Tuna and mercury, and green tea!

[Pat Robinson]

"White/albacore tuna in water" contained the highest amount of EPA/DHA (Omega 3 fatty acids) among the canned tuna but mercury levels were four times higher than those in "light tuna in water".

EPA/DHA amounts were higher in salmon and mackerel which contain less mercury than canned tuna product.

This *in vitro* study, looks at "Dietary mercury exposure and effects of foods containing phytochemicals on mercury bioavailability". (basically which foods make you absorb less mercury from food)

Mercury bioaccessibility, significantly reduced in green tea, black tea, soy protein, and sodium copper chlorophyllin (stabilized chlorophyll) in a dose dependent manner, whereas grapefruit juice did not significantly decrease mercury bioaccessibility.

Compared to a control, mercury bioaccessibility with wheat bran, oat bran, and psyllium decreased by 84%, 75%, and 31%, respectively. Cellular mercury uptake was significantly lower in both green and black tea when compared to control (p<0.05).
http://docs.lib.purdue.edu/dissertations/AAI3210789/


Additionally, this extensively referenced and well documented research evaluates many more nutrients and foods and their effect on methylmercury in combination.

Nutrients can also influence the excretion of Hg after exposure to MeHg (Table 10). Rowland et al. (78,88) concluded that dietary fiber such as wheat bran increased the
demethylation rate of MeHg by intestinal flora and increased the fecal excretion of Hg. Se may reduce (199) or increase (302) the excretion of Hg. Nutritional factors may also decrease the excretion of Hg after MeHg exposure. A low protein diet (7.5%) decreased the amount of Hg being excreted into the urine (68).

The search for therapies in chronic MeHg intoxication has led to the suggestion that vitamins or other dietary modifications may enhance the detoxification of MeHg. Megadoses of vitamin B12, folic acid, or amino acids can affect Hg uptake and methylation, though sometimes not in a positive
way. Zorn and Smith (147) reported that vitamin B12 administered alone or with folic acid increased methylation of Hg2+, resulting in increased MeHg levels in the liver.

Megadoses of vitamin B12 administered with vitamin C after exposure to Hg2+ increased MeHg levels in the brain (147). The enhancement of Hg2+ toxicity by vitamin C treatment led to the suggestion that megadoses of vitamin C should be contraindicated among populations with high Hg exposure
(150). (see notated references in link)
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1637774/pdf/envhper0031...


***Much of this is in opposition of my current understanding of the role of B12, folate, and vit C when there are high levels of circulating mercury. Does anyone have more current research references? This study is from the year 2000.

Thanks,

Pat, full of mercury