Mercury in fish and male subfertility

In one of my previous post, I mentioned about fish containing dangerous contaminants such as mercury and how it's linked to neurological problems in developing children. Methyl mercury consumption is also linked to shrinking brain cells - which was contrary to what I always hear "Fish is good for the brain"... how much can the benefits of fish consumption outweigh the adverse effects of mercury?

Anyway, I just came across a research article conducted in Hong Kong showing that mercury levels in hair samples was significantly higher in subfertile males.

In general, the researchers found the mean levels of mercury in the hair of 49 fertile males to be 3.33ppm (6ppm is the maximum level acceptable set by WHO). The mecury levels of 117 subfertile males was found to be higher at 4.23ppm.

The researchers also tested the mecury levels of 16 vegetarians (no meat, fish or shellfish) and 7 of them had a mean mercury level of 0.8ppm. The rest of the subjects had mercury levels below the detection limits set by the researchers. Overall, the mean mecury level for the 16 vegetarian subjects was 0.38ppm - which I thought was a huge contrast to even the fertile males. Maybe it could be the other co-occuring contaminants in fish affecting the fertility and not mercury, but on the safe side, best to avoid them all.

We have been told many times the benefits of fish and it's ability to reduce coronary heart disease. However, the report also mentioned that men in Eastern Finland who ate a lot of fish had a higher mortality rate (as shown by another research). It was hypothesized that this could be due to the high mercury levels in fish.

The WHO states that most people get their mercury from fish and shellfish. Maybe it's time to stop fish consumption (or at the very least.. reduce, reduce, reduce).

Research article source:
Dickman MD, Leung CK, Leong MK. Hong Kong male subfertility links to mercury in human hair and fish. Sci Total Environ. 1998 Jun 18;214:165-74.