Review · Nutrients · 2022Conflicts declared

Pectin and how it slows starch digestion

What it found

In people, animals and lab tests, pectin often slowed starch digestion and flattened the rise in blood sugar after a meal.

The size of the effect depended on the type of pectin and the food it was in.

What they found

Studies in people

Blood sugar in people

In people with diabetes, adding pectin and guar gum to food lowered the postprandial blood sugar rise overall. In insulin-dependent volunteers, the average rise from 45 to 180 minutes fell by more than 36%.

Insulin in people

In healthy volunteers, average blood sugar and serum insulin were both significantly lower from 15 minutes after eating pectin. Pectin plus guar gum in bread lowered both more than pectin alone.

Flattening, not just lowering

In nine volunteers who had gastric surgery and suffered hypoglycemia, pectin made blood sugar lower than controls at 15 and 30 minutes but higher at 90 and 120 minutes. This flattened the curve and avoided the dip.

Stomach emptying

A single pectin dose delayed stomach emptying in healthy and obese people. In 13 healthy adults, long-term pectin roughly doubled the stomach emptying half-time, and this returned to normal 3 weeks after stopping.

Not always a lower peak

Some studies found pectin delayed stomach emptying but made no significant difference to postprandial blood sugar. One study found a high-viscosity pectin increased stomach emptying, blood sugar rise and insulin.

Studies in people and animals

Animal and lab results

In rats and mice, pectins from various sources lowered fasting blood sugar, insulin and the blood sugar rise after a starch meal. Lab tests showed pectin can inhibit amylase enzymes and coat starch granules, though some pectins enhanced amylase activity instead.

What the authors conclude

“Pectins can favorably regulate in vivo starch digestion and blood glucose level responses, and these effects are attributed to several reasons: increasing the viscosity of digesta, inhibiting amylase activity, and regulating some in vivo physiological responses.”
Bai Y, Gilbert RG, 2022

Also in their conclusions

  • They conclude that pectin usually slows starch digestion and flattens the blood sugar rise, through increased viscosity, amylase inhibition and gut physiological responses.
  • They advise that future studies should report pectin's structural details, such as its degree of esterification and molecular size, so results can be compared.
  • They suggest pectins with the right structure could be used to design low glycemic-response foods without the unpleasant high viscosity of many other fibres.

How it was done

Obesity and type II diabetes are closely tied to fast starch digestion, and pectin is a common food fibre that may help control blood sugar. The authors wanted to pull together decades of findings, since earlier work often ignored how pectin's structure affects its behaviour.

The authors reviewed human studies, rodent studies and lab experiments on pectin and starch digestion. Human studies included healthy volunteers, people with diabetes and people who had gastric surgery, given pectin with meals or glucose drinks. Rodent and lab work covered many pectin types, doses and diets.

What it can’t tell you

  • Many of the findings come from animals or lab tests, so they cannot show what happens in people.
  • Human studies used different pectin types, doses and meals, so the size of the effect in any one food is not settled.
  • The review cannot say whether eating pectin regularly changes long-term health outcomes like diabetes risk.

The paper

Title
Mechanistic Understanding of the Effects of Pectin on In Vivo Starch Digestion: A Review
Type
ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
Evidence
Studies in people · animals · lab
Summarised from
Full text
Cite
Bai Y, Gilbert RG (2022). Mechanistic Understanding of the Effects of Pectin on In Vivo Starch Digestion: A Review. Nutrients. doi:10.3390/nu14235107Free full textPubMed 36501138DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error