Vitamin E helps protect against toxic effects of mercury
A combination of vitamin E and selenium products may help reduce the toxicity of mercury from eating fish, according to a recent study involving lab rats. Scientists say that, if results can be replicated in human beings, the findings could mean that pregnant women may be able to consumer larger amounts of fish, and their children benefit more from omega-3s.
The debate between the touted benefits of omega-3 ingestion through oily fish versus the possibility of toxicity from methylmercury is perpetual, say reports. Some researchers have claimed that the benefits far outweigh the risks.
Omega-3 fatty acids have additionally been linked to better development of the fetus, as well as enhanced cognitive function and cardiac health.
Methylmercury (MeHg) is a contaminant that has been found in varying amounts in all fish, but it’s become such a health concern that a joint FAO/WHO (UN Food and Agriculture Organization/World Health Organization) Expert Committee on Food Additives has even established an accepted weekly intake level of 1.6 micrograms per kilogram of body weight.
Selenium and vitamin E together reduced toxicity
As described by the website NutraIngredients.com:
The new study, published on-line in Neurotoxicology and Teratology, divided 75 female rats into five equal groups, each had their normal diet supplement with: nothing (control group), MeHg, MeHg plus selenium, MeHg plus vitamin E, and MeHg plus vitamin E and selenium.
The researchers found that supplementation with both vitamin E and selenium eased the effects of mercury toxicity in the offspring rats.
“[We] found that when selenium and vitamin E were given together MeHg toxicity in adult rats was reduced, and improved growth, fewer clinical signs of toxicity and longer survival time occurred,” lead researcher Peter Beyrouty, of McGill University in Quebec, wrote in an abstract of the study.
Neither selenium nor vitamin E showed much of an effect on survival numbers when supplemented independently, the study found.
And while researchers could not specify a certain triggering mechanism, they nonetheless proposed that it was “possible that vitamin E has more roles than what is currently known.”
Researchers also said that it’s possible the vitamin could have boosted the efficacy of the selenium; previous studies using adult animals demonstrated promising results indicating that selenium by itself could reduce mercury toxicity.
“These results suggest that antioxidant nutrients in the diet may alter MeHg reproductive and development toxicity,” the researchers wrote. “The underlying and human implications warrant further investigations.”
The Environmental Protection Agency has said that one in six pregnant women in the United States have blood mercury levels significant enough to cause fetal damage. That, the agency said, suggests that selenium and vitamin E supplementation might ease the risk for 650,000 babies born every year in the U.S.
Current FDA recommendations are safe
Though the study reported a positive effect for antioxidants that ultimately deserves closer scrutiny, there are limitations, particularly regarding doses utilized:
The amount of MeHg added to the diets in the intervention groups was 1.25 mg per kg per day, giving a daily mercury intake over a thousand times larger than the weekly tolerable intake recommended by the FAO/WHO.
When conducting their research, the team upped the level of supplementation above the human equivalent. Rats were given 225 IU of vitamin E per kilogram of body weight; the recommended daily allowance for an adult human is 10 IU, with an upper safe limit of 900 IU.
Currently, the Food and Drug Administration recommends that pregnant mothers eat no more than two servings of oily fish per week. Most experts believe that that recommendation is safe.
An alternative to eating fresh oily fish would be supplementing with omega-3s, most of which have been subjected to contamination tests.