Dietary Fiber Intake and Risk of Cardiovascular Disease
Dietary Fiber Intake and Risk of Cardiovascular Disease
Objective To investigate dietary fibre intake and any potential dose-response association with coronary heart disease and cardiovascular disease.
Design Systematic review of available literature and dose-response meta-analysis of cohort studies using random effects models.
Data sources The Cochrane Library, Medline, Medline in-process, Embase, CAB Abstracts, ISI Web of Science, BIOSIS, and hand searching.
Eligibility criteria for studies Prospective studies reporting associations between fibre 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.
Results 22 cohort study publications met inclusion criteria and reported total dietary fibre intake, fibre subtypes, or fibre from food sources and primary events of cardiovascular disease or coronary heart disease. Total dietary fibre intake was inversely associated with risk of cardiovascular disease (risk ratio 0.91 per 7 g/day (95% confidence intervals 0.88 to 0.94)) and coronary heart disease (0.91 (0.87 to 0.94)). There was evidence of some heterogeneity between pooled studies for cardiovascular disease (I=45% (0% to 74%)) and coronary heart disease (I=33% (0% to 66%)). Insoluble fibre and fibre from cereal and vegetable sources were inversely associated with risk of coronary heart disease and cardiovascular disease. Fruit fibre intake was inversely associated with risk of cardiovascular disease.
Conclusions Greater dietary fibre intake is associated with a lower risk of both cardiovascular disease and coronary heart disease. Findings are aligned with general recommendations to increase fibre intake. The differing strengths of association by fibre type or source highlight the need for a better understanding of the mode of action of fibre components.
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. Although rates of CVD have long since peaked for many developed countries and mortality from the disease is declining, it still accounts for almost half (48%) of all deaths in Europe and a third (32.8%) of all deaths in the US.
In the 1970s, the protective link was proposed between dietary fibre (in the form of whole grain foods) and ischaemic heart disease. Many observational and experimental studies have since examined the relation between dietary fibre or fibre rich foods and total cardiovascular risk or cardiovascular risk factors—such as hypertension, central obesity, insulin sensitivity, and elevated plasma cholesterol.
The protective effect of dietary fibre on risk of CVD and CHD is biologically plausible, and there are many potential mechanisms through which fibre may act on individual risk factors. Soluble, viscous fibre types can affect absorption from the small intestine because of the formation of gels that attenuate postprandial blood glucose and lipid rises. The formation of gels also slows gastric emptying, maintaining levels of satiety and contributing towards less weight gain. Soluble fibre and resistant starch molecules are additionally fermented by bacteria in the large intestine, producing short chain fatty acids, which help reduce circulating cholesterol levels.
In addition to fibre, many other potentially beneficial compounds within high fibre foods could have protective effects. For example, compounds in grains such as antioxidants, hormonally active lignans, phytosterols, amylase inhibitors, and saponins have all been shown to influence risk factors for CHD, and the combination of compounds within grains could be responsible for their protective effect.
The aim of this work was to review literature published since 1990, in generally healthy populations, concerning dietary fibre intake and cardiovascular risk, and to update reports published in the United Kingdom by the Committee on Medical Aspects of Food Policy, in the early 1990s.
Abstract and Introduction
Abstract
Objective To investigate dietary fibre intake and any potential dose-response association with coronary heart disease and cardiovascular disease.
Design Systematic review of available literature and dose-response meta-analysis of cohort studies using random effects models.
Data sources The Cochrane Library, Medline, Medline in-process, Embase, CAB Abstracts, ISI Web of Science, BIOSIS, and hand searching.
Eligibility criteria for studies Prospective studies reporting associations between fibre 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.
Results 22 cohort study publications met inclusion criteria and reported total dietary fibre intake, fibre subtypes, or fibre from food sources and primary events of cardiovascular disease or coronary heart disease. Total dietary fibre intake was inversely associated with risk of cardiovascular disease (risk ratio 0.91 per 7 g/day (95% confidence intervals 0.88 to 0.94)) and coronary heart disease (0.91 (0.87 to 0.94)). There was evidence of some heterogeneity between pooled studies for cardiovascular disease (I=45% (0% to 74%)) and coronary heart disease (I=33% (0% to 66%)). Insoluble fibre and fibre from cereal and vegetable sources were inversely associated with risk of coronary heart disease and cardiovascular disease. Fruit fibre intake was inversely associated with risk of cardiovascular disease.
Conclusions Greater dietary fibre intake is associated with a lower risk of both cardiovascular disease and coronary heart disease. Findings are aligned with general recommendations to increase fibre intake. The differing strengths of association by fibre type or source highlight the need for a better understanding of the mode of action of fibre components.
Introduction
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. Although rates of CVD have long since peaked for many developed countries and mortality from the disease is declining, it still accounts for almost half (48%) of all deaths in Europe and a third (32.8%) of all deaths in the US.
In the 1970s, the protective link was proposed between dietary fibre (in the form of whole grain foods) and ischaemic heart disease. Many observational and experimental studies have since examined the relation between dietary fibre or fibre rich foods and total cardiovascular risk or cardiovascular risk factors—such as hypertension, central obesity, insulin sensitivity, and elevated plasma cholesterol.
The protective effect of dietary fibre on risk of CVD and CHD is biologically plausible, and there are many potential mechanisms through which fibre may act on individual risk factors. Soluble, viscous fibre types can affect absorption from the small intestine because of the formation of gels that attenuate postprandial blood glucose and lipid rises. The formation of gels also slows gastric emptying, maintaining levels of satiety and contributing towards less weight gain. Soluble fibre and resistant starch molecules are additionally fermented by bacteria in the large intestine, producing short chain fatty acids, which help reduce circulating cholesterol levels.
In addition to fibre, many other potentially beneficial compounds within high fibre foods could have protective effects. For example, compounds in grains such as antioxidants, hormonally active lignans, phytosterols, amylase inhibitors, and saponins have all been shown to influence risk factors for CHD, and the combination of compounds within grains could be responsible for their protective effect.
The aim of this work was to review literature published since 1990, in generally healthy populations, concerning dietary fibre intake and cardiovascular risk, and to update reports published in the United Kingdom by the Committee on Medical Aspects of Food Policy, in the early 1990s.