Here is some important information from the Tufts Health and Nutrition Update. This latest research shows why it’s important not to overdue it on supplementation of nutrients.
Folic Acid
In further proof that, at least when it comes to nutrition, it’s possible to have too much of a good thing, Norwegian researchers report that high doses of folic acid may increase the risk of cancer. They analyzed long-term results of two clinical trials totaling 6,837 heart patients who were given combinations of folic acid, B12, B6 or placebo to test the lowering of homocysteine, an amino acid in the blood linked to heart disease. Unlike the US, Norway doesn’t fortify foods with folic acid, making it ideal for such a study. When participants were revisited after a total of 77 months, those assigned to supplemental folic acid plus B12 were 21% more likely to be diagnosed with cancer and 38% more likely to die of cancer. Lung cancer was the main driver of the results, suggesting a possible connection with subjects’ smoking history. Supplementation levels were also quite high: double the US RDA for folic acid and a whopping 167 times the RDA for B12. The bottom line, experts commenting on the findings said, is that it’s safest to get your nutrients from food, and that high-dose supplements shouldn’t be relied on to prevent chronic disease. – JAMA
My note: It’s important for women of child-bearing age to get adequate amounts of folic acid (400 micrograms) to prevent birth defects like spina bifida. This can be accomplished by taking a daily multivitamin. See my October Newsletter archived on this site for more information on multivitamins.
Selenium
Supplements got a second blow from a new US study linking high blood levels of selenium to increased levels of unhealthy cholesterol. Scientists compared selenium and lipid levels in the blood of 1,042 participants in a national nutrition survey, 48.2% of whom reported taking dietary supplements. Those with the highest selenium levels averaged 8% higher total cholesterol and 10% higher in non-HDL cholesterol (all except the “good” HDL cholesterol). Researchers said the high selenium levels weren’t exclusively caused by supplementation, but did raise concerns given the recent popularity of selenium supplements, thought to have antioxidant benefits and possible anti-cancer properties: “We believe that the widespread use of selenium supplements, or of any other strategy that artificially increases selenium status above the level required, is unwarranted at the present time.” – Journal of Nutrition
My note: To be on the safe side, don’t exceed 200 micrograms of selenium from supplement sources.
