Eating one portion of seafood on a weekly basis may cut your heart attack risk by 50 percent, according to experts.

Shrimp, crabs, squid, and scallops have just as much vitamins and minerals as fish like salmon or cod and they also contain omega-3, an essential fatty acid that promotes heart health, the Daily Mail reported.

Experts say that unlike cheese, red meat and fast foods, which contain cholesterol and are high in saturated fats, seafood does not increase levels of bad cholesterol in the body; therefore seafood is unlikely to have a major impact on cholesterol levels.

Jackie Lynch of the website well-well-well.co.uk told the Mail that people should try to eat fresh seafood because frozen products contain more sodium, which many already consume more than twice the daily recommended amount.

Lynch said that best thing about eating crab is that it contains high levels of protein and omega-3 and has trace elements of selenium, chromium, calcium, copper, zinc, minerals and antioxidants that are helpful in reducing blood pressure.

However Lynch warned that crab should only be an occasional treat for those with high cholesterol, because most shellfish, especially crustaceans, are high in cholesterol.

Experts say that squid has high levels of protein as well as omega-3, copper, zinc, B vitamins and iodine. Foods that contain copper are good for the body's absorption, storage and metabolism of iron and the formation of red blood cells.

Oysters are high in protein. zinc, Omega-3 and are low in cholesterol. Nutrition experts also say that they contain large amounts of the amino acid tyrosine, which helps boost mood and regulate stress levels.  Oysters also contain more zinc than most other foods, which supports reproductive and sexual health, especially in men.

Mussels contain selenium, iron, folic acid, Vitamin A, B vitamins, zinc and iodine, the chemical element which helps an underactive thyroid produce tyrosine, the hormone which makes it effective.  Mussels also have the highest level of Omega-3 compared to all other shellfish and also contain high levels of folic acid and vitamin B12, nutrients that help with tiredness, confusion and nerve damage.

Scallops contain virtually no saturated fat and are low in calories.  Like all shellfish, these mollusks contain high levels of protein and omega-3 and are a good source of vitamin B, magnesium and potassium. 

Prawns and shrimp are high in levels of vitamin B12, which is necessary for cell division and selenium, which has highly protective properties and supports the immune system function and thyroid function. 

Lobsters are high in iodine, selenium, and B vitamins and contain less cholesterol and calories than lean beef, pork, and shrimp.  While lobster's often seen as a luxury food, it is a good source of lean protein, and its high levels of vitamin E protect the body's cells from damage.

Clams are also a great source of protein and are extremely high in zinc, which is good for skin and hair health as well as for immune function. Clams also contain high amounts of Vitamin A in the form of retinol, which helps boost night vision.