Adapted from BMJ 27 Feb 2021
After a heart attack, the risk of sudden death is influenced by your past levels of physical activity.
People who performed moderate levels of leisure time exercise reduced their risk by 33% and those who performed high levels of exercise reduced the risk by 45%.
This study combined data from ten European longitudinal studies and found 30,000 people who had a heart attack. Around 5,000 people (18%) died within 28 days. Of these, 3,000 (62%) died instantly.
European Journal of Preventative Cardiology
Fish oil supplements however had no worthwhile cardioprotective effects according to a Cochrane Systemic Review done several years ago. A study looking at secondary prevention in 70-80 year olds, recently found similar effects. There was no difference between the omega 3 fish oil supplemented group and placebo over two years.
Cochrane Database Systemic Review and Circulation
Diabetes Diet 