Omega-3 fats are a star heart health nutrient, but fish contain other valuable nutrients: potassium and vitamins B6 and B12. A review of studies found that eating four or more portions of fish a week was associated with a 21 per cent reduced risk of having a heart attack.
One study found that eating 300g (10oz) of fish a week protected against abnormal heart rhythms by improving the electrical properties of the heart cells.