Reports from Japan say that this week, two sushi bar owners paid £70,000 for a rare bluefin tuna… at least ten times the average price! The 128kg (282lb) Japanese Bluefin is the most expensive sold at Tokyo’s famous Tsukji fish market in nearly a decade. As a huge fan of sushi and sashimi, I would love to have the chance to try some of this… but by the time that this post is published the tuna will have been consumed by some very satisfied customers. It makes me want to jump on the next plane to Tokyo to feast on the sights, sounds and of course try many of the fishy delights to be had in the craziness of Tsukji fish market, Billingsgate it ain’t…
A shoal of Pacific Bluefin tuna
So why is Bluefin tuna so prized in Japan?
Pacific bluefin tuna, are also known as ‘black diamonds’ in Japan due to their scarcity. Commercial overfishing has caused a rift between those fishing sustainably with ‘ippon-zun’ (single hook hand-line fishing) methods and trawler fleets that are plundering the dwindling stocks to near extinction.
Over 2,300, mainly frozen, tuna pass through the Tsukiji fish market daily, illustrating the Japanese love affair with the fish and the reason for the demand. The nation consumes over 600,000 tonnes of tuna each year. Worldwide stocks are so low that quotas are being strictly enforced from the Med to India and coupled with high fuel prices and lower profit margins makes it more compelling to take larger numbers of Bluefin from Japan’s water. Oma, the best place in Japan to land the finest quality Bluefin… the annual catch of 2,500 fish brings approx. 1.6 billion Yen to the local economy. However, the levels are now so low that a haul of six tuna is a rarity!
What are the benefits of tuna?
Bluefin tuna is a carnivorous fish that feeds on smaller fish, krill, red crab and squid. They can grow to 3m (10ft) in length and can weigh up to 550kg (1,200lb). Unlike most fish, the tuna can regulate its body temperature allowing it to be less selective in its range because of different water temperatures. Additional heat to the muscles gives tuna the extra power it needs to hunt food in the form of squid, herring, mackerel that slower predators can not capture. It is these fish that provide the tuna with its prized omega 3 oils EPA & DHA – polyunsaturated oils which are essential for human health and development. Smaller oily fish such as mackerel, herring and sardines accumulate these oils by consuming microalgae that produce these fats.
Fish oils are beneficial for many areas of the body including:
- Reducing cholesterol and may reduce the risk of heart disease
- Anti-inflammatory effect through out the body
- Maintaining cell membrane integrity, allowing the ebb and flow of nutrients and toxins in and out of cells respectively
- Key nutrient in nervous system performance
- Key in brain performance and reduction of symptoms of depression and anxiety
- Stimulates blood circulation
Due to the position of tuna at the top of the food chain, the oil levels are higher due to the consumption of the lesser chain species. Unfortunately this means that tuna and other carnivorous fish such as salmon, swordfish and shark contain high levels of toxic contaminants such as mercury, dioxin and PCBs.
The levels do vary between varieties for example; herring, which resides in the sea, was found to have higher levels than the river-dwelling trout. However, the Foods Standards Agency have stated that women of child-bearing age should only eat two portions per week, whilst men can eat up to four portions per week. Fish oils have a beneficial effect on the neurological development of a foetus so the FSA suggests eating oily fish in moderation however, to avoid shark, marlin and swordfish and not to eat tuna more than once a week.
… TOP TIP… unfortunately tinned tuna doesn’t give us any beneficial oils as the oil is removed during the processing. Tinned sardines, mackerel and herring (and the dreaded anchovy ;-)) are widely available and are full of beneficial oils. Ideally choose tinned fish in either tomato sauce or olive oil if possible. Sunflower and other vegetable oils are prone to oxidation and can become pro-inflammatory and brine has added salt to the fish which is not required.
And remember… check the ingredients, avoid brands that have lots of added extras (such as salt and preservatives).
Easy ways to add oily fish into the diet:
The following recipe is an update on a childhood fave, great for a quick breakfast or lunch. Simple and effective it can be made as easily in the office as it can at home. Containing lots of protein, it will give you a prolonged energy boost that should help balance your blood sugar levels and avoid tiredness dips mid-morning or afternoon.
Sardines on toast:
1 tin sardines in olive oil
2 slices of wholewheat, rye or sourdough bread
1 tbsp Humus
sprinkle of chili powder
Spring onions for garnish
splash of olive oil
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Toast the bread and drizzle with a little olive oil (1tsp)
Drain and in a separate bowl, mash-up the sardines with a fork, adding a sprinkle of chilli
Thinly slice the tops of the spring onions for garnish
Split the sardines between the toast, put half of the humus on each of the slices and sprinkle spring onions on top.
[You can substitute the sardines for mackerel, herring or salmon as you wish].
Add something extra to your soup…
If you fancy a soup for lunch, try adding a tin of mashed-up oily fish (mackerel, sardines, herring, anchovies, salmon) to a vegetable soup. Strange as it sounds, its a nice addition that has the benefit of increasing your protein and essential fat levels really easily. However, make sure you add the fish AFTER you’ve warmed the soup as the oils are very fragile and can become damaged if heated becoming useless to the body. Avoid overcooking soup, it should be hot, not boiling.
Enjoy!
