A subversive sense of the latest research shows that long-term use of vitamin significant increase in mortality.
■ an authoritative international medical journal published in large-scale studies have shown that vitamin E increased mortality 4%, taking β-carotene increased mortality 7%, vitamin A mortality rate increased by 16%, there is no evidence that vitamin C can promote longevity ... ...
■ "has more than one billion U.S. dollars of vitamin industry is built on this concept: the vitamin may prevent diseases. But people are actually put themselves into an additional risk,"
■ United States Association for Cancer Research has always been the suggestion is that through a balanced dietary intake should be an appropriate amount of vitamins and minerals, rather than relying on medication
The conclusions of a subversive
"Oh my God, Chi Cuoyao up?" Vitamin for several years, the dragon lady was shocked by a recent study concluded.
The authoritative international medical journal published in large-scale studies have shown that vitamin E increased mortality 4%, taking β-carotene increased mortality 7%, vitamin A mortality rate increased by 16%, there is no evidence that vitamin C can live longer ... ...
In North America and Europe, there are about 080 million to 160 million people regularly take vitamins and other health care products rich in antioxidants. In China, Miss Long accustomed to such long-term use is also a number of people not in small groups. May be a fashion, perhaps more and more Chinese people aware of the importance of a healthy, this group the number is steadily increasing.
In the cities, especially the white-collar class, a lot of people who eat junk food all year round would think that taking multi-vitamin tablets easier way than eating fruits and vegetables. Office of the popular women's play, "vitamin woman", the lunch will shrink too, such as Archer-like appetite is small, the afternoon to eat a high-level complex of vitamins, is said to be able to stay in shape. More importantly, they subconsciously believe that both life-sustaining vitamins and metabolic function, but also retard aging, lower cholesterol, help to lose weight, emission of toxins, prevention of chronic diseases, and even prevent cancer. Thus, vitamin supplements nutritional supplements has become the mainstream, a large number of vitamin ads filled with media.
Vitamins, by definition is to maintain the normal function of living organisms essential element is that people are not even for a moment to leave the material. Some vitamins are a type of antioxidant. However I have just released the results of a large study, but ignored the role of taking vitamins to make an almost subversive conclusions. For a time, the people's common sense at odds with the news of the world's major media attention as one of the hot.
February 28, 2007 issue of the international authority of the medical journal "Journal of the American Medical Association" (JAMA) published a joint study by the multi-country study completed. Copenhagen University Hospital, a team --- Kirkland Gandan Bing Group is the main unit of the study. Kirkland Gandan Bing Group is an international authority of the medical evidence-based Organization --- Kirkland partner agencies of the professional team consists of one, it itself has considerable authority. Research on the global anti-oxidants on the results of 68 studies and comprehensive analysis of the sort. Bjelakovic (Goran Bjelakovic, the paper's first author) and others the 1990 Zhi October 2005 published on 68 international studies are divided into two categories, one category is low-bias (low-bias), a class is a high-biased (high-bias). If you do not distinguish between two types of research, analysis showed that the intake of antioxidants, mainly vitamins A, E, C and β-carotene and selenium, human neither good nor bad.
However, what is surprising is that, disregarding the high-bias studies, only a more reliable analysis of 47 studies, the authors believe that "to β-carotene, vitamin A and vitamin E for treatment may increase mortality, while vitamin C and the potential role of selenium on mortality need further study. "
Overall, the mortality rate among those taking anti-oxidants an increase of 5%;, respectively, the mortality rate among those taking vitamin E to increase 4% mortality rate among those taking β-carotene increased by 7% mortality rate among those taking vitamin A increase of 16%.
This is 47 the number of higher-quality research, which involved over 180,938 people. These people were randomly assigned to take anti-oxidants group and the placebo group. Taking anti-oxidants in the group taking considerably more than some of the daily recommended amount of antioxidant doses, while others take the normal dose.
The writer says, "to give a separate β-carotene, vitamin A and vitamin E or other anti-oxidants taken together, have significantly increased mortality rates. There is no evidence that vitamin C can promote longevity ... ... selenium may reduce mortality, but this problem We need more research. "Selenium may be concluded that the only positive recognition of the study where anti-oxidants, the author of selenium given to reduce mortality of about 9%.
Some have questioned some dubious
Bjelakovic and others, research has been called a comprehensive analysis (Meta-analysis), the results of previous studies is a systematic quantitative analysis, the conclusions have considerable reliability. Prior to this, in 2005, another on a comprehensive analysis of vitamin E, also came to similar conclusions, it is a daily intake of 400 international units of vitamin E can increase the 10% mortality (all causes of death).
However, as studies have been criticized in 2005 as Bjelakovic As soon as he and others published research has also been questioned. Some researchers first questioned, Bjelakovic and others in the analysis of many different research results, the criteria used are the same.
Harvard School of Public Health professor of nutrition and epidemiology 斯坦普菲尔 (Meir Stampfer) said, "Bjelakovic analysis of those studies and others there are too many differences, because they are in different groups of people in the investigation of anti - different combinations of oxidant and dose. The scope of both of the 109 home health care for the elderly 3-month study, also includes 22071 male doctors 12 years of investigation. Therefore, such a study is not conducive to people's understanding, on the contrary but added that may have misunderstood the findings of the anti-oxidants. "
斯坦普菲尔 also said that the Danish study and will not stop him from intake of vitamin supplements.
