There is also a widespread claim that too much Iodine will negatively affect your thyroid. All of those claims seem to be rooted in a single experiment that others have reviewed and say it does not support the claim. My own experience and that of the Japanese suggest otherwise too.

There was one cool study that showed the connection between kelp and reduced incidence of breast cancer. It was based on Japanese women whose cancer rates shoot up when the move to the US. The funny part for me was at the end, where they suggest that people don't start eating a lot of kelp because of the high iodine content which has these negative effects. They then proposed further study to see what was in the kelp that prevented cancer. I was just... I dunno. SMH.