No more fish for me...

Until I can find convincing evidence that it's not killing my hair.

On other threads I've brought up the paradoxical relationship between selenium-based, sulfhydryl-containing proteins/enzymes (eg., glutathione, cysteine) and mercury toxicity. Since mercury binds to the sulfhydryl groups with high affinity, the sulfhydryl-containing compounds have been claimed to have a protective effect from mercury. But I've come across a number of papers showing that selenium intake actually enhances mercury absorption: the protective effect is achieved because GSH and GPx (glutahione and glutathione peroxidase) actually transport the mercury to less sensitive tissues like muscle, rather than facilitating excretion of the mercury.

Today I found some more information confirming my fears:

Organic mercury can be found in 3 forms, aryl and short- and long-chain alkyl compounds. Organic mercurials are absorbed more completely from the GI tract than inorganic salts are; this is because of intrinsic properties, such as lipid solubility and mild corrosiveness (although much less corrosive than inorganic mercury). Once absorbed, the aryl and long-chain alkyl compounds are converted to their inorganic forms and possess similar toxic properties to inorganic mercury. The short-chain alkyl mercurials are readily absorbed in the GI tract (90-95%) and remain stable in their initial forms. Alkyl organic mercury has high lipid solubility and is distributed uniformly throughout the body, accumulating in the brain, kidney, liver, hair, and skin. Organic mercurials also cross the blood-brain barrier and placenta and penetrate erythrocytes, attributing to neurological symptoms, teratogenic effects, and high blood to plasma ratio, respectively.

The excerpt is from http://emedicine.medscape.com/article/819872-overview.

Methylmercury is the organic form of mercury found in fish. "Alkyl organic mercury" is another name for methylmercury. By eating fish, you'd be dumping a form of mercury with a very high absorption percentage: 90%, as state in the article. Note that this stuff accumulates in your skin...right where your hair follicles are embedded.

So yes, eating mercury-containing fish gives you a huge amount of protective selenium. But as mentioned before perhaps selenium's protective effect from mercury toxicity is due to the fact that sulfhydryl-containing molecules are transporting the mercury away from critical tissues like kidneys and liver to less critical tissues like muscle (and skin!).

I've been eating a lot of salmon mainly for the omega-3. My n6-n3 ratio is going to worsen now..maybe I'll just have to up my krill oil intake to 2+ grams per day.

More proof:

Chenyang Shi*, Alfred T. Lane† and Thomas W. Clarkson*

*Environmental Health Sciences Center, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642 USA

†Department of Dermatology and Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642 USA
Received 10 August 1989.
Available online 4 May 2005.

Human hair has unique advantages in monitoring environmental exposures to methylmercury. Using newborn Balb/c mice as a model system, the incorporation of methylmercury into the hair was studied and compared with methylmercury distributions in other tissues. Newborn mice were given intraperitoneal injections of 203Hg-labeled methylmercury at designated times according to hair growth stages of the mouse. Animals were sacrificed 2 days after dosing. Distribution of mercury in pelt and other tissues was measured. The level of mercury in pelt was found to correlate with hair growth. The amount of mercury in pelt peaked when hair growth was most rapid and the total amount of mercury in pelt was significantly higher than that in other tissues, constituting 40% of the whole body burden. However, when the hair ceased growing, the amount of mercury in pelt dramatically dropped to 4% of whole body burden and mercury concentrations in other tissues except brain were elevated. Autoradiographic studies with tritium-labeled methylmercury demonstrated that methylmercury concentrated in hair follicles in the skin. Within hair follicles and hairs, methylmercury accumulated in regions that are rich in high-sulfur proteins. The uptake of inorganic mercury (administered as HgCl2) by pelt was also compared with that of methylmercury. The amount of inorganic mercury found in pelt was less than one-half that of methylmercury in animals with growing hair. Cessation of hair growth did not decrease the inorganic mercury level in pelt to the same extent as in the case of methylmercury.

1Part of this study was presented at the 28th Annual Meeting of the Society of Toxicology, Atlanta, GA, February 27–March 3, 1989, and was published in an abstract form.

The take away, avoid vaccinations, don't worry about the fish and beware of the dentist.

CS,

The articles that I cited show that the organic form of mercury found in fish (methylmercury) accumulates in the skin and hair follicles to a much greater extent than its inorganic counterparts. While I'm not stating that the inorganic mercury contained in dental amalgams is not toxic, I am saying that the organic mercury found in fish can be more of a disaster for hair.

Most of the inorganic mercury inhaled in the form of vapor accumulates in critical areas like the kidneys, liver, and the CNS. The distribution of organic mercury is much more diffuse...

Sure, methylmercury might be bound to sulfur-containing proteins in the hair follicle, but would you want mercury ions to be sitting around in your hair follicle, waiting to be unbound? I imagine that they would cause a huge increase in oxidative stress for the hair follicle, which would be terrible from an MPB point of view right?

I'm thinking about mega-dosing on krill oil instead of eating fish...

-MP

Despite the recommendations, I've avoided fish for that reason. In fact, I avoid most fatty animal products.

Fish mercury is in organic form and is unactivated due to selenium.

Mercury is most toxic to the brain in its inorganic form

crincrin,

Does your diet have a favorable omega 3-6 ratio? If so, what foods do you eat for EPA/DHA? The ALA found in plant sources like flaxseed, walnuts, broccoli, and green leafy vegetables have not been proven to be as effective as the omega 3s found in animal sources.

It's frustrating that so many foods are abundant in omega 6. If I give up salmon, I doubt my n3:n6 ratio will be much better than 1:10.

-MP

CS, would you say there is any problems with canned fish? Does the can add any metals to it? Is there any fish that should be avoided?

I stay away from canned food in general.

http://articles.mercola.com/sites/articles/archive/2009/11/24/Why-Canned-Soups-Can-Be-Dangerous-to-Your-Health.aspx

Thanks for the link crincrin, I'll stay away from cans.