After a short journey into one of the fish markets in Tehran over the weekend, I wanted to say a few things about buying and eating fish in Iran.
Fish Market, Downtown Tehran
My starting point is that I had fabulous fish and chips for the first time since arriving in Iran, Home-made. We feasted on excellent saltwater fish, in this case a fish called ‘Hamour’. Hamour is a sub-species of grouper and, in Iran, these come from the Persian Gulf.
Sources and Types of Fish
I make out there to be three main sources of fish in Tehran: the Caspian Sea, the Persian Gulf, and fish farms. I leave out the frozen fish from, for example, Vietnam, as I think they are really pretty lousy. I won’t talk either about farm fish, as I have not had it yet and could not find any studies about fish farm health in Iran. I understand aquaculture is on the increase in Iran, so it might be worth visiting that subject in a later post.
The Caspian Sea (both a huge lake and a small sea!) is a popular seaside destination for Iranians, comprising the northern coastline of Iran, and a great deal of fish in Iran comes from this fishery. Kutum (the most popular fish in Iran), Kafal, tench (or Doctor Fish), Caspian salmon (actually a trout), sturgeon, common carp, and sabre carp are among the three most consumed fish from the not-very-saline (about a third of salt levels of most sea-waters) Caspian.
The saltwater fish of the Persian Gulf (a particularly salty bit of water, by the way), which comprises the southwest coastline of Iran, of which the king is called Hamour (a Grouper), are consumed widely in Iran and feature in fish markets in Tehran. And they are very good eating. Other popular Persian Gulf fish consumed in Iran include rabbit fish, mackerel, and both black and yellow-fin sea bream.
Health Notes for both Persian Gulf and Caspian Sea fish
All four of the main heavy metal levels (cadmium, mercury, copper, and lead) in Persian Gulf fish have been found in several studies to be within permissible levels for consumption. A 2009 study by the School of Pharmacy in Mashhad, Iran, found mercury levels in all fish species tested (anchovy, carp, shark etc) were found to be high, but still below the permissible levels set by the WHO/FAO for mercury intake.
It was noted in one study that the heavy metal content for Pelagic species (those that roam the oceans such as tuna and mackerel) in the Persian Gulf is higher than for those locked into the gulf. Reef fish, for example, from the Persian Gulf seem to be a good eat.
Overall, however, metal levels are still high enough for it to be recommended that Persian Gulf fish be consumed in moderation.
Caspian Sea fish are, however, another story.
The level of four heavy metals cadmium (Cd), copper (Cu), lead (Pb) and mercury (Hg) in the flesh of some of the most commonly consumed fish (kutum, carp, tench, and kafal) from the fishery, as well as water samples (90 each), collected from six different sites of southern Caspian Sea were evaluated by several Iranian studies over time.
There were noteworthy findings for those eating fish in Tehran.
The heavy metal levels in the fish most often consumed from the southern Caspian Sea fishery are significantly higher in the fish than in the water (because of bio-accumulation), and they are at unacceptable levels for human consumption. On my reading of the literature, cadmium, lead, and mercury levels are beyond the WHO/FAO permissible limits. Copper levels were at ‘action’ level in 2011.
The studies overall recommend that intake of Caspian Sea fish be extremely limited. In particular, people under 60kg (children, for instance) and pregnant woman, should avoid Caspian Sea fish to militate against the accumulative toxicity of heavy metals.
Eat only saltwater Persian Gulf fish when staying for prolonged periods in Iran. Eat fresh hamour, if you get the chance while in Tehran!
If just visiting, the intake of heavy metals likely not to be an issue, even if plucked from the Caspian Sea.
Some further reading on this:
1. “Levels of some heavy metal concentration in fishes tissue of southern Caspian Sea”, Mehdi Zarei, Asad Asadi, and Shekofeh M. Zarei, Khorramshahr University of Marine Science and Technology, Faculty of Marine Science,Department of Marine Biology, Iran. August, 2011
2. Toxicology and Industrial Health. 2010 Nov 26 (10): 649-56. “Heavy metals (Zn, Pb, Cd and Cr) in fish, water and sediments sampled from Southern Caspian Sea, Iran”. Tabari S, Saravi SS, Bandany GA, Dehghan A, Shokrzadeh M.
3. Toxicological & Environmental Chemistry, Volume 92, Issue 6, 2010 “Exposure assessment for mercury from consumption of marine fish in Iran”, S.A. Moallema, G. Karimia*, M. Hasanzadeh Khayyatb, M. Bozorgia, A. Nili-Ahmadabadia & F. Nazaria.