Wednesday, January 28, 2015

Why don't fish have mercury issues?

Why don't fish suffer from mercury?

One of the most comprehensive studies ever done of the effect of eating fish was done in the Seychelles, an Island nation in the Indian Ocean off the east coast of Africa. Over 1500 women and their children were studied over 25 years by a group of researchers from  universities and the Seychelles government. These were women who ate fish up to 10 times per week or more, and suffered no ill effects. And the more fish they ate, the smarter their kids were. Here is an excerpt from a recent article in netdoctor:

'Researchers at the University of Rochester, Ulster University and the Republic of Seychelles Ministry of Health and Ministry of Education analysed data from the Seychelles Child Development study.
The 89,000 residents of the Seychelles islands in the Indian Ocean eat ten times more fish than those in the US or Europe.
Over 1,500 mothers and children took part in the study. The researchers assessed child development through a series of communication, behaviour and motor skills tests from 20 months of age until the children were in their 20s.
Hair samples were also collected from the mothers during pregnancy so that the levels of mercury exposure could be measured.
No association was found between fish consumption among pregnant mothers and impaired childhood development.
However, the children of mothers with higher levels of omega-3 - the fatty acid found in fish - performed better on some tests than those whose mothers had low levels of omega-3.
Philip Davidson, lead researcher of the study, said: 'It appears that the relationship between fish nutrients and mercury may be far more complex than previously appreciated.

In other words, eating lots of fish when you're pregnant is good for both the mother and her unborn baby. So why have there been so many scary articles about mercury in fish? The fish don't suffer from being exposed to the minute amounts of mercury in the environment, so why should we be so worried?

The big mercury poisoning scare started many decades ago when there was a huge industrial mercury spill off the coast of Japan. The fish were sickened, and so were the people who ate them. The big difference? The amounts of mercury were massive, too great for the fish to survive.

Scientists have long known that the small amount of environmental mercury that is absorbed by fish chemically combines with selenium in the fish's system, causing it to become non-detrimental to the fish. Many scientists also believe that it makes it non-detrimental to humans.

So why all the scare stories? The US Government, when setting standards for mercury, chose to use a study done on the Faeroe Islands near Scotland where the natives eat a lot of whale. Unlike fish, whales (mammals, not fish) live for decades, and store all kinds of nasty pollutants in their blubber, which these people ate. There wasn't any mercury in the fish they ate, only in the whale blubber, and yet this is the study that the politicians chose to use for setting standards for how much fish we should eat. The scientists wanted them to use the Seychelles Study, where the people actually ate fish all the time, but the pols picked the whale study.

So how much whale blubber do you eat?

Since the mercury in our oceans comes from industrial emissions, I find it somewhat strange that all the focus is on fish - surely these emissions are getting into all of our food, especially in areas where power plants are spewing it out all the time. Who is testing the beef and chicken for mercury? How about the food crops grown on farms near power plants and factories?

The cattle industry in the US has a great deal of political clout, much more than the seafood industry. I'm guessing that they help promote all the mercury-in-fish hype. If beef is good for you, why is it that in Japan, where heart disease was almost non-existent because of high fish consumption, became a growing problem when the western diet of red meat and processed foods was introduced after World War II? Heart disease is the biggest killer in the US, for both men and women - we could lower our medical costs and extend our lives if we ate like the ladies in the Seychelles. There have been no confirmed cases of mercury poisoning in the US, but there sure are a lot of heart attacks. Maybe we should eat more fish.

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