In recent years, a decline in the incidence of cardiovascular disease (CVD) and coronary heart disease (CHD) has been seen both among some European countries and also in the United States.
In a new systematic and meta-analysis, Victoria Burley, Associate Professor in Nutritional Epidemiology and Deputy Postgraduate Research Tutor Nutrition and Public Health, senior lecturer, University of Leeds and colleagues examined dietary fiber intake and any potential dose-response association with coronary heart disease and cardiovascular disease.
For the study researchers searched electronic databases reporting associations between fiber intake and coronary heart disease or cardiovascular disease, with a minimum follow-up of three years and published in English between 1 January 1990 and 6 August 2013.
The team identified 26 publications in total: 14 from the main search plus 12 from the update. The cohorts were mainly from the United States, two Japanese and one from Australia.
The researchers examined the following fiber intake; total, insoluble (whole grains, potato skins etc), soluble (legumes, nuts, oats, barley etc.), cereal, fruit, vegetable and others (that is, derived from non-cereal, vegetable, or fruit sources).
The results revealed a significantly lower risk of 9% was seen for both CVD and CHD with every additional 7 g/day of total fiber consumed. An additional 7 grams of fiber can be provided through eating just one portion of whole grains plus a portion of beans or lentils, or through two to four servings of fruit and vegetables
Results from total fiber intake, insoluble, fruit and vegetable showed that event risk fell steadily with increasing total fiber intake.
Insoluble fiber and fiber from cereal and vegetable sources were inversely associated with risk of coronary heart disease and cardiovascular disease.
A lower risk of CHD or CVD is associated with higher fruit fiber intakes of up to around 5-8 g/day, which is equivalent to about two to four servings of fruit.
A significantly lower risk of 9% was seen for both CVD and CHD with every additional 7 g/day of total fiber consumed. Findings were aligned with current recommendations to increase fiber intake and showed a large risk reduction with an achievable increase in daily fiber intake.
In their conclusion the team writes “Greater dietary fiber intake is associated with a lower risk of both cardiovascular disease and coronary heart disease. Findings are aligned with general recommendations to increase fiber intake. The differing strengths of association by fiber type or source highlight the need for a better understanding of the mode of action of fiber components.”
The researchers note their findings relate only to fiber from food intake rather than from fiber isolates or extracts.
This paper appears in BMJ, the British Medical Journal.