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Fish and shellfish are good sources of essential vitamins, such as niacin, and minerals, such as selenium and iodine. Different types of seafood also give different health benefits. Check out the lists below. Oily fish
Although most people should be eating more fish for their health, there are maximum levels recommended for oily fish and crab (and some types of white fish), see How much oily fish? in Oily fish, shellfish and omega 3. Also, again for health reasons, adults should have no more than one portion of swordfish, shark or marlin a week. This is because these fish could contain high levels of mercury. People who eat a lot of fish every week should try to eat as wide a variety as possible not only for good health but also because of concerns about numbers of fish. 'Pregnancy, children and babies' below contains advice about fish for women who are pregnant, breastfeeding or trying for a baby, and for children and babies.
If you take fish liver oil supplements, remember these are high in vitamin A. This is because fish store vitamin A in their livers. Having too much vitamin A over many years could be harmful. If you take supplements containing vitamin A, make sure you don't have more than a total of 1.5mg a day from your food and supplements.
The type of omega 3 fatty acids found in fish (they’re actually called ‘long chain omega 3 polyunsaturated fatty acids’) help prevent heart disease. These fatty acids are also important for women who are pregnant or breastfeeding because they help a baby's nervous system to develop (see Pregnancy, children and babies). Oily fish such as mackerel, sardines, trout, herring and salmon are the richest source of omega 3 fatty acids. The main shellfish sources are mussels, oysters, squid and crab. Some white fish and other shellfish also contain omega 3 fatty acids but not as much as oily fish. You can check which fish are oily and which aren't in the table below. And while you’re looking at the lists, have a think about how many of these fish you usually eat. Why not try eating something different?
| Oily fish | White fish |
|---|---|
|
Anchovies Carp Eel Herring (Bloater) Hilsa Jack (also known as Scad, Horse mackerel and Trevally) Kipper (herring) Mackerel Orange roughy Pilchards Salmon Sardines Sprats Swordfish Trout Tuna (fresh) Whitebait |
Brill Catfish Cod Coley Dab Dover sole Flounder Flying fish Gurnard Haddock Hake Halibut Hoki John Dory Lemon sole Ling Marlin Monkfish Pangas (also known as River cobbler, Basa or Pangasius) Parrot fish Plaice Pollack Pomfret (also known as Butterfish) Red and grey mullet Redfish (also known as Ocean perch or Rose fish) Snapper (also known as Jobfish and Red snapper) Rock salmon/Dogfish (also known as Flake, Huss, Rigg or Rock eel) Rohu (also known as Ruhi) Sea bass Sea bream (also known as Porgy) Shark Skate Tilapia Tuna (canned) Turbot Whiting |
Most people should be eating more oily fish because omega 3 fatty acids are very good for the health of our hearts. However, there are recommendations for the maximum number of portions of oily fish we should be eating each week (a portion is about 140g):
| 2 portions of oily fish | 4 portions of oily fish |
|---|---|
| Girls and women who might have a baby one day | Women who won’t have a baby in the future |
| Women who are pregnant or breastfeeding | Men and boys |
Oily fish can contain low levels of pollutants that can build up in the body. The pollutants found in oily fish include dioxins and PCBs (polychlorinated biphenyls). Dioxins and PCBs tend to be found in all foods containing fats. They have no immediate effect on health, but can be harmful because they build up in our bodies over time. The recommended maximums for oily fish are lower for most girls and women because high levels of dioxins and PCBs in the diet could affect the development of a baby in the future. If a woman changes her diet when she becomes pregnant, or when she starts trying for a baby, this won't change the levels of dioxins and PCBs that are already in her body. So it's a good idea to limit the amount of oily fish eaten from a young age. Omega 3 fatty acids are good for a baby's development so pregnant women shouldn't stop eating oily fish (see Pregnancy, children and babies). So remember, don't give up eating oily fish because the health benefits outweigh the risks as long as you don't eat more than the recommended maximums. Recent surveys have shown that some other fish, as well as brown crab meat, might also have similar levels of dioxins and PCBs as oily fish. These fish are: sea bream, sea bass, turbot, halibut and rock salmon (also known as dogfish, flake, huss, rigg or rock eel). Anyone who regularly eats a lot of fish should consider choosing a wider variety – and avoid eating crab and these five fish too often. Eating a wider variety of fish and shellfish will also help reduce the environmental impact. Also adults should have no more than one portion of swordfish a week. This is because it could contain high levels of mercury.
