High-fibre diet after heart attack may improve survival, study finds

People who survive a heart attack may be able to improve their longevity by increasing their dietary intake of fibre, particularly cereal fibre, suggests research published in the British Medical Journal (online, 29 April 2014).

Analysis of longitudinal data from two large US cohorts found that myocardial infarction (MI) survivors who subsequently ate the highest amount of dietary fibre had a 25 per cent lower risk of all-cause mortality than those with the lowest fibre intake. Increasing fibre intake from before to after MI was also beneficial, leading to reductions in both all-cause and cardiovascular mortality.

Noting that dietary fibre is known to reduce the risks of hypertension, obesity and diabetes, the researchers write: “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.”

Lead author Shanshan Li, from Harvard School of Public Health, Boston, Massachusetts, and team identified 2,258 women from the Nurses’ Health Study and 1,840 men from the Health Professionals Follow-Up Study who suffered a non-fatal MI during a mean of 8.7 and 9.0 years of follow-up, respectively. All participants completed food-frequency questionnaires before and after their MI.

When participants were stratified into fifths of total fibre intake, the pooled multivariate-adjusted hazard ratio (HR) for all-cause mortality was 0.75 (CI 0.58–0.97, P=0.03) for those in the highest versus the lowest fifth.

When the three types of dietary fibre were analysed separately, the protective effect was significant for cereal fibre, with HRs of 0.73 (0.58–0.91) for all-cause mortality and 0.72 (0.52–0.99) for cardiovascular mortality, but not for fruit or vegetable fibre.

Additionally, the degree to which people increased their fibre intake post-MI as opposed to pre-MI was inversely associated with subsequent all-cause and cardiovascular mortality, with pooled adjusted HRs of 0.69 (0.55–0.87) and 0.65 (0.47–0.90), respectively.