Fish is such a nutritious, versatile and delicious ingredient. I love how simple it is to make into a super healthy and quick meal – just a few minutes baked in the oven or under the grill, a squeeze of lemon and some steamed vegetables on the side. Perfect.
Even better is that as well as being one of the best sources of omega-3 fatty acids we find in nature, seafood can also provide us with a source of great quality protein, vitamin D, iodine, potassium, iron, zinc, selenium and a few B vitamins. Smaller fish, like sardines, whitebait or anchovies can also give us a useful source of non-dairy calcium.
So what are the healthiest types of fish to eat?
All fish can be healthy in moderation, but sadly, our seas are not as clean as they once were. I would therefore be careful not to eat the larger predator fish too often, as the contamination of pollutants and heavy metals (such as PCBs, pesticides, plastic micro-particles and mercury) in fish increases as you move up the food chain. These include swordfish, shark, marlin and even tuna. Farmed fish also tends to be slightly higher in pollutants than wild fish. Interestingly, one study even found that the level of pollutants in salmon steak was highest at the head end and central section, but lowest at the tail, and avoiding eating the skin resulted in around a further 10% reduction (1).
I would also try not to rely too much on smoked, tinned or cured fish, as it is generally best to stick to unprocessed foods as much as possible, plus they can also be very high in salt.
But wild smaller fish, particularly the oily ones, such as unsmoked mackerel or sardines could be enjoyed twice a week, plus maybe another portion of white fish, for a thyroid-healthy boost of iodine. There are separate guidelines for pregnancy (see the link below for more information);
What flavours work best with fish?
I think the classic flavour combinations have stood the test of time because they work so well. Lemon, fennel, fresh green herbs, olives, tomatoes, pesto, chilli, olive oil, black pepper – they are all easily available and can transform a simple piece of fish into a tasty dish in no time. But some more unusual flavours I have been experimenting with include saffron (delicious made into a sauce), sumac, preserved lemon and smoked paprika. I suppose it is just a case of giving it a go, and finding new combinations that you enjoy.
Top tips for cooking fish
- Try to buy the freshest fish you can get your hands on, and if at all possible, cook it the same day. I was always advised to try to avoid buying fish on a Monday too – as often it is caught the Friday previously, so is already 3 days old!
- If fresh fish is hard to get hold of though, then white fish tends to freeze a bit better than oily fish.
- If you are oven-baking, try to make a parcel out of baking paper to cook your fish in. This keeps lots of the moisture, flavour and juice around the fillet, and really helps to stop it from drying out.
- Always use a timer! I find it so easy to get distracted in the kitchen, and then all of a sudden it’s overdone. So a timer, set a couple of minutes less than the recipe states, means that I can quickly check how things are coming along. You are aiming at the point just as the flesh starts to turn opaque, and then you can take it out of the oven.
- Don’t forget that your fish will continue to cook a bit, even after you have taken it out of the oven.
- Overcooked fish can be quite tasteless, dry and rubbery. Not an enjoyable eating experience! One sign that this might be happening is that you may see lots of white, foamy liquid coming out of the fish. This is harmless albumin, and even perfectly cooked fillets will have a bit, but if there is a lot then it suggests that the temperature is too high and would benefit from being turned down a little.
- If you need to substitute an oily fish in a recipe (such as salmon or mackerel) for a lean fish (generally the white fish – things like haddock and cod), you might want to add something to help baste the fish as it cooks, like a few slices of fresh tomato, some lemon juice or a drizzle of olive oil to prevent it from drying out.
(1) Bayen, S., Barlow, P., Lee, H.K. and Obbard, J.P. (2005) ‘Effect of cooking on the loss of persistent organic pollutants from salmon’, Journal of Toxicology and Environmental Health, Part A, 68(4), pp. 253–265.