Around the world, some types of fish, especially in certain areas, are threatened by being over-fished. At the same time, we’re eating more fish and shellfish in this country and across Europe. Fish and shellfish farming (and other types of what are known as ‘sustainable aquaculture’) have a significant role to play in meeting our demand for fish and shellfish, along with fishing at sea. Here are some practical things we can all do when we’re choosing seafood:
If you fancy being adventurous, why not choose some different types of fish and shellfish that you haven’t cooked before? Check out the links below for some ideas on how to go about it:
If you want to make the healthier choice, remember to go for steamed, baked or grilled fish or shellfish, rather than fried because frying makes fish and shellfish much higher in fat, especially if they’re cooked in batter. But this doesn’t mean you need to stop having an occasional portion of fish and chips. If you make your own fish and chips at home or if you love your occasional trip to the fish and chip shop, check out these tips to help make it a healthier choice:
Once you've worked out which types you want to buy, try to remember the following when you’re choosing fish and shellfish:
Once you get it back home, remember:
There are strict rules and monitoring in place that mean all shellfish in the UK should be safe to eat cooked or raw. However, live shellfish such as mussels, clams and oysters can contain harmful viruses and bacteria when eaten raw or without being thoroughly cooked. These shellfish are filter feeders. This means the water they live in passes through them and they filter their food from this water. So any pollution or germs in the water will build up in the shellfish. It's also important to take care how you store, prepare and cook all shellfish. So make sure you follow the advice given above in Buying fish and shellfish and in Storing and preparing fish and shellfish. However, it should be fine to eat all sorts of shellfish that have been thoroughly cooked, because this usually kills any bacteria or viruses in them. Most of the shellfish we eat is cooked first, but oysters are often served raw, so be especially careful when buying and storing oysters. Older people, pregnant women, very young children and people who are unwell might want to avoid eating raw shellfish to reduce their risk of getting food poisoning.
Cooking fish or shellfish doesn't make someone with a fish or shellfish allergy less likely to react. Allergies to fish or shellfish are quite common allergies and can sometimes cause severe reactions. People who are allergic to one type of fish often react to other types as well. Similarly, people who are allergic to one type of shellfish, such as prawns, crabs, mussels or scallops, often react to other types too.
You can eat most types of fish when you're trying for a baby, pregnant or breastfeeding. Eating fish is good for your health and the development of your baby. But you just need to avoid some types of fish and limit the amount you eat of some others. This table shows the maximum number of portions you should have each week for the fish you need to limit.
The figures for tuna are based on tuna steak weighing 140g when cooked or 170g raw and medium-size cans with a drained weight of about 140g per can. Canned tuna doesn't count as oily fish, so you can eat this as well as your maximum two portions of oily fish. If you’re eating canned tuna, don’t pick fresh tuna as your oily fish. And if you eat two tuna steaks in a week, don’t eat any other oily fish that week. When you’re totting up your weekly portions of oily fish, you’ll need to include a few other types of fish (as well as crab) because they might have similar levels of dioxins and PCBs as oily fish. These fish are: sea bream, sea bass, turbot, halibut and rock salmon (also known as dogfish, flake, huss, rigg or rock eel). The limits for shark, swordfish, marlin and tuna are because these fish contain more mercury than other types of fish. The amount of mercury we get from food isn't harmful for most people, but if you take in high levels of mercury when you're pregnant this could affect your baby's developing nervous system. Oily fish are very good for our health, but we need to limit how much we have because they contain pollutants. These pollutants have no immediate effect on health, but can be harmful if they build up in our bodies over time. Omega 3 fatty acids are good for a baby's development so don’t stop eating oily fish. If you change your diet once you’re already pregnant this won't change the levels of the pollutants that are already in your body. You just need to stick to the limits shown in the above table. Unless your GP advises otherwise, you should avoid taking fish liver oil supplements when you’re pregnant or trying for a baby because these are high in vitamin A, which can be harmful to your unborn baby. When you're pregnant you might also want to avoid eating raw shellfish. This is to reduce your chances of getting food poisoning, which can be particularly unpleasant during pregnancy. See the links below for more advice about what foods you should avoid.
Don't give any fish or shellfish to babies younger than six months because these foods can trigger the development of a food allergy at this age. Children should avoid eating any shark, swordfish or marlin. This is because the levels of mercury in these fish can affect the development of children's growing nervous systems. You might also want to avoid giving raw shellfish to babies and children to reduce their risk of getting food poisoning.
Healthy eating tips from Lorraine Kelly and dietitian Nigel Denby...
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