Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

A sugar called fructose is found naturally in fruit, and is used in soft drinks, bread and many other sweetened foods.

A sugar called fructose is found naturally in fruit, and is used in soft drinks, bread and many other sweetened foods. Credit: Getty

Metabolism

How the body battles a spoonful of sugar

The gut is the first line of defence.

The small intestine helps to shield the liver from damage caused by a common sugar — but the defence system fails when large amounts are consumed.

Joshua Rabinowitz at Princeton University in New Jersey and his colleagues sought to trace the fate of fructose, a sugar found in fruit and sweetened products such as soft drinks. The researchers fed fructose labelled with a heavy isotope of carbon to mice and tracked the signal. This revealed that when fructose is eaten in modest amounts, it is converted in the small intestine into the simple sugar glucose.

But when mice ate large amounts of fructose — the equivalent of about half a can of soft drink for a human — the sugar overwhelmed the small intestine, forcing some of the fructose to be processed in the liver, where the sugar has a toxic effect. This spillover to the liver was lessened if the sugar was eaten on a full stomach.

More Research Highlights...

Pulsar wind nebula illustration

Curving purple lines in this artist’s impression represent the magnetic field of a neutron star (white sphere) left over from a brilliant supernova. Credit: Salvatore Orlando/INAF-Osservatorio Astronomico di Palermo

Astronomy and astrophysics

X-rays expose a clue to the mystery of the missing neutron star

Astronomers might have spotted the long-sought debris of a famous stellar explosion.
A bone fragment next to a dime

A bone fragment excavated in Southeast Alaska belonged to one of the earliest known domestic dogs in the Americas. Credit: Douglas Levere/University at Buffalo

Genomics

An ancient Alaskan dog’s DNA hints at an epic shared journey

To scientists’ surprise, a 10,000-year-old bone found in an Alaskan cave belonged to a domestic dog — one of the earliest known from the Americas.
Emissions billow from smokestacks at a coal-fired power plant as the sun sets, India.

Black carbon emitted by power plants and other sources in Asia wafts to the Arctic, where the pollution accelerates the melting of ice and snow. Credit: Kuni Takahashi/Bloomberg/Getty

Atmospheric science

Soot from Asia travels express on a highway to the high Arctic

Black carbon from fuel combustion in South Asia bolsters the effects of climate change on northern ice and snow.
Prevotella copri bacteria, computer illustration

The gut bacterium Prevotella copri (artist’s impression) has been linked to a reduction in the health benefits of a diet that skimps on red meat in favour of fish and vegetables. Credit: Kateryna Kon/Science Photo Library

Microbiology

Trying a Mediterranean diet? Gut microbes might sway the outcome

The composition of a person’s microbiome could influence the health effects of swapping steak for vegetables and olive oil.
Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing

Search

Quick links