What are the cardiovascular benefits of including dietary fibres in a healthy diet?

A high intake of dietary soluble and insoluble fibre has been associated with a lower prevalence of major CVD risk factors such as dyslipidaemia, hypertension, diabetes and obesity1.

To ensure all the health benefits of dietary fibres, a daily intake of 25-45 g is recommended4,5.

A specific and significant cholesterol-lowering effect has been found especially with soluble fibres 1,2.

Furthermore, combining soluble fibres (10 g/day) with plant sterols, soy protein and nuts (almonds) into the diet (PORTFOLIO diet) has shown to potentially lower LDL-cholesterol up to 30% 6.

Regarding beta-glucan, several clinical studies have shown that a diet containing at least 3 g/day of oat/barley beta-glucan lowers TC and LDL-cholesterol by about 5-6% 3,7. It should be noted that beta-glucan consumption needs to be maintained for a sustained cholesterol-lowering effect.

See Table 11 to learn more on how to get the recommended amount of soluble fibres and beta-glucan through foods.

Daily beta-glucan consumption (≥3 g/day) may be recommended for hypercholesterolaemic patients for LDL-cholesterol reduction3,7.

Table 11 How to get the recommended soluble fibre and beta-glucan intake to help in lowering LDL-cholesterol.

Food Source Soluble fibre approximate amount in g Food Source Soluble fibre approximate amount in g
Legumes, 100 g, dry   Vegetables, 100 g, cooked  
Beans (black beans,
2-3
Broccoli
1
Lentils (yellow, green, orange)
1
Brussels Sprouts
3
Peas (chickpeas)
1
Carrots
1
Fruits, a medium piece   Grains, 50 g, cooked  
Apples
1
Barley
1
Bananas
1
Oatmeal
1
Blackberries (75 g)
1
Oat bran
1
Citrus Fruit (orange, grapefruit)
2
   
Pears
2
   
 
To include 5 g/day of soluble fibre, into the daily diet:
Example 1: 1 serving of oatmeal or oat bran/barley + 2 servings of fruit + 2 servings of vegetables
Example 2: 1 serving of oatmeal or oat bran/barley + 2 servings of fruit + 1 serving of legumes + 1 serving of vegetables
 
To include 3 g/day of beta-glucan into the daily diet:
2 servings (40-50 g) of oatmeal or oat bran or
1 serving (70-80 g) of barley
 

Adapted from: Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III), 20028

A diet that provides 25-45 g/day of total dietary fibres, including 5-15 g/day of soluble fibres, is effective, and recommended for blood cholesterol control4,5,9. Including 1-2 servings of oat or barley grains into the daily diet may have a particular benefit in lowering LDL-cholesterol (see above).

See Table 12 to learn more about how to reach the recommended daily amount of dietary fibres through foods.

Table 12 How to reach the dietary fibre recommendations.

Food group Approximate portion Approximate amount of total fibre per portion Suggested portions per day
Legumes
(e.g. chickpeas, dried beans, lentils, green peas)
30 g (dried)
4 g
0-1
Cereals
(e.g. brown rice, pearled barley, couscous, millet, whole oat, whole wheat bread , oatmeal, oat bran, rye bread)
80 g
 
8 g
2-4
Vegetables
(e.g. artichokes, broccoli, cabbage, carrots, cauliflower, eggplant, okra)
200 g
8 g
2 or more
Fresh fruit
(e.g. kiwi, apple, apricot, banana, cherries, nectarine, orange, peach, pear, plum)
150 g
4 g
1-2
Berries
(e.g. raspberries, blueberries, red- and blackcurrants)
50 g
3 g
1
Dried fruit
(e.g. dried prunes, dried apricot)
100 g
7 g
0-1
Nuts
(e.g. almonds, cashews, hazelnuts, pistachios, pecans, walnuts)
30 g
3 g
1

ADVICE: Choose appropriate quantities (portions) of foods from the different groups, alternating in the various meals of the day and during the week. Look at food labels to know the amount of dietary fibres in the food.

DIETARY FIBRES - MODE OF ACTION:

The exact mechanism through which soluble fibre lower LDL-cholesterol levels is not known. It is likely that the viscous bolus formed by the fibres in the gut lumen reduces the absorption of cholesterol and the reabsorption of bile acids. As a consequence, faecal excretion of cholesterol and of bile acids is increased, leading to an increased bile acid synthesis in the liver from cholesterol2.

It is probable that, in addition to fibre, foods that are high in dietary fibre contain other compounds (e.g. plant sterols/stanols, minerals, omega-3 and omega-6 PUFAs and specific phenolic compounds) that contribute to the protective cardiovascular effect of dietary fibres10.