Dietary fibre and cardiovascular disease mortality in the UK Women’s Cohort Study

Abstract

Objectives and Background: Dietary fibre has been associated with improvements in key risk factors for cardiovascular disease (CVD). Prior research has focussed more on CVD development in men andour aim was therefore to explore the association between dietary fibre intake and CVD mortality using data from the United Kingdom Women's Cohort Study (UKWCS).Methods and results: Dietary fibre intake from 31,036 women was calculated both as non-starch polysaccharide (NSP) and using the Association of Official Analytical Chemist (AOAC) method from food-frequency questionnaires. Participants were free from history of CVD at baseline and mean age at recruitment was 51.8 years (standard deviation 9.2). Mortality records for participants were linked from national registry data and 258 fatal CVD cases (130 stroke, 128 coronary heart disease (CHD)) were observed over an average follow-up period of 14.3 years.Total dietary fibre (NSP/AOAC) or fibre from different food sources were not associated with reduced fatal CHD, stroke or CVD risk in the full sample. For every 6g/day increase in NSP, the hazard ratio (HR) was 0.91 (95%Confidence Interval (CI) 0.76 to 1.08) or for every 11g/day increase in fibre assessed as AOAC, the HR was 0.92 (95% CI 0.80 to 1.05). Sensitivity analyses suggest a possible protective association for cereal sources of fibre on fatal stroke risk in overweight women, 0.80 (95%CI 0.65 to 0.93) p<0.01 and for fibre density and fatal stroke in women free of hypertension or angina 0.83 (95% CI 0.70 to 0.99) p=0.04Conclusions: In the UKWCS, a sample of health-conscious women, greater dietary fibre intake may confer no additional cardiovascular benefit, in terms of mortality, but may contribute to lower fatal stroke risk in those free of cardiovascular risk factors (hypertension/angina) or overweight women who consume greater cereal fibre.

Cereal fibre intake and risk of mortality from all causes, CVD, cancer and inflammatory diseases: a systematic review and meta-analysis of prospective cohort studies

“…After scrutinising the full-text papers and based on our inclusion criteria, eighteen prospective studies were selected for the systematic review. However, we included only fourteen studies (3)(4)(5)9,10,(12)(13)(14)15,(19)(20)(21)(22)(23) in the meta-analysis, and the other four studies were excluded from the meta-analysis because of the following reasons. Two studies conducted by Rimm et al (24) and Wolk et al (25) were not included because they had reported RR or HR for all CVD events simultaneously and had not separated the findings for fatal and non-fatal outcomes.…”

“…The characteristics of the studies included in the systematic review are presented in Table 1. Out of eighteen cohort studies published between 1996 and 2015, ten were conducted in the USA (3)(4)(5)8,10,12,21,(23)(24)(25) , two in the UK (14,19) , two in Australia (15,26) and the rest in Japan (20) , Finland (22) and Netherlands (13) , and one pooled analysis based on cohorts in the USA and UK (9) . The total number of participants in these studies ranged from 1373 (13) to 388 122 (8) , with age ranging from 30 to 99 years.…”

“…From eighteen studies included in the systematic review, one study was conducted exclusively in patients with myocardial infarction (MI) (12) , and two studies were conducted in patients with type 2 diabetes and breast cancer, respectively (3,21) . From eighteen citations, six papers had reported RR for all-cause mortality (3,8,10,12,13,23) , seventeen publications for CVD mortality (3)(4)(5)(8)(9)(10)(12)(13)(14)(15)19,20,22,(23)(24)(25)(26) , four studies for cancer mortality (8,10,21,23) and three papers for inflammation-related mortality (8,10,15) . In some publications, cereal fibre was defined as fibre or NSP from flour, rice, pasta, References identified from PubMed, Scopus, EMBASE, ISI web of science and Google Scholar (n 9895)…”

“…Dietary patterns or scores (n 12) Mortality not an outcome (n 109) Cereal fibre intake not an exposure (n 30) pastry, bread, dark bread and breakfast cereals (3,5,10,13,14,15,19,20) . However, others did not precisely report how they defined cereal fibre (4,8,9,12,21,22,(23)(24)(25)(26) .…”

Dietary fibre intake and risk of ischaemic and haemorrhagic stroke in the UK Women’s Cohort Study

“…Total fibre intake was estimated 63 both as non-starch polysaccharide (NSP) and using the Association of Official Analytical Chemist 64 methods (AOAC) as detailed in a previous study (17). Additionally, soluble fibre, insoluble fibre and 65 fibre from key food sources was estimated as in this previous study.…”