We all know fish and seafood can be good for us, but which ones should we be eating and why? From brain boosts to staving off depression, Abi Jackson scales through the ocean's superfoods

SALMON

Often hailed as one of the healthiest foods in the world, salmon boasts endless vitality-boosting benefits. Firstly, it's a good source of lean protein, which helps keep you feeling full for longer, supports muscle growth and repair and boosts metabolism, making it great for helping maintain a healthy weight. Secondly, it's packed full of nutrients, like omega 3 fatty acid - known, among other things, to promote heart and brain health - and iron, calcium and selenium, which has antioxidant properties, meaning it could help protect against certain cancers and support healthy immune function. A super-strong all-rounder.

SARDINES, MACKEREL, RAINBOW TROUT

Oily fish can be a cost-effective way of giving your diet a mega-healthy boost. Varieties like sardines and mackerel are among the best sources of omega 3 you'll find, and there's substantial scientific evidence that including them in your diet can play a significant role in reducing risk of cardiovascular disease, as well as dementia. In 2013, researchers at Harvard School of Public Health and the University of Washington published findings indicating that older people with omega 3-rich diets were 25% less likely to die prematurely and a third less likely to die of heart disease. They're also a good source of vitamin D, essential for helping the body absorb calcium, to keep bones and teeth healthy - and something many Brits are lacking, particularly during winter with the lack of sunlight, possibly resulting in low mood, depression and fatigue.

COD, PLAICE, HADDOCK

White fish doesn't quite measure up to oily fish in the nutrition stakes, though it does still contain some omega 3, and can be a good source of selenium, B vitamins - which play a key role in a range of vital functions, including energy production, cell metabolism, immune function and skin health - plus iodine, important for thyroid function. Perhaps the best thing about white fish, though, is that it's a very good example of a lean, low-fat source of protein, so including them in your diet can help avoid weight gain and the health risks associated with consuming too much red meat, like an increased risk of heart disease, stroke and cancer.

OYSTERS

They tend to be a 'love them or hate them' food, but oysters - as well as being famed for their aphrodisiacal properties - have another super-power up their slippery sleeve: they're one of the best sources of zinc. This important mineral plays a range of roles, as more than 300 different enzymes rely on zinc to function properly, including energy and cell metabolism, skin and eye health, and organ, immune and digestive function. It's also believed that zinc deficiency can impact how our brain and body responds to stress.

PRAWNS

Low in fat and calories, but high in protein, prawns are a great dietary addition for maintaining a healthy weight. It's also worth mentioning their calcium and potassium contents - helpful for bones, teeth and brain, heart and nerve function - plus vitamins A and E, which play a role in keeping eyes and skin healthy and supporting immune function.

MUSSELS

These tasty little morsels are another protein, selenium, iron and omega 3 source. They're also one of the top natural sources of vitamin B12. It's believed that a significant amount of us could be lacking in this complex vitamin, possibly resulting in fatigue, anaemia and low mood and depression, while for some people, a major deficiency (which isn't always just linked to diet but could, for example, be due to an autoimmune condition called pernicious anaemia) could lead to serious long-term complications, affecting heart health, fertility and nervous system function.

HOW MUCH SHOULD I BE EATING?

There's no doubt fish and seafood play an important role in a balanced, healthy diet, but there are two other points to consider. Firstly, look out for proof that your fish and seafood has been sourced responsibly and sustainably (this should be indicated on supermarket packaging, or have a chat with your fishmonger). Secondly, there are some negative health risks associated with consuming too much oily fish, as, over time, this may result in a build-up of pollutants, including mercury. Official guidelines advise eating at least one or two portions of oily fish a week but no more than four (or no more than two for women who are pregnant, breastfeeding or hoping to get pregnant in the near future). To find out more, visit www.nhs.uk/Livewell/Goodfood/Pages/fish-shellfish.aspx