Eating seafood twice a week can boost heart and brain function, improve overall health and lower the risk of developing some deadly diseases, scientists say.

Cardiovascular and Alzheimer’s disease risk could fall by 30 per cent, and dementia by 10 per cent with about 300 grams of seafood on the menu weekly, a study into its benefits has found.

Higher seafood consumption has also been linked to improved mental health outcomes, with adults eating regular weekly servings showing a lower risk of depression and anxiety.

“Two servings of fish a week can give you enormous benefits for every system in your body,” Curtin University epidemiologist Alexandra McManus said.

“We’re not talking about a huge amount, and we’re not talking about anything really expensive, either.

“It’s all about being healthy throughout our lifespan.”

For older adults, regularly eating seafood can help bone health and muscles. Photo: AAP

Researchers stipulate that at least one serving must be high in Omega-3s fatty acids, but they also recommend eating a “variety of seafood because it has so many health benefits”.

“Whilst there are a number of supplements on the market that are high in Omega-3s and can provide good health benefits, there are many more benefits to eating whole seafood,” McManus said.

“Seafood is a great source of lean protein and provides other nutrients, including vitamins A and D, B group vitamins, iodine, zinc, selenium and iron.”

For older adults, regularly eating seafood can help boost bone health and muscle strength.

“If you have, say, four servings of seafood a week, you can maintain that strength in your muscles and that overall function,” McManus said.

“Once you have good muscle strength and good muscle function, then you’ve got less chance of falling,” she added.

Omega-3s help reduce inflammation, allergies and asthma, and support blood vessel function and maintain brain structure.

There are also benefits for common conditions that are now becoming endemic, like diabetes, behavioural and mental health issues and cancer, McManus said.

During pregnancy, eating seafood can help reduce preterm birth and low birth weights, and improve a mother’s overall health.

Omega-3s are also critical for foetal and baby brain development.

There is also emerging evidence that high doses of Omega-3s can also benefit critically ill hospital patients by protecting them from infection, reducing the time spent in care, McManus said.

The research – the largest independent review of seafood and human health conducted in the past decade, analysing more than 250 scientific studies – has helped scientists broaden their understanding of how much seafood people should eat and what types.

“Previously, it was just eat more fish, but this is eat more seafood as part of a healthy diet,” McManus said.

-AAP