The researchers report that in mice, fructose, a sugar found in fruit, is processed mainly in the small intestine, not in the liver as had previously been suspected. Sugary drinks and processed high-sugar foods overwhelm the small intestine and spill into the liver for processing. Additionally, the authors learned that the ability of the small intestine to process fructose is higher after a meal. The work appears in the journal Cell Metabolism.
Evidence from previous animal and human studies has shown that excessive sugar ingestion can be harmful, especially to the liver. Chronic over-consumption can lead to obesity and foster insulin resistance that can progress to diabetes; it also can contribute to non-alcoholic fatty liver disease, which can lead to cirrhosis or liver cancer.
"There is a fundamental physiological difference in how smaller and larger amounts of sugar are processed in the body," explains the senior author. The prior view was that the liver processes all ingested sugar. But this study showed that more than 90 percent of the fructose was cleared by the small intestine in mice.
"We can offer some reassurance--at least from these animal studies--that fructose from moderate amounts of fruits will not reach the liver," senior author says. However, the small intestine probably starts to get overwhelmed with sugar halfway through a can of soda or large glass of orange juice.
In the study, researchers studied the path of isotope-labeled fructose through the digestive systems of laboratory mice. The researchers observed that excess fructose that is not absorbed by the small intestine continues through the intestine into the colon. As a consequence, it also comes into contact with the natural microbiotic flora of the large intestine and colon, known as the microbiome.
"The microbiome is designed to never see sugar," senior author says. "One can eat an infinite amount of carbohydrates, and there will be nary a molecule of glucose that enters the microbiome. But as soon as you drink the soda or juice, the microbiome is seeing an extremely powerful nutrient that it was designed to never see."
While the study did not show that fructose influences the microbiome, the authors suggest an effect is likely and should be studied further to learn more about the biological consequences of high sugar intake.
The investigators also found that the small intestine clears fructose more efficiently after a meal. "We saw that feeding of the mice prior to the sugar exposure enhanced the small intestine's ability to process fructose," said senior author. "And that protected the liver and the microbiome from sugar exposure." The researchers theorize that in a fasting state, such as upon awakening or in the mid-afternoon, one is extra vulnerable to fructose due to a lessened ability to process it in the small intestine.
Although the study was conducted in mice, senior author encourages "the most old-fashioned advice in the world" for humans. Limit sweets to moderate quantities after meals, and do not have sweet drinks away from meal time.
http://www.cell.com/cell-metabolism/fulltext/S1550-4131(17)30729-5
Its small intestine, not liver clears dietary fructose
- 2,620 views
- Added
Edited
Latest News
More influence of environme…
By newseditor
Posted 24 Apr
The assembly of the human c…
By newseditor
Posted 24 Apr
Wiring of the human neocortex
By newseditor
Posted 24 Apr
Abusive drugs hijack natura…
By newseditor
Posted 23 Apr
Mechanism of action of the…
By newseditor
Posted 23 Apr
Other Top Stories
Facioscapulohumeral muscular dystrophy (FSHD) mouse model developed!
Read more
How eyes get clogged in glaucoma
Read more
Animal model for bipolar disorder?
Read more
Converting bad body fat into good fat
Read more
Key regulator of male fertility identified!
Read more
Protocols
A programmable targeted pro…
By newseditor
Posted 23 Apr
MemPrep, a new technology f…
By newseditor
Posted 08 Apr
A tangible method to assess…
By newseditor
Posted 08 Apr
Stem cell-derived vessels-o…
By newseditor
Posted 06 Apr
Single-cell biclustering fo…
By newseditor
Posted 01 Apr
Publications
Distinct genetic and enviro…
By newseditor
Posted 24 Apr
Hippocampus-to-amygdala pat…
By newseditor
Posted 24 Apr
Integrative spatial analysi…
By newseditor
Posted 24 Apr
Time-series reconstruction…
By newseditor
Posted 24 Apr
Harnessing gastrointestinal…
By newseditor
Posted 24 Apr
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar