Effect of fibre intake on cardiovascular health

Cardiovascular disease & coronary heart disease

• '…there is epidemiological evidence for a protective effect of dietary fibre intake >24g per day on cardiovascular disease risk'.

• 'NSP fibre probably reduces CVD risk'.
• 'While fruits and legumes rich in viscous (soluble) forms of NSP and dietary fibre are associated with reduced LDL cholesterol, insoluble forms derived from wholegrain cereals also appear to confer cardioprotection possibly in association with other constituents of wholegrain'.
• 'There is no convincing evidence that fibre supplements and manufactured and functional foods containing them reduce cardiovascular risk'.

• 'Prospective cohort studies indicate that a diet rich in dietary fibre is associated with a lower incidence of cardiovascular diseases, coronary events […]. Over the ranges of intakes studied, it was found that as more dietary fibre was consumed a greater reduction in risk was observed'. 'Higher cereal fibre consumption is associated with a lower incidence of coronary events[…], although the evidence is more limited for individual types of dietary fibre due to the smaller number of studies'.
• 'Randomised controlled trials indicate no effect of (total, mixed) dietary fibre intake on cardiovascular […] risk factors considered in this report'.

• Dietary fibre from various foods probably protects against the development of CVD.

• 'the evidence regarding the primary prevention of CHD by an increased dietary fibre intake is judged as probable'.
• 'The results regarding the intake of dietary fibre from cereal products and fruit show with possible evidence that there is an inverse association with the risk of CHD; whereas regarding the intake of dietary fibre intake from vegetables, there is possible evidence that there is no association with the risk of CHD'.
• 'possible evidence that an increased intake of both soluble and insoluble dietary fibre is associated with a reduced CHD risk, although soluble dietary fibre seems to have a greater effect than insoluble dietary fibre'.

• 'A high-fibre diet protects against coronary heart disease. The lowest risks are found at the highest levels of fibre intake (between 3.1 and 3.5 grams of dietary fibre per megajoule)'.
• 'There is evidence that fibres from whole-grain products and fruit are particularly effective at protecting against coronary heart disease'.

Blood pressure

• 'Small, but rather consistent, effects on blood pressure have been observed for diets rich in fibre from e.g. cereals, fruit and vegetables, although the contribution of dietary fibre per se to this effect remains to be established'.

• NSP (fibre) is 'protective against coronary heart disease and has also been used in diets to lower blood pressure'.

• 'Randomised controlled trials also indicate that higher intake of oat bran and isolated β-glucans […] lower blood pressure'.

• 'Dietary fibre, mainly in the form of viscous fibre, can modulate blood pres­sure'.

• 'there is probable evidence that increased dietary fibre consumption in a population with different blood pressure levels lowers the risk of hypertension. This also applies to the food group of whole-grain products'.

• 'The total intake of dietary fibre has a modest effect on blood pressure. It is unclear whether the type of fibre also plays a role in the effect on blood pressure'.

Blood lipids

• 'Viscous types of dietary fibre may contribute to reducing total and LDL-cholesterol concentration. The effects are limited at amounts usually consumed from foods'.

• 'Randomised controlled trials also indicate that higher intake of oat bran and isolated β-glucans leads to lower total cholesterol, LDL cholesterol and triacylglycerol concentrations'.

• 'Viscous types of soluble fibre lower plasma levels of total cholesterol and LDL-cholesterol'.

• 'There is probable evidence that dietary fibre in total does not influence the plasma HDL cholesterol concentration'.
• 'there is convincing evidence that increasing the intake of soluble dietary fibre in total slightly lowers the plasma concentration of HDL cholesterol'.
• 'there is probable evidence that psyllium and guar lower the plasma concentration of HDL cholesterol and probable evidence that, in contrast, oatmeal and pectin do not'.
• 'There is convincing evidence that there is no influence of dietary fibre in total on the plasma triglyceride concentration'.
• 'There is convincing evidence that increasing the intake of soluble dietary fibre in total does not influence the plasma concentration of triglycerides. This also applies to special investigations with oatmeal, psyllium, pectin and guar'.
• 'There is convincing evidence that β-glucan from barley reduces the plasma concentration of triglycerides'.
• 'There is convincing evidence that β-glucan from barley lowers the plasma concentrations of total and LDL cholesterol'.
• 'With convincing evidence, β-glucan from barley does not reduce the plasma concentration of HDL cholesterol'.

