Clipping Board » Dangerous Medicinal Tonics ─ Nutrients should be moderate in the body—excessive supplementation only becomes a burden.
2006.05.29 China Times by Lin Jieliang
Although the medical community has not yet reached a consensus on the health-protective effects of antioxidant drug supplements, many people in our country enjoy taking antioxidant vitamins or nutritional supplements, such as vitamin A, C, E, beta-carotene, or selenium, believing they are beneficial to health. Some even think that the higher the dose of antioxidant drugs, the greater the protective effect, leading to a market flooded with high-dose vitamins or nutritional supplements. Some people even feel unwell if they don't take a few high-unit vitamins daily.
However, recent medical research has found that long-term use of antioxidant vitamins or nutritional supplements may not only fail to help people fight cancer or prevent cardiovascular diseases but could also be harmful to health. Some of the more significant studies include:
Long-term use of beta-carotene may be harmful
In 2003, The Lancet published an analysis by American scholars of 7 vitamin E and 8 beta-carotene large-scale prospective studies, each involving more than 1,000 participants. Participants took daily doses of 50 to 800 units of vitamin E and 15 to 50 mg of beta-carotene, with follow-up periods ranging from 1.4 to 20 years. A total of 81,788 participants were involved in the long-term vitamin E trials, and 138,113 in the beta-carotene trials. The results showed that long-term use of vitamin E had no effect on overall mortality or the prevention of heart and cerebrovascular mortality. In contrast, long-term use of beta-carotene slightly but significantly increased overall and cardiovascular mortality.
Similarly, in 2004, The Lancet published a study by Danish scholars on the effect of antioxidant vitamins on preventing gastrointestinal cancers, analyzing 14 large-scale prospective studies involving 170,525 participants. Participants took single or combined doses of vitamin A, C, E, beta-carotene, or selenium daily. In the analysis of 7 high-quality long-term follow-up studies involving 131,727 participants, it was found that long-term use of antioxidant vitamins or nutrients slightly but significantly increased mortality, with a 6% increase in the risk of death. Particularly, the combination of beta-carotene with vitamin A or E increased the risk of death by 29% and 10%, respectively, which was especially notable.
Vitamin E may accelerate heart failure
In March 2005, the Journal of the American Medical Association (JAMA) published a 7-year study (1993-1999) by the Population Health Research Institute at McMaster University in Canada. The study included 9,541 participants aged 55 and older with cardiovascular disease or diabetes. One group took 400 international units of vitamin E daily, while the other group took a placebo, in a randomized, double-blind trial.
Vitamin E not only failed to prevent heart disease or cancer but also increased the incidence and hospitalization rates of heart failure in middle-aged and elderly patients with cardiovascular disease or diabetes who took high doses of vitamin E. Those taking vitamin E had a 13% increase in heart failure and a 21% higher hospitalization rate compared to those who did not take it. Researchers speculated that high doses of vitamin E might interfere with the body's natural antioxidant functions. They emphasized that this study focused on high-dose vitamin E and that consuming green vegetables and nuts rich in vitamin E is still beneficial for health.
Similarly, in July 2005, JAMA published a 10-year study (1992-2004) by Harvard University in the United States. The study included 39,876 healthy women aged 45 and older. One group took 600 units of natural vitamin E every other day, while the other group took a placebo, in a randomized, double-blind trial.For middle-aged healthy women, vitamin E cannot prevent cardiovascular diseases, stroke, or cancer. Although it effectively reduces cardiovascular mortality, it does not help in reducing overall mortality.
Antioxidant components are best obtained from natural sources.
In fact, various vitamin and nutrient supplements can never replace the importance of a healthy lifestyle and a balanced diet for health. Long-term reliance on different doses of antioxidant medications may have negative effects on health. The antioxidant components found in fresh fruits, vegetables, and other foods are truly beneficial to human health.
People should consume a balanced amount of natural fruits and vegetables rich in antioxidants daily, such as vitamin C-rich greens and fruits; vitamin E-rich seeds or germ oils, wheat germ, beans, and nuts; vitamin A and β-carotene-rich dark green or yellow vegetables and fruits like spinach, carrots, sweet potatoes, papayas, and mangoes; and other healthy foods like tomatoes, soybeans, green tea, onions, and whole grains. Only a healthy lifestyle, balanced diet, and regular check-ups are the best choices for preventing heart disease and cancer.
