food

[por 354]

is there a recommended weekly amount of tuna you can eat because i have been told you should only eat one tin a week because of the mercury levels contained in the fish cheers

[makemesmile]

I've heard this said in relation to pregnant women, but not sure how it relates to the non-preggers.

[rhona_j]

I'm not sure of the exact amount, but yes, you should limit the amount you eat.
Apparently since tuna is at the top of the fishy food chain, it eats all the other fish so therefore has high levels of mercury.

[CheekyChops]

Well I'm stuffed then, I eat it on a daily basis!

[nickmo]

Hi P - link with some further info may be of interest http://www.nrdc.org/health/effects/mercury/gui de.asp suggesting contamination levels in seafish.

Also as tuna is becoming an endangered species round the world - Mediterranean as well as Pacific - and that it takes 20 tons of white fish to feed 1 ton of tuna it is gaining in momentum to:

avoid if there is a more sustainable and so preferred alternative to choose; to consider the ethical and ecological impact - dolphin friendly catch etc; to reduce the amount consumed anyway due to the tuna being at the top of the food chain so (as noted) will absorb the prey contents of contaminents.

Fish stocks are the subject of loads of debate and comment but as a percentage of farmed species like salmon can also contain other harmful chemicals like PCBs from water run off etc, be fed antibiotics that stay in the fish, the pollution of the seas is continuing - especially in areas that have high deforestation - chemical run off into water courses leads to the rivers feeding the residues into the seas near fishing grounds etc etc, try to get some sort of clarification for the sellers as to the supply source when buying./

The mercury in the tuna by the way is not the one you find in barometers etc - it is still a harmful chemical and advice is avoid if pregnant or very young, and limit the quantity consumed in any given period.

In the UK the Seafish authority (or at least one of them) has a useful site including certificates of the trawlers that have registered to take up the Responsible Fishing scheme - desgined to ensure both commercialy viable rates for the catch but also be environmentally friendly to the stocks as well. Link at: http://www.seafish.org if you want some info, plus recipes, etc etc.

15:49 Wed 24th Jan 2007

[BBWCHATT]

http://en.wikipedia.org/wiki/Tuna

[lafrancaise]

If you eat a varied diet of all foods there's no problem. it's when you start eating certain foods daily or very often the problems arise. Eat different fresh or frozen fish and from time to time a tin of sardines, mackerel, salmon or tuna for easiness.

[Gef]

nickmo, mercury is mercury. Barometers use the element, its compounds are found in tuna.

[nickmo]

Ok G - correct. To clarify the comment - the mercury present in tuna and other sea fish is unlikely to be a liquid pool of the element that is found in thermometers, barometers, etc. Elemental mercury is the shiny liquid metal or the ore from which it is extracted, so you can't nail a tuna up on the wall and check the daily temperature, etc.

Mercury in all its forms as organic and inorganic, as a compound or as oxides or other compounds - don't know all the terms but web search should give examples - is a toxic material that can cause cancers, kidney failures and loads of other things - Lewis Carroll used the term '...mad hatter...' as mercury (compound) was used in the curing of skins for top hats etc and the degenerative effect of inhaling the stuff when heated sent hat makers slightly off to the side of real life.

Methyl mercury largely from fertilisers used in farming is washed into water courses that then end up in seas. Greater concentration will be found in certain fish species especially those at the top of the food chain - starts in the micro organisms and is ingested up the chain...

On land by the way, mushrooms are known to fix mercury from soil, but you would have to eat considerably more than one or two two to suffer any ill effects..