Lemon me"... These drinks, marketed as being rich in high levels of vitamin C, have gained popularity among many consumers. As a nutrition expert, Yu Kang, deputy chief physician of the Nutrition Department at Peking Union Medical College Hospital, does not advocate drinking vitamin C beverages. He said that while occasional consumption of a few bottles of vitamin C drinks may not show adverse reactions, prolonged intake will definitely bring some negative effects to the body.
Vitamin C has long been favored. As early as the 18th century, due to a lack of fresh fruits and vegetables, sailors on long voyages were commonly threatened by scurvy. It wasn't until 1911 that humans determined this was caused by a deficiency of vitamin C. Research has confirmed that this water-soluble nutrient helps delay aging by promoting collagen production in the skin, keeping it elastic and radiant.
"If the vitamin C in juice beverages is the natural vitamin C contained in the fruits themselves, then consuming a bit more is not a big issue. As long as it does not exceed the daily maximum intake (1000 mg), it is safe for consumers," said Chen Fang, Secretary-General of the Youth Committee of the Chinese Institute of Food Science and Technology. "However, many juice beverages today undergo high-temperature processing, which can cause natural vitamin C to be lost. Therefore, the vitamin C in these beverages is largely synthetic."
As early as 2006, Fan Zhihong, an associate professor at the College of Food Science and Nutritional Engineering at China Agricultural University, conducted a survey on vitamin C beverages in Beijing.
Fan Zhihong found that all products labeled as containing vitamin C exceeded their stated vitamin C content. For example, a product labeled as containing 25–50 mg of vitamin C per 100 ml actually measured 62 mg. Some products had actual values two to three times higher than their labeled values.
Fan Zhihong also discovered that most beverage products contained over 40 mg/100 ml, with a single bottle providing more than 200 mg of vitamin C—more than twice the recommended daily intake (100 mg). Even some juices and juice beverages that did not specify vitamin C content contained relatively high levels of the nutrient.
Moreover, many products prominently display the name of the fruit while minimizing the word "beverage," deliberately blurring the distinction between fruit juice and juice beverages. However, according to national standards, these "beverage" products must contain no less than 10% pure fruit juice, typically ranging between 10% and 20%. This means most of the content is water and sugar, with fruit flavor primarily coming from added fruit essences, and the nutritional components diluted by 5 to 10 times.
Chen Fang said that if the vitamin C added to juice is natural, even exceeding the recommended daily intake generally does not cause side effects because natural vitamin C is extracted from plant fruits and may contain other substances like natural bioflavonoids. However, if the added vitamin C is synthetic, excessive consumption could pose risks. Synthetic vitamin C, produced in laboratories, is often used in pharmaceutical preparations, such as vitamin C tablets, which tend to have high doses. Long-term intake may lead to excessive oxalate production in the body, increasing the risk of conditions like uric acid stones.Fan Zhihong believes that the main reason companies add so much vitamin C to beverages largely comes down to its three major advantages: low cost, rapid solubility, and a refreshing flavor. The price of vitamin C is surprisingly cheap—even after recent price hikes, a kilogram of pure vitamin C costs only 90 yuan. Adding 250 milligrams of vitamin C to a bottle of beverage amounts to just about 2 cents.
"Vitamin C isn't just a vitamin; it also acts as an acidulant, providing a fresh and tangy sourness. Adding it to beverages makes them more appealing. So, rather than being for health, it’s more about taste. And to some extent, consumers buy these products because they’re drawn to the refreshing flavor," Fan Zhihong said.
A reporter observed in supermarkets that Nongfu Spring’s "Water Soluble C100" prominently displays on its packaging: "The vitamin C content per bottle is equivalent to five and a half fresh lemons." Meanwhile, Huiyuan’s "Lemon Me" claims to "add honey to balance the acidity of lemons, making the taste even fresher." Compared to traditional carbonated drinks or mineral water, lemon juice beverages aren’t cheap. Nongfu Spring’s "Water Soluble C100" sells for 4.5 yuan per bottle, while Huiyuan’s "Lemon Me" is priced at 3.9 yuan per bottle.
Chen Fang noted that from a vitamin C supplementation perspective, if one regularly consumes fruits and vegetables, there’s no need to rely on juice drinks for vitamin C. However, for those who seldom eat fruits or vegetables, drinking vitamin C-fortified beverages is acceptable, but it’s best not to exceed one bottle per day.
"More vitamin C isn’t always better. Vitamin C drinks aren’t suitable for everyone," Yu Kang said. While the vitamin C content in these beverages isn’t at medicinal levels, they are unsuitable for individuals with chronic diarrhea, ulcers, kidney stones, blood disorders, or gout. For example, patients with kidney stones may experience worsened conditions due to increased oxalate levels from additional vitamin C intake.
Additionally, the molecular structure of vitamin C is highly prone to oxidation. In alkaline conditions, under light, or in the presence of oxidizing agents, vitamin C is very unstable. Therefore, if a vitamin C drink is opened but not consumed immediately, the vitamin C may degrade, especially in high temperatures.
"If you can get vitamin C from fruits and vegetables, why bother with vitamin C drinks?" Yu Kang argues that the best way to supplement vitamin C is through natural foods. Regardless of age or gender, whole foods should always be the top choice. "Besides vitamin C, fruits contain many other nutrients, such as dietary fiber, antioxidants, calcium, and phosphorus—none of which are present in vitamin C drinks."
(Editor: Zhaxi)
Source: http://env. people. com. cn/ BIG5/ 9689833. html