(Author Lin Jieliang is the Director of the Toxicology Department at Linkou Chang Gung Hospital)
Source: http:/ / news. chinatimes. com/ C……0510+112006052900168,00. html
Excessive Antioxidant Intake: Harm before Benefit
Although the medical community has not yet reached a consensus on the health-protective effects of antioxidant drug supplements, many people in our country enjoy taking antioxidant vitamins or nutritional supplements, such as vitamin A, C, E, beta-carotene, or selenium, believing they are beneficial to health. Some even think that the higher the dose of antioxidant drugs, the greater the protective effect, leading to a market flooded with high-dose vitamins or nutritional supplements. Some people even feel unwell if they don't take a few high-unit vitamins daily.
However, recent medical research has found that long-term use of antioxidant vitamins or nutritional supplements may not only fail to help people fight cancer or prevent cardiovascular diseases but could also be harmful to health. Some of the more significant studies include:
Long-term use of beta-carotene may be harmful
In 2003, The Lancet published an analysis by American scholars of 7 vitamin E and 8 beta-carotene large-scale prospective studies, each involving more than 1,000 participants. Participants took daily doses of 50 to 800 units of vitamin E and 15 to 50 mg of beta-carotene, with follow-up periods ranging from 1.4 to 20 years. A total of 81,788 participants were involved in the long-term vitamin E trials, and 138,113 in the beta-carotene trials. The results showed that long-term use of vitamin E had no effect on overall mortality or the prevention of heart and cerebrovascular mortality. In contrast, long-term use of beta-carotene slightly but significantly increased overall and cardiovascular mortality.
Similarly, in 2004, The Lancet published a study by Danish scholars on the effect of antioxidant vitamins on preventing gastrointestinal cancers, analyzing 14 large-scale prospective studies involving 170,525 participants. Participants took single or combined doses of vitamin A, C, E, beta-carotene, or selenium daily. In the analysis of 7 high-quality long-term follow-up studies involving 131,727 participants, it was found that long-term use of antioxidant vitamins or nutrients slightly but significantly increased mortality, with a 6% increase in the risk of death. Particularly, the combination of beta-carotene with vitamin A or E increased the risk of death by 29% and 10%, respectively, which was especially notable.
Vitamin E may accelerate heart failure
In March 2005, the Journal of the American Medical Association (JAMA) published a 7-year study (1993-1999) by the Population Health Research Institute at McMaster University in Canada. The study included 9,541 participants aged 55 and older with cardiovascular disease or diabetes. One group took 400 international units of vitamin E daily, while the other group took a placebo, in a randomized, double-blind trial.
Vitamin E not only failed to prevent heart disease or cancer but also increased the incidence and hospitalization rates of heart failure in middle-aged and elderly patients with cardiovascular disease or diabetes who took high doses of vitamin E. Those taking vitamin E had a 13% increase in heart failure and a 21% higher hospitalization rate compared to those who did not take it. Researchers speculated that high doses of vitamin E might interfere with the body's natural antioxidant functions. They emphasized that this study focused on high-dose vitamin E and that consuming green vegetables and nuts rich in vitamin E is still beneficial for health.
Similarly, in July 2005, JAMA published a 10-year study (1992-2004) by Harvard University in the United States. The study included 39,876 healthy women aged 45 and older. One group took 600 units of natural vitamin E every other day, while the other group took a placebo, in a randomized, double-blind trial.For middle-aged healthy women, vitamin E cannot prevent cardiovascular diseases, stroke, or cancer. Although it effectively reduces cardiovascular mortality, it does not help in reducing overall mortality.
Antioxidant components are best obtained from natural sources.
In fact, various vitamin and nutrient supplements can never replace the importance of a healthy lifestyle and a balanced diet for health. Long-term reliance on different doses of antioxidant medications may have negative effects on health. The antioxidant components found in fresh fruits, vegetables, and other foods are truly beneficial to human health.
People should consume a balanced amount of natural fruits and vegetables rich in antioxidants daily, such as vitamin C-rich greens and fruits; vitamin E-rich seeds or germ oils, wheat germ, beans, and nuts; vitamin A and β-carotene-rich dark green or yellow vegetables and fruits like spinach, carrots, sweet potatoes, papayas, and mangoes; and other healthy foods like tomatoes, soybeans, green tea, onions, and whole grains. Only a healthy lifestyle, balanced diet, and regular check-ups are the best choices for preventing heart disease and cancer.
(Author Lin Jieliang is the Director of the Toxicology Department at Linkou Chang Gung Hospital)
Source: http:/ / news. chinatimes. com/ C……0510+112006052900168,00. html