Nutrition security in the United States, Vice-Chairman Andrew Shao (Andrew Shao) also pointed out that the Danish study also confused a difference in the prevention and secondary prevention, the former is for the healthy population, which is against the sick group , "the secondary prevention and primary prevention of test results and to draw together the conclusions of the entire population, which is a scientific method." In addition Shao also believe that many previous experiments on the anti-oxidants there are limits.
There are some researchers skeptical about this. United States University of Texas MD Anderson Cancer Center Biostatistics Dean Berry (Donald Berry) believes that the study led him to believe, anti-oxidants do not have the determination of the wholesome role, but he did not agree to take anti-oxidants may increase the death rate conclusions.
Vitamin may bring an "extra risk"
In addition to criticism and doubt, the scientific community, for the study of people who agree with the attitude of a lot of people.
For the critical study of different standards in Denmark, the United States Hopkins University, Miller (E dgarR.Miller) obviously disagree. In his view, there are good clinical studies, there are poor, for they are doing research is a good method, Furthermore, the Danish study and the other one for a large number of women in the study results were consistent. This involved 40,000 healthy women, studies have shown that even subjects without the disease, vitamin supplements do not work.
Miller further pointed out that biologically seemingly supplements are very reasonable, people hope that they will work, but in fact they do not work. "What we need is to focus on improving the lifestyle, such as non-smoking and weight, rather than being deceived to the fantasy, intake of supplements can reduce the risk of death."
A long-standing dispute over the pros and cons
Vitamin healthy or harmful to health has been argued constantly.
Bjelakovic 2004 Serbia and Montenegro either internal medicine professor at the University of Nice, it and several European researchers in the October 2 that year's "The Lancet" magazine published an article saying they were taking the right vitamins 170,000 a comprehensive analysis of 14 trials found that taking vitamins and antioxidants than non-medication of people suffering from the risk of esophageal cancer should be larger.
However, the longest and most heated debate, originated from two famous Nobel Prize-winning chemist Linus Pauling (Linus Pauling). Pauling claimed that vitamin C a large number of healthy and cancer.
Pauling in 1970 published "Vitamin C and the common cold," a book, make a daily vitamin 1000 mg or more of vitamin C can prevent colds. In 1979, Pauling published in cooperation with others, then the "Cancer and Vitamin C", a book recommended that each cancer patient taking 10,000 milligrams or more per day of vitamin C, while he himself is a daily dose of 12,000 mg, because they "believe that this simple method will be very significantly improve the results of cancer treatment."
Pauling's point of view, however, has been questioned. At that time the United States Public Health Foundation, warned: taking 1000 mg or more per day of vitamin C can prevent colds to say the evidence is not sufficient. The American Medical Association also issued a statement: Vitamin C can prevent or treat colds, anti-cancer role of vitamin C unconfirmed.
In the issue of vitamin C, there are some Chinese experts have advocated a higher dose. Well-known biochemist, Nanjing University, Professor Zheng Ji C600 mg vitamin daily for many years, the Chinese Nutrition Society president Professor Ge-woo said in 2003, his daily vitamin C400 mg, and has insisted for 10 years.
Pauling died of prostate cancer at the age of 93. Interestingly, his students Robinson (along with the Pauling founded and served as director of the Linus Pauling Institute of Medicine) in animal experiments when we got to do in order to Pauling recommended dose of vitamin C fed rats, but it is easy for mice suffering from on the cancer.
Long-standing proposal
16th-century Renaissance medicine scientist palasa Er Susi once said that everything with the toxicity, but the number of doses to determine whether it toxic.
In this regard, the U.S. Tufts University, Boston, director of anti-oxidants Laboratory Blumberg (Jeffrey Blumberg) can be described as similar to the views. He said that now recommended doses of anti-oxidants are "perfect reason," taking the recommended amount, there would be no danger.
For a comprehensive study on the JAMA, the Chinese Center for Disease Control and Prevention, Nutrition and food safety researcher Umezu said that she had not seen this document, inconvenience comment. But in terms of anti-oxidants, "vitamin A intake of more than tolerable upper intake level (UL) is toxic, while vitamin E although there is no development of UL value, but can not be taken without restrictions."
Current Pauling Institute of Medicine, biochemist Frey (Balz Frei) advice might be worth pondering. In his view, the Danish Institute are involved in all the original trial have been trying to produce a sick patient (after taking the supplements) to obtain improved results, and therefore these studies are flawed. Most of the original trial in patients suffering from cancer or heart disease. The patient's improvement "may be the result of drug use, but not taking the role of a dietary supplement." He said, "You can not rely on food supplements to eliminate the better years of the long-term impairment." Moreover, "the problem over many years, research has become clear that antioxidant treatment of diseases, and does not work." Anti-oxidants and high mortality rate-related, there may be lies in excess of taking on. Published in the JAMA authors said they surveyed, "the vast majority of the Institute of supplements given to the dose of a balanced diet than the average dose is high and a number of experiments used much higher than the recommended daily dose permitted dose, even to exceed the maximum safe dose level. "
Whether or not to take anti-oxidants, how to take, for this issue is controversial. However, it is worth to emphasize that the United States Association for Cancer Research has always been the suggestion is that through a balanced dietary intake should be an appropriate amount of vitamins and minerals, rather than relying on medication, because the body adapted to the naturally occurring vitamins. Authors also believe that, from vegetables and fruits would be better access to anti-oxidants.
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