Added fructose principal driver of diabetes and pre-diabetes

Added-fructoseWASHINGTON: Added sugars, particularly those containing fructose, are a principal driver of diabetes and pre-diabetes, even more so than other carbohydrates, a new study has warned.

“At current levels, added-sugar consumption, and added-fructose consumption in particular, are fuelling a worsening epidemic of type 2 diabetes,” said lead author James J DiNicolantonio, a cardiovascular research scientist at Saint Luke’s Mid America Heart Institute, Kansas City.

DiNicolantonio and team writing in the journal Mayo Clinic Proceedings challenge current dietary guidelines that allow up to 25 per cent of total daily calories as added sugars, and propose drastic reductions in the amount of added sugar, and especially added fructose, people consume.

The net result of excess consumption of added fructose is derangement of both overall metabolism and global insulin resistance, researchers said.

Other dietary sugars not containing fructose seem to be less detrimental in these respects.
Indeed, several clinical trials have shown that compared to glucose or starch, isocaloric exchange with fructose or sucrose leads to increases in fasting insulin, fasting glucose, and the insulin/glucose responses to a sucrose load, researchers added.

“This suggests that sucrose (in particular the fructose component) is more harmful compared to other carbohydrates,” said DiNicolantonio.

DiNicolantonio and his co-authors examined animal experiments and human studies to come to their conclusions.

Data from recent trials suggest that replacing glucose-only starch with fructose-containing table sugar (sucrose) results in significant adverse metabolic effects.

Adverse effects are broader with increasing baseline insulin resistance and more profound with greater proportions of added fructose in the diet.

The totality of the evidence is compelling to suggest that added sugar, and especially added fructose (usually in the form of high-fructose corn syrup and table sugar), are a serious and growing public health problem, researchers said.

‘Feeding & fasting’ hormone
Meanwhile, scientists say in another study that a hormone that maintains metabolic health can improve insulin action in obese, diabetic mice, paving the way for new therapies to treat type 2 diabetes.

Andrew Butler, professor of pharmacological and physiological science at Saint Louis University, and his lab discovered the peptide hormone adropin several years ago.

Adropin regulates whether the body burns fat or sugar during feeding and fasting cycles.
“Adropin is a poorly understood hormone,” Butler said.

“We first reported its discovery a little over six years ago, but we really didn’t understand what it did. We knew it played a role in maintaining metabolic health, but we didn’t know much beyond that,” he added.

In a recent paper published in the journal Diabetes, Butler and team offered the first definition of adropin’s functions that maintain metabolic health.

“When we measured adropin levels in mice, they were suppressed under fasting conditions and stimulated after feeding, suggesting functions related to the changes in metabolism that occur with feeding and fasting,” Butler said.

“Our work suggests that adropin plays a role in regulating metabolic (energy) homeostasis,” Butler added.

“Basically, when you are well fed, your body prefers to use glucose and the release of adropin supports this change by enhancing the use of glucose as a metabolic fuel in muscle.

“However, when you are fasting, your body prefers to use fatty acids. Our observations suggest that a decline in adropin with fasting may be a signal to “take the brakes off” the use of fatty acids,” Butler said.

Building on that work, researchers in a new paper in the journal Molecular Metabolism reported that low levels of the hormone observed in obesity may contribute to diabetes and the reduced ability of the body to use glucose.

The team found that treatment with adropin improved glucose tolerance, enhanced insulin action and improved metabolic flexibility toward glucose utilization in situations of obesity and insulin resistance.

“The hope is that adropin could someday be used in the clinic to help patients with type 2 diabetes control blood sugar levels and delay or prevent the development of the disease in at-risk individuals,” Butler said.-PTI