Soluble Fibre and Diabetes

Soluble fibre can help to slow rises in blood sugar
Soluble fibre can help to slow rises in blood sugar

Soluble fibre is a form of water soluble carbohydrate that can’t be digested by the body.

Soluble fibre dissolves in water which can have beneficial effects on digestion, metabolism and longer term health.

Soluble fibres in our diet include pectin, psyllium, beta-glucans and gums such as guar gum.

Which foods contain soluble fibre?

Good sources of soluble fibre include:

  • Oats
  • Fruits and berries, particularly apples, strawberries and blueberries
  • Nuts and seeds
  • Beans, pulses and lentils
  • Vegetables

Health benefits

When soluble fibre interacts with water it forms a gel. In this gel form, the emptying of the stomach, the passage of digestion and the absorption of glucose are slowed.

Soluble fibre and blood glucose levels

Research studies have found that even modest increases in soluble fibre intake helps to lower blood glucose levels.

The fact that soluble fibre could help improve blood glucose in two ways.

The slowing down of passage through the digestive gives digestive hormones more time to act and by forming a gel with water, soluble fibre prevents carbohydrate from being so quickly absorbed by the small intestine.

Research published in the New England Journal of Medicine in 2000 compared a moderate fibre diet (24g of total fibre including 8g of soluble fibre) with a high fibre diet (50g of total fibre including 25g of soluble fibre) over 6 weeks.

The high fibre diet saw a reduction in pre-meal blood glucose levels by 0.7 mmol/l compared to the moderate fibre diet as well as reducing triglyceride levels and post meal blood glucose levels.

Soluble fibre and cholesterol

Soluble fibre also helps to reduce levels of LDL cholesterol, the so-called bad cholesterol. Research has found that soluble fibre in the diet results in bile being excreted from the body. Bile is produced from cholesterol and bile acids.

When more bile is excreted and therefore less bile is reabsorbed by the body, it can therefore help to regulate cholesterol as the body uses cholesterol from the blood to synthesise more bile.

Studies have that people with type 2 diabetes taking a 14g a day of psyllium for 6 weeks had reduced their LDL (bad) cholesterol by 9% and their total cholesterol by 7%.

Soluble fibre, appetite and weight loss

Soluble fibre has been shown to delay emptying of the stomach and slowing down the absorption of energy from foods. These digestion slowing effects also significantly delay the release of the appetite stimulating hormone ghrelin.

All of these effects help you to feel full and satisfied for longer which can help towards weight loss and weight management.

Soluble fibre and type 2 diabetes prevention

In addition to suppressing appetite and helping to lose weight, soluble fibre could help to decrease the likelihood of insulin resistance. Insulin resistance is when the body no longer responds effectively to its own insulin and if this is persistent, type 2 diabetes can develop.

Insulin resistance is known to develop in people that have higher than normal levels of fat around the abdominal organs such as the liver, pancreas and the gut. This form of fat is known as visceral fat and has different properties to subcutaneous fat, the fat under our skin.

A study published in 2011 and carried out by researchers at Wake Forest Baptist Medical Center, showed that higher intakes of soluble fibre resulted in decreased accumulation of in visceral fat.