Clipping Board » Dangerous Medicinal Tonics ─ Nutrients should be moderate in the body—excessive supplementation only becomes a burden.
Lin Jieliang, Professor of Clinical Toxicology, Linkou Chang Gung Memorial Hospital
Although the medical community has not yet reached a consensus on the health-protective effects of antioxidant supplements, many people in Taiwan prefer to take antioxidant vitamins or nutritional supplements—such as vitamin A, C, E, beta-carotene, or selenium—for extended periods, believing they benefit health. Some even assume that higher doses of antioxidants offer greater protective effects, leading to an overabundance of high-dose vitamins and supplements on the market. For some individuals, skipping a few high-potency vitamin pills daily can cause discomfort. Unfortunately, recent medical studies have found that long-term use of antioxidant vitamins or supplements not only fails to help prevent cancer or cardiovascular diseases but may also harm health. Some key studies include:
In 2003, *The Lancet* published an analysis by American researchers of seven large-scale prospective studies on vitamin E and eight on beta-carotene. Each study involved over 1,000 participants, with daily doses of vitamin E ranging from 50 to 800 IU and beta-carotene from 15 to 50 mg, tracked for periods ranging from 1.4 to 20 years. A total of 81,788 participants were involved in the vitamin E trials, and 138,113 in the beta-carotene trials. The results showed that long-term vitamin E use had no effect on preventing overall mortality or cardiovascular and cerebrovascular deaths. Meanwhile, long-term beta-carotene use was associated with a slight but statistically significant increase in overall and cardiovascular mortality.
Similarly, in 2004, *The Lancet* published a Danish study on the effects of antioxidant vitamins in preventing gastrointestinal cancers. The analysis included 14 large-scale prospective studies involving 170,525 participants who took vitamin A, C, E, beta-carotene, or selenium alone or in combination. Among seven high-quality, long-term follow-up studies involving 131,727 participants, long-term antioxidant vitamin or nutrient use was found to slightly but significantly increase mortality by 6%. Notably, beta-carotene combined with vitamin A or E increased mortality risk by 29% and 10%, respectively.
In March 2005, *JAMA* published a seven-year study (1993–1999) by Canada’s McMaster University Population Health Research Institute. The study involved 9,541 participants aged 55 or older with cardiovascular disease or diabetes. One group took 400 IU of vitamin E daily, while the other received a placebo, in a randomized, double-blind trial. Vitamin E not only failed to prevent heart disease or cancer but also increased the risk of heart failure and hospitalization in middle-aged and elderly patients with cardiovascular disease or diabetes. Those taking vitamin E had a 13% higher risk of heart failure and were 21% more likely to be hospitalized than those who did not. The researchers speculated that high-dose vitamin E might interfere with the body’s natural antioxidant functions. They emphasized that the study focused on high-dose vitamin E supplements and that consuming vitamin E-rich foods like green vegetables and nuts remains beneficial.
Similarly, in July 2005, *JAMA* published a 10-year study (1992–2004) by Harvard University. The study involved 39,876 healthy women aged 45 or older, with one group taking 600 IU of natural vitamin E every other day and the other receiving a placebo, in a randomized, double-blind trial. For middle-aged healthy women, vitamin E did not prevent cardiovascular disease, stroke, or cancer. Although it effectively reduced cardiovascular mortality, it did not contribute to a decrease in overall mortality.In fact, no amount of vitamin or nutrient supplements can ever replace the importance of a healthy lifestyle and a balanced diet for overall health. Long-term reliance on varying doses of antioxidant medications may even have negative effects on health. The antioxidants found in fresh fruits, vegetables, and other natural foods are what truly benefit human health. People should aim for a balanced daily intake of natural produce rich in antioxidants, such as vitamin C-packed leafy greens and fruits; vitamin E-rich seeds, germ oils, wheat germ, legumes, and nuts; vitamin A and beta-carotene sources like dark green or orange vegetables and fruits (e.g., spinach, carrots, sweet potatoes, papayas, and mangoes); as well as other healthy foods like tomatoes, soybeans, green tea, onions, and whole grains. Only a healthy lifestyle, balanced diet, and regular check-ups serve as the best defense against heart disease and cancer.
