Increasing fish oil intake--any net benefits?

For over a decade, there have been suggestions that a diet high in fish oils might protect against coronary heart disease. In the UK, fish oil supplements are often taken for cardiovascular or inflammatory diseases. In addition, 2 years ago the Department of Health advised people to eat a portion of fish at least weekly to reduce the risk of heart disease. We examine whether extra fish in the diet or fish oil supplements rich in omega-3 fatty acids really improve health.