|Selenium in Tuna
|Protects Against Mercury
|Yellowfin tuna was first shown in 1972
to protect against mercury toxicity, not
cause it. Further studies by Dr. Howard
Ganther and his team at the University
of Wisconsin led them to conclude that
the rich levels of selenium in tuna were
responsible for the protective effect.
Selenium, an essential element in our diet,
is vital to the body's antioxidant system
and proper immune system function. It
has anti-cancer effects and is known to
detoxify metals including mercury. It has
been shown to protect against mercury in
every animal model tested.
If the ratio of selenium to mercury
determines if a food is safe, what are the
ratios in Hawaii fish? In a Hawaii Seafood
Project study supported by NOAA, Dr.
John Kaneko of PacMar Inc. in Honolulu
and Dr. Nick Ralston of the Energy and
Environmental Research Center in North
Dakota analyzed selenium and mercury in
15 pelagic fish species caught near Hawaii.
They found that all of the tuna and billfish
species and most other pelagic fish species
contained an excess of health promoting
selenium over mercury content. Mako
shark was the only fish in the study that
had more mercury than selenium. For
this reason, most Hawaii fish are not only
a healthy source of high quality protein
and omega-3 fatty acids, they are also
excellent sources of selenium. Our favorite
fish are more likely to protect against
mercury toxicity, than cause it. The good
news for Hawaii seafood lovers-the
selenium is in every bite!
||Regardless of the amount of mercury, if the selenium level is higher,
the fish is safe to eat. In the above figure, molar concentrations of
mercury and selenium in 15 Hawaii fish species are expressed as
means +/- standard deviations.
Reprinted from "Pacific
Islands Fishery News", Winter 2008
Newsletter Of The Western Pacific Regional Fishery Managment Council
J. John Kaneko * Nicholas V. C. Ralston