Source: http://www. greencross. org. tw/ food& disease/ anti- oxidant. htm
Long-term Antioxidant Vitamin Use May be Harmful
Although the medical community has not yet reached a consensus on the health-protective effects of antioxidant supplements, many people in Taiwan prefer to take antioxidant vitamins or nutritional supplements—such as vitamin A, C, E, beta-carotene, or selenium—for extended periods, believing they benefit health. Some even assume that higher doses of antioxidants offer greater protective effects, leading to an overabundance of high-dose vitamins and supplements on the market. For some individuals, skipping a few high-potency vitamin pills daily can cause discomfort. Unfortunately, recent medical studies have found that long-term use of antioxidant vitamins or supplements not only fails to help prevent cancer or cardiovascular diseases but may also harm health. Some key studies include:
In 2003, *The Lancet* published an analysis by American researchers of seven large-scale prospective studies on vitamin E and eight on beta-carotene. Each study involved over 1,000 participants, with daily doses of vitamin E ranging from 50 to 800 IU and beta-carotene from 15 to 50 mg, tracked for periods ranging from 1.4 to 20 years. A total of 81,788 participants were involved in the vitamin E trials, and 138,113 in the beta-carotene trials. The results showed that long-term vitamin E use had no effect on preventing overall mortality or cardiovascular and cerebrovascular deaths. Meanwhile, long-term beta-carotene use was associated with a slight but statistically significant increase in overall and cardiovascular mortality.
Similarly, in 2004, *The Lancet* published a Danish study on the effects of antioxidant vitamins in preventing gastrointestinal cancers. The analysis included 14 large-scale prospective studies involving 170,525 participants who took vitamin A, C, E, beta-carotene, or selenium alone or in combination. Among seven high-quality, long-term follow-up studies involving 131,727 participants, long-term antioxidant vitamin or nutrient use was found to slightly but significantly increase mortality by 6%. Notably, beta-carotene combined with vitamin A or E increased mortality risk by 29% and 10%, respectively.
In March 2005, *JAMA* published a seven-year study (1993–1999) by Canada’s McMaster University Population Health Research Institute. The study involved 9,541 participants aged 55 or older with cardiovascular disease or diabetes. One group took 400 IU of vitamin E daily, while the other received a placebo, in a randomized, double-blind trial. Vitamin E not only failed to prevent heart disease or cancer but also increased the risk of heart failure and hospitalization in middle-aged and elderly patients with cardiovascular disease or diabetes. Those taking vitamin E had a 13% higher risk of heart failure and were 21% more likely to be hospitalized than those who did not. The researchers speculated that high-dose vitamin E might interfere with the body’s natural antioxidant functions. They emphasized that the study focused on high-dose vitamin E supplements and that consuming vitamin E-rich foods like green vegetables and nuts remains beneficial.
Similarly, in July 2005, *JAMA* published a 10-year study (1992–2004) by Harvard University. The study involved 39,876 healthy women aged 45 or older, with one group taking 600 IU of natural vitamin E every other day and the other receiving a placebo, in a randomized, double-blind trial. For middle-aged healthy women, vitamin E did not prevent cardiovascular disease, stroke, or cancer. Although it effectively reduced cardiovascular mortality, it did not contribute to a decrease in overall mortality.In fact, no amount of vitamin or nutrient supplements can ever replace the importance of a healthy lifestyle and a balanced diet for overall health. Long-term reliance on varying doses of antioxidant medications may even have negative effects on health. The antioxidants found in fresh fruits, vegetables, and other natural foods are what truly benefit human health. People should aim for a balanced daily intake of natural produce rich in antioxidants, such as vitamin C-packed leafy greens and fruits; vitamin E-rich seeds, germ oils, wheat germ, legumes, and nuts; vitamin A and beta-carotene sources like dark green or orange vegetables and fruits (e.g., spinach, carrots, sweet potatoes, papayas, and mangoes); as well as other healthy foods like tomatoes, soybeans, green tea, onions, and whole grains. Only a healthy lifestyle, balanced diet, and regular check-ups serve as the best defense against heart disease and cancer.
Source: http://www. greencross. org. tw/ food& disease/ anti- oxidant. htm