Fructose

Studies in people

• Open question

  Appetite and fullness³

  In studies in people and animals, whether fructose affects fullness differently than glucose is unclear, and the evidence is not strong.

• Concern

  Liver fat production⁴

  In healthy men, drinks sweetened with fructose or sucrose made the liver build more fat than glucose drinks did.

• Concern

  Sugary drinks and blood pressure⁵

  Fructose from sugary drinks, not fruit, was linked to higher blood pressure in people.

• Concern

  Liver fat and blood sugar¹¹

  In people, two weeks of drinks sweetened with high fructose corn syrup raised liver fat and lowered insulin sensitivity.

• Open question

  Blood sugar during exercise¹²

  Fructose eaten before exercise kept blood sugar steadier than glucose and worked just as well.

• Concern

  Body fat distribution¹³

  In this study, fructose intake was linked to arm fat in women and men, and to belly fat in younger men.

• Concern

  Heart and blood pressure risk¹⁴

  Fructose from sugary drinks and foods was linked to higher homocysteine, which may help explain heart and blood pressure risks.

• Open question

  Sugar in breast milk¹⁶

  In breastfeeding women, a high-fructose corn syrup drink raised breast milk fructose for up to five hours.

Animal and lab studies only

• Concern

  Tumour growth²⁴

  In animal studies, fructose boosted tumour growth by raising certain fats in the blood, not by feeding tumours directly.

• Concern

  Brain development in young animals²⁵

  In animal studies, young mice given lots of fructose grew up with anxious behaviour, and their brain's cleanup cells worked less.

• Concern

  Body fat gain²⁶

  In animal studies, fructose promotes fat tissue buildup by turning on fat-making processes.

• Benefit

  Colon cancer growth²⁷

  In animal studies, resistant starch stopped high-fructose corn syrup from feeding colon tumours.

• Concern

  Slow eating protects liver²⁸

  In animal studies, fructose eaten slowly caused less liver fat than the same amount drunk quickly.

• Concern

  Liver fat buildup²⁹

  In animal studies, fructose helped build up liver fat when mice were fed a high-fructose diet.

Study type not stated

• Concern

  Sugar and heart risk¹⁷

  Eating too much fructose may raise the risk of obesity and heart-related disease, though scientists are still working out how.

• Concern

  Fatty liver disease¹⁸

  Fructose in sugary drinks and added sugars is strongly linked to fat building up in the liver.

• Concern

  Liver insulin resistance¹⁹

  Fructose, not glucose, in sugary drinks and food drives liver insulin resistance, even without extra weight gain.

• Concern

  Fat storage and metabolic health²⁰

  Fructose is a sugar that can drive fat buildup, insulin resistance and fatty liver when eaten in excess.

• Concern

  Belly fat around organs²¹

  Scientists think eating lots of fructose may cause inflammation that leads to fat building up around organs.

• Concern

  Cancer growth²²

  Fructose may help cancer grow, but scientists do not yet know exactly how.

• Concern

  Blood pressure and salt²³

  Eating lots of fructose along with salt makes the kidneys hold onto salt, which can raise blood pressure.

Allergies and intolerances

These are about people with an allergy, an intolerance or coeliac disease. The signal is about the ingredient itself, and these are about the person eating it, so the signal does not count them.

• Gut symptoms and bloating⁷

  In some people, fructose is not fully absorbed and may be linked to stomach pain and diarrhea.

• Inherited sugar intolerance⁸

  People born with fructose intolerance get low blood sugar and bad stomach problems after eating fructose.

• Gut symptoms from sugars⁹

  Fructose malabsorption can lead to intestinal symptoms.

• Rare sugar intolerance¹⁰

  People born with hereditary fructose intolerance can get dangerously low blood sugar after eating fructose.

How it’s made and used

• Gut absorption of sugars⁶

  Your gut absorbs fructose poorly on its own, but eating glucose alongside fructose helps it get taken in.

• Fuel use during exercise¹⁵

  In trained cyclists, fructose with glucose during long rides raised carbohydrate burning.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.