• '…increasing intakes of foods rich in dietary fibre are associated with reduced risk of impaired glucose control. Dietary fibre intakes associated with favourable effects are >2.6 g per MJ and about 30 g per day, although the contribution of dietary fibre per se to this effect remains to be established.'
• 'Dietary fibre intakes reported to be associated with a reduced risk for type 2 diabetes are >2.6 g per MJ or about 25 to 30 g per day, although the contribution of dietary fibre per se to this effect remains to be established.'

• Probable evidence that NSP fibre decreases the risk of developing type 2 diabetes

• 'Prospective cohort studies indicate that a diet rich in dietary fibre is associated with a lower incidence […] type 2 diabetes mellitus […]. Over the ranges of intakes studied, it was found that as more dietary fibre was consumed a greater reduction in risk was observed'. 'Higher cereal fibre consumption is associated with a lower incidence of […] type 2 diabetes mellitus […], although the evidence is more limited for individual types of dietary fibre due to the smaller number of studies'.
• 'Randomised controlled trials indicate no effect of (total, mixed) dietary fibre intake on […] type 2 diabetes mellitus risk factors considered in this report'.

• 'There is probable evidence that dietary fibre intake is in­versely associated with type-2 diabetes. 'This might partly be mediated by wholegrain intake'.

• 'Due to the varying results, the evidence regarding lack of an association between total intake of dietary fibre and the risk of diabetes is judged as possible'.
• 'The evidence regarding a reduced risk of diabetes due to higher intake of insoluble dietary fibre is judged as insufficient'.
• 'There is possible evidence that there is no association between water-soluble dietary fibre and the risk of diabetes.'
• 'prospective cohort studies indicate with high consistency that high intake of whole-grain products or dietary fibre from cereal products, respectively, causes a lower risk of diabetes. The evidence regarding this association is judged as probable'.
• 'The evidence regarding a lack of association between the intake of dietary fibre from fruit and vegetables and the risk of diabetes is judged as probable'.

• 'Although it has not been convincingly demonstrated that total fibre intake protects against the development of type-2 diabetes mellitus, there are fairly strong indications that whole-grain products exert a protective effect'.

• 'In conclusion, dietary fibre is the most important dietary factor for faecal bulk and regular bowel movements and may reduce colon cancer risk'.
• 'Previous estimates of fibre intakes in adults necessary to achieve minimal risk of intestinal disorders, particularly colon cancer, range from 26 to 45 g per day. One meta-analysis of prospective cohort studies found a 10% decrease in the risk of colorectal cancer for each 10 g per day increase of dietary fibre intake. However, a consistent relation has not been shown in all cohort studies'.

• 'There is a moderately large amount of data on the possible association between dietary fibre and the risk for colorectal cancer; the results of studies have varied and no firm conclusion can be drawn, but the available data suggest that high intakes of dietary fibre possibly reduce the risk for colorectal cancer'.

• 'Foods containing dietary fibre probably protect against colorectal cancer; there is limited evidence that such foods protect against oesophageal cancer'.
• 'Foods rich in dietary fibre may also have a protective effect indirectly because they are relatively low in energy density and thus impact risk of colorectal and oesophagus cancer via a reduction of body fatness'.

• 'Prospective cohort studies indicate that a diet rich in dietary fibre is associated with a lower incidence of […] colo-rectal cancer. Over the ranges of intakes studied, it was found that as more dietary fibre was consumed a greater reduction in risk was observed'.
• 'Higher cereal fibre consumption is associated with a lower incidence of […] colo-rectal and colon cancer, although the evidence is more limited for individual types of dietary fibre due to the smaller number of studies'.

