Background Cardiovascular disease (CVD) is a major cause of mortality and morbidity in developed countries. CVD risk can be modified via lifestyle habits and some prospective studies indicate greater fibre intake is associated with lower CVD risk. The aim of this work was to explore this association using data from the UK Women’s Cohort Study.

Methods 27,731 middle-aged women, with no prior history of CVD, were recruited in the mid 1990’s and followed for a median of 14.7 years. Habitual dietary intake was assessed with a food-frequency questionnaire at study baseline, along with other health and lifestyle information. Risk of incident coronary heart disease (CHD), stroke and CVD were assessed in relation to intakes of total dietary fibre, soluble fibre, insoluble fibre and fibre from key food sources. Cox proportional hazard regression was used to explore risk using both categorical (fifths of intake) and continuous exposure variables adjusting for age, body mass index, energy intake, ethanol, physical activity, smoking and socio-economic status.

Results After 14.7 years, 513 CHD, 406 stroke and 902 CVD cases were observed. After adjustment, a number of inverse associations were observed with increasing intakes of dietary fibre, specifically for total fibre intake with stroke and CVD. Risk was reduced in each intake quintile which was compared to the lowest. CVD risk was also significantly reduced with greater insoluble fibre intake, in each intake quintile compared to lowest; HR 0.71 (95% CI 0.54, 0.95), p= 0.019 for highest vs. lowest consumers.

Stroke risk was significantly reduced with greater cereal fibre intake in a continuous model, for each 3g/day increase; HR 0.93 (0.86, 1.00), p=0.048. Stroke and total CVD risk reduction were also associated with greater fibre from nuts/seeds in each intake category vs. lowest consumers and CHD risk was reduced in highest vs. lowest consumers of fibre from nuts/seeds; HR 0.71 (0.51, 1.00), p=0.048.

Conclusion Fibre intakes in the UK and many other countries fall below recommendations. Results indicate greater intakes, especially of cereal fibre, may be protective against risk of incident CVD. Although fibre intakes from different sources correlate, the contrasting observations for different exposures indicate associations are food-specific rather than simply result from residual confounding of lifestyle characteristics. However, associations may be explained by other non-fibre components within foods. Promoting intake of particularly beneficial food sources of fibre may prevent CVD development.