Why not eat iodine rich foods?

[Guest guest]

I read in Dr. Brownstein's Iodine book that Japanese people who eat a lot of

iodine, about 13.5 mg per day in their diet are healthier and have less diseases

than other Japanese people who eat less and other people who eat less iodine. If

they are eating iodine rich foods that contain iodine naturally then why should

we supplement with iodine and not eat kelp or other seaweeds instead? Wouldn't

food be better than a supplement? The research about iodine is usually based on

people who eat iodine rich diets not people who supplement with iodine, am I

right?

I guess I don't get why we need to take a supplement when we could just add some

kelp to our food.