High levels of mercury in the blood, caused by eating lots of seafood, can cause male infertility. Researchers gave blood tests to 150 infertile couples who were having in-vitro fertilization and 26 fertile couples to find out how much mercury they had in their systems. They were also asked how much seafood they ate, as well as about other sources of mercury, such as fish oil supplements. They found that the infertile group had much higher blood mercury concentrations.

Over one-third of infertile men had abnormally high mercury in their blood, as did 23% of infertile women. Dr. Christine Choy says, “While comparing infertile subjects having abnormally high blood mercury concentrations, seafood consumption was the only different source of exposure to mercury among various other sources.” In other words, it was the fish that made the difference.

The study was carried out in Hong Kong, where people eat a lot of seafood and seas have high levels of pollution. In the U.S., people eat less fish and there?s less pollution, but it could still be a problem

Tuna and swordfish, which prey on other fish, may have especially high concentrations of mercury in them. But Bill Ledger, a U.K. professor of obstetrics and gynecology, says, “You would have to have seafood at least three or four times a week (to get too much mercury in your blood).”

So if you?re trying to have a family, lay off the tuna and fish oil supplements.

How can we find out what?s in the food we eat? Read ?Eating in the Dark? by Kathleen Hart,click here.

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