Could high insulin make you fat? Mouse study says yes
When we eat too much, obesity may develop as a result of chronically high insulin levels, not the other way around. That's according to new evidence in mice reported in the December 4th Cell Metabolism, a Cell Press publication, which challenges the widespread view that rising insulin is a secondary consequence of obesity and insulin resistance. Credit: Mehran et al., Current Biology
When we eat too much, obesity may develop as a result of chronically high insulin levels, not the other way around. That's according to new evidence in mice reported in the December 4th Cell Metabolism, a Cell Press publication, which challenges the widespread view that rising insulin is a secondary consequence of obesity and insulin resistance.
The new study helps to solve this chicken-or-the-egg dilemma by showing that animals with persistently lower insulin stay trim even as they indulge themselves on a high-fat, all-you-can-eat buffet. The findings come as some of the first direct evidence in mammals that circulating insulin itself drives obesity, the researchers say.
The results are also consistent with clinical studies showing that long-term insulin use by people with diabetes tends to come with weight gain, says James Johnson of the University of British Columbia.
"We are very inclined to think of insulin as either good or bad, but it's neither," Johnson said. "This doesn't mean anyone should stop taking insulin; there are nuances and ranges at which insulin levels are optimal."
Johnson and his colleagues took advantage of a genetic quirk in mice: that they have two insulin genes. Insulin1 shows up primarily in the pancreas and insulin2 in the brain, in addition to the pancreas. By eliminating insulin2 altogether and varying the number of good copies of insulin1, the researchers produced mice that varied only in their fasting blood insulin levels. When presented with high-fat food, those with one copy and lower fasting insulin were completely protected from obesity even without any loss of appetite. They also enjoyed lower levels of inflammation and less fat in their livers, too.
Those differences traced to a "reprogramming" of the animals' fat tissue to burn and waste more energy in the form of heat. In other words, the mice had white fat that looked and acted more like the coveted, calorie-burning brown fat most familiar for keeping babies warm.
Johnson says it isn't clear what the findings might mean in the clinic just yet, noting that drugs designed to block insulin have been shown to come with unwanted side effects. But, he added, "there are ways to eat and diets that keep insulin levels lower or that allow insulin levels to return to a healthy baseline each day."
Unfortunately, constant snacking is probably not the answer.
More information: Mehran et al.: "Hyperinsulinemia drives diet-induced obesity independently of brain insulin production." Cell Metabolism, DOI: 10.1016/j.cmet.2012.10.019
Provided by Cell Press
- Improving obesity-induced insulin sensitivity Jun 01, 2012 | not rated yet | 0
- Understanding insulin resistance; Precursor to diabetes can be reversed Nov 06, 2012 | not rated yet | 0
- Drugs that act on 'fasting signal' may curb insulin resistance in obese Mar 03, 2009 | not rated yet | 0
- Apelin hormone injections powerfully lower blood sugar Nov 04, 2008 | not rated yet | 0
- Enzyme boosts metabolism, prevents weight gain in mice Nov 14, 2011 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013 Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
By discovering the new mechanism by which estrogen suppresses lipid synthesis in the liver, UC Irvine endocrinologists have revealed a potential new approach toward treating certain liver diseases.
Medical research 18 hours ago | not rated yet | 0 |
Aortic arch pulse wave velocity, a measure of arterial stiffness, is a strong independent predictor of disease of the vessels that supply blood to the brain, according to a new study published in the June issue the journal ...
Medical research 18 hours ago | not rated yet | 0
Since the discovery of Prontosil in 1932, sulfonamide antibiotics have been used to combat a wide spectrum of bacterial infections, from acne to chlamydia and pneumonia. However, their side effects can include serious neurological ...
Medical research 19 hours ago | not rated yet | 0 |
Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as ...
Medical research 19 hours ago | 5 / 5 (2) | 0 |
Spanish researchers have discovered that the daily clearance of neutrophils from the body stimulates the release of hematopoietic stem cells from the bone marrow into the bloodstream, according to a report published today ...
Medical research 21 hours ago | 5 / 5 (2) | 0
(Medical Xpress)—A new study by researchers in the US has shown that an ancient virus can be modified to help in the fight against the simian immunodeficiency virus SIV, which is the equivalent in monkeys ...
40 minutes ago | not rated yet | 0 |
How can healthy people who hear voices help schizophrenics? Finding the answer for this is at the centre of research conducted at the University of Bergen.
32 minutes ago | 3 / 5 (1) | 0
Researchers from London's Kingston University have begun a two-year study which could help prolong the lives of people with colorectal tumours.
22 minutes ago | not rated yet | 0
New research presented today shows that formation of new neurons in the hippocampus - a brain region known for its importance in learning and remembering - could cause forgetting of old memories by causing a reorganization ...
12 minutes ago | not rated yet | 0
Ernie Pyle – an iconic war correspondent in World War II – reportedly said "There are no atheists in foxholes." A new joint study between two brothers at Cornell and Virginia Wesleyan found that only ...
15 minutes ago | not rated yet | 0
(Medical Xpress)—Research by Stanford scholar Emma Seppala at the Center for Compassion and Altruism Research and Education found that post-traumatic stress disorder decreased in veterans who participated ...
42 minutes ago | not rated yet | 0