• 'There is convincing evidence for a protective effect of dietary fibre against colorectal cancer and limited-suggestive evidence for a protec­tive effect against breast cancer'.

• Insufficient evidence regarding an association between dietary fibre intake and oesophagus, endometrium, stomach and pancreas cancer development.
• 'There is possible evidence that there is no association between the intake of dietary fibre and the risk of cancer of the breast'.
• 'There is probable evidence that there is a risk-reducing association between the intake of dietary fibre from cereal products and the risk of colorectal cancer'.
• Possible evidence that high intake of dietary fibre from cereals lowers the risk of stomach cancer.
• Possible evidence of a risk-reducing association between total intake of dietary fibre and risk of colorectal cancer.

• 'In observational research, people with a very low fibre intake exhibited an increased risk of colon cancer. The differences between studies are nonetheless, too great to allow conclusions to be drawn regarding other levels of consumption'.
• 'There is insufficient evidence that total dietary fibre intake has a protective effect against colon cancer.'
• 'High consumption of fruit fibre may possibly be associated with a lower risk of colon cancer'.

•  '…increased intake of dietary fibre, both from naturally fibre-rich foods and added fibre or fibre supplements, has been shown to be related to improved weight maintenance in adults and sustained weight reduction in overweight subjects'.
• 'Estimated intakes associated with this effect in adults are in the order of>25 g dietary fibre per day (from wholegrain cereals, fruit and vegetables) and >3.1 g total fibre per MJ'.
• 'Results of intervention and observational studies in children indicate that a fibre intake corresponding to 2 to 3 g per MJ is compatible with normal growth and development'.

• There is convincing evidence that high dietary intake of non-starch polysaccharides (NSP) reduces the risk of weight gain and obesity.
• 'The currently available evidence does not support a major effect of fiber intake on weight loss, but evidence is consistent with modest long-term effects of higher consumption of fiber-rich foods on body weight gain'.

• 'The majority of the cohort studies indicate that increased dietary fibre intake is associated with a reduced risk of obesity. Therefore, the evidence regarding this association is judged as probable'.
• 'Regarding children and adolescents, the cohort studies available show with possible evidence that there is no association between dietary fibre intake and the risk of obesity. The relevance of dietary fibre intake in children and adolescents might depend on the initial body weight, but the respective evidence is insufficient'.

•  'No association was found between dietary fibre intake and body weight'.

• 'There is probable evidence that dietary fibre intake is associated with lower weight gain in adults'.

• 'The present studies indicate with possible evidence that there is no association between dietary fibre intake and the occurrence of the metabolic syndrome'.

• '…an intake of 25 g per day of dietary fibre from mixed foods (as AOAC fibre or equivalent) is compatible with an intestinal transit time of about two to three days and a defaecation frequency of 1 per day and a faecal moisture of >70% and may be considered adequate for normal laxation in adults'.
• 'Dietary fibre intake of 2 g per MJ should be adequate for normal laxation in children based on the dietary fibre intake that is considered adequate for normal laxation in adults (25 g, equivalent to 2 to 3 g per MJ for daily energy intakes of 8 to 12 MJ) and taking into account that energy intake relative to body size in children is higher than in adults'.

• 'NSP clearly affect bowel habit and so, to a lesser extent, does resistant starch'.

• 'Randomised controlled trials indicate that total dietary fibre, wheat fibre and other cereal fibres, as they are classified in this report, increase faecal mass and decrease intestinal transit times'.

• Insoluble fibre, particularly lignified types of fibre such as those in wheat bran, has a marked effect on faecal bulk.

• 'Dietary fibre increases the speed at which food passes through the gastrointestinal tract and can thus reduce the risk of constipation. The required level of fibre intake for optimal intestinal transit speed in adults is, in the case of a mixed diet, 32 to 45 grams per day. Furthermore, it is essential that people also have a sufficiently high fluid intake and take enough physical exercise'.

• Dietary fibre may (possibly) reduce the risk of dental caries

• 'There is a lack of evidence for oral health in relation to dietary fibre intake'.