Melody
May 2nd 2007, 02:30 PM
I didn't expect to find any nutrition news in this article, but one of the surprises in their research made me start to ponder the importance of Selenium in the diets of fish. This study is in the marine environment, and indicates a very high Selenium content in Plankton. Plankton is, of course, at the bottom of the food chain.
Another important finding described in the paper is the prominent role that the element selenium plays in Ostreococcus. Humans require selenium in small amounts and most people have roughly 25 selenium proteins. Tiny Ostreococcus organisms were shown to have up to 21 selenium proteins, an enormous number relative to their small genome and microscopic size.
Palenik believes this may be because selenium enzymes are some 10- to 50-times more efficient than similar enzymes that don't use selenium. Based on their size, such efficiency is important to help conserve resources such as nitrogen.
"We may need to think more about how selenium helps drive the health of the oceans," said Palenik. "It's a nutrient element that we don't understand very well and now we have evidence of a group of organisms that clearly use it intensively. We may need to think about how this is affecting primary production in the oceans." ~ First Genome Comparison of Plankton Species Yields Surprises Underlying Key Ocean Processes. Underwater Times.
Selenium is a mineral, considered a trace mineral in humans but apparently more of a macromineral in some of our sea-loving fish friends. The Selenium is incorporated into proteins to make Selenoproteins, which are important antioxidant enzymes. They impact immunity, cell regeneration and are thought to impact male fertility. Its relation to virus activity is also being studied with great interest:
Laboratory studies at the University of North Carolina at Chapel Hill first suggested that selenium is the switch that triggers a Jekyll-and-Hyde personality in viruses. Subsequent studies at the University of Georgia in Athens indicated that selenium depletion in a cell may be what throws a switch on HIV, the virus that causes AIDS, and launches that particular viral terrorist on a cellular rampage that wipes out its human host. The irony is that the virus intends no harm. It is simply looking for more selenium. ~ MotherNature.com
If that wasn't enough, it also binds with toxic substances, such as arsenic and mercury, rendering them less harmful
Selenium content can vary greatly in plants as the selenium is taken from the soil. These foods are recognized as good sources of Selenium:
Tuna
Cod
Lobster
Clams
Crabs
Garlic
Eggs
Natural Grains
Although yeast is often used as a source of Selenium in fish food, it is not often organic Selenium. A study conducted in 1995 suggested that the organic forms of selenium increased blood selenium concentration to a greater extent than inorganic forms. Further, a UK study showed that the mean absorption of selenium from fish was 85-90 per cent, compared with 50 per cent from yeast. As per usual, natural sources are best.
Selenium can be toxic if overdosed, so I'm not suggesting that you start plugging it to your fish in copious amounts. However, the importance of it has been largely minimized based on human studies. It is a mineral to at least be more aware of, and we should entertain the real possibility that fish require more than we do.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sources:
Wetlines
DLO-Netherlands Institute for Fisheries Research (RIVO)
http://ods.od.nih.gov
MotherNature.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
© Please note: While you are welcome to link directly to this thread, the contents are copyright CanadianAquariumConnection.com and cannot be copied (all or in part). Thank you for respecting the effort that we have put into our content.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Another important finding described in the paper is the prominent role that the element selenium plays in Ostreococcus. Humans require selenium in small amounts and most people have roughly 25 selenium proteins. Tiny Ostreococcus organisms were shown to have up to 21 selenium proteins, an enormous number relative to their small genome and microscopic size.
Palenik believes this may be because selenium enzymes are some 10- to 50-times more efficient than similar enzymes that don't use selenium. Based on their size, such efficiency is important to help conserve resources such as nitrogen.
"We may need to think more about how selenium helps drive the health of the oceans," said Palenik. "It's a nutrient element that we don't understand very well and now we have evidence of a group of organisms that clearly use it intensively. We may need to think about how this is affecting primary production in the oceans." ~ First Genome Comparison of Plankton Species Yields Surprises Underlying Key Ocean Processes. Underwater Times.
Selenium is a mineral, considered a trace mineral in humans but apparently more of a macromineral in some of our sea-loving fish friends. The Selenium is incorporated into proteins to make Selenoproteins, which are important antioxidant enzymes. They impact immunity, cell regeneration and are thought to impact male fertility. Its relation to virus activity is also being studied with great interest:
Laboratory studies at the University of North Carolina at Chapel Hill first suggested that selenium is the switch that triggers a Jekyll-and-Hyde personality in viruses. Subsequent studies at the University of Georgia in Athens indicated that selenium depletion in a cell may be what throws a switch on HIV, the virus that causes AIDS, and launches that particular viral terrorist on a cellular rampage that wipes out its human host. The irony is that the virus intends no harm. It is simply looking for more selenium. ~ MotherNature.com
If that wasn't enough, it also binds with toxic substances, such as arsenic and mercury, rendering them less harmful
Selenium content can vary greatly in plants as the selenium is taken from the soil. These foods are recognized as good sources of Selenium:
Tuna
Cod
Lobster
Clams
Crabs
Garlic
Eggs
Natural Grains
Although yeast is often used as a source of Selenium in fish food, it is not often organic Selenium. A study conducted in 1995 suggested that the organic forms of selenium increased blood selenium concentration to a greater extent than inorganic forms. Further, a UK study showed that the mean absorption of selenium from fish was 85-90 per cent, compared with 50 per cent from yeast. As per usual, natural sources are best.
Selenium can be toxic if overdosed, so I'm not suggesting that you start plugging it to your fish in copious amounts. However, the importance of it has been largely minimized based on human studies. It is a mineral to at least be more aware of, and we should entertain the real possibility that fish require more than we do.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sources:
Wetlines
DLO-Netherlands Institute for Fisheries Research (RIVO)
http://ods.od.nih.gov
MotherNature.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
© Please note: While you are welcome to link directly to this thread, the contents are copyright CanadianAquariumConnection.com and cannot be copied (all or in part). Thank you for respecting the effort that we have put into our content.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~