BMJ study, people who ate the most fibre had a 25% lower chance of dying within nine years after an MI compared with those who ate the least.
Researchers said that with more people surviving an MI, it was increasingly important to consider which lifestyle changes can help patients live longer.
A team from the Harvard School of Public Health in Boston, Massachusetts, looked at data from 173,229 patients, who completed lifestyle questionnaires every two years.
Over nine years, researchers followed 4,098 patients who survived an MI, during which time 1,133 (28%) died.
Fibre lowers cardiovascular risks
Only cereal fibre – not from fruit or vegetables – was strongly linked to increased survival. Each 10g per day increase in dietary fibre lowered the risk of dying by 15%.
Researchers believe a high-fibre diet may lower coronary heart disease risk by reducing systemic inflammation, cholesterol levels and cell damage from free radicals.
The diet may also improve insulin sensitivity and overall glycaemic control, and benefit gut microbiota.
Study authors said: ‘Future research on lifestyle changes post-MI should focus on a combination of lifestyle changes and how they may further reduce mortality rates beyond what is achievable by medical management alone.’
Adults are recommended to eat at least 18g of fibre daily but most people eat an average of just 14g.
Dr G Mohan.