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Mild cognitive impairment
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- Vitamin E is a fat-soluble vitamin with antioxidant properties. Foods rich in vitamin E include eggs, fruits, green leafy vegetables, meats, nuts and nut oils, poultry, sunflower seeds and oil, olive oil, wheat germ oil, and whole grains.
- Vitamin E comes in 2 types, each of which has 4 forms (isomers): alpha-, beta-, gamma-, and delta-tocopherol; and alpha-, beta-, gamma-, and delta-tocotrienol. So it is actually a combination of 8 subtypes. In humans, the alpha-tocopherol appears to be the most active. Natural vitamin E is labeled with a "d" (e.g., d-gamma-tocopherol), whereas synthetic is labeled "dl" (e.g., dl-alpha-tocopherol).
- Vitamin E is highly susceptible to breakdown due to oxidation or high temperature, so cooking and long storage periods, especially at warmer temperatures, lower the amount of vitamin E in foods.
- The research on Vitamin E has been conducted primarily with the alpha-tocopherol subtype, but natural sources contain just 13% of the alpha subtype, with 60% gamma and a mix of the remaining subtypes. This fact is of significant interest because use of alpha-tocopherol alone, rather than the mixture, may, in large or small part, have contributed to the unexpected lack of benefit observed in preventing heart attacks. Further research is required to clarify this issue.
- In combination with other antioxidants, Vitamin E may lower the risk of macular degeneration.
- Even without proven benefit, many people still take Vitamin E (as alpha-tocopherol) to reduce their risk of heart disease. As explained above, most commercially available Vitamin E consists of alpha-tocopherol alone. Alpha-tocopherol is associated with an increased risk of prostate cancer, so men at increased risk should not take this supplement at all.
- High dose vitamin E may cause a variety of side effects including dizziness, fatigue, headache, weakness, blurred vision, abdominal pain, diarrhea, or nausea.
- Even more concerning, taking alpha-tocopherol for more than 10 years may increase the risk of a particular type of stroke called a hemorrhagic stroke. Daily doses over 400 IU are associated with increased mortality and congestive heart failure.
* *ADVISORY* *
The evidence suggests that regular use of high-dose vitamin E (primarily as alpha-tocopherol) may slightly increase the risk of death from all causes. Therefore, long-term use of alpha-tocopherol is not advised.
CONCLUSION: If you elect to try Vitamin E, remember to include it in your list of medications when you visit your doctor and other health care providers.