Toronto does it again…

…in diabetes research.

First there were Frederick Banting and Charles Best, with their discovery of insulin as an effective treatment for diabetes (mostly for type 1, although some type 2 sufferers also depend on it). They made that discovery at U of T.

Now, researchers at Sick Kids think they may be onto something even more exciting. Not a treatment, but a CURE:

In a discovery that has stunned even those behind it, scientists at a Toronto hospital say they have proof the body’s nervous system helps trigger diabetes, opening the door to a potential near-cure of the disease that affects millions of Canadians.

Diabetic mice became healthy virtually overnight after researchers injected a substance to counteract the effect of malfunctioning pain neurons in the pancreas.

“I couldn’t believe it,” said Dr. Michael Salter, a pain expert at the Hospital for Sick Children and one of the scientists. “Mice with diabetes suddenly didn’t have diabetes any more.”

[…]

“I’ve never seen anything like it,” said Dr. Hans Michael Dosch, an immunologist at the hospital and a leader of the studies. “In my career, this is unique.”

Their conclusions upset conventional wisdom that Type 1 diabetes, the most serious form of the illness that typically first appears in childhood, was solely caused by auto-immune responses — the body’s immune system turning on itself.

They also conclude that there are far more similarities than previously thought between Type 1 and Type 2 diabetes, and that nerves likely play a role in other chronic inflammatory conditions, such as asthma and Crohn’s disease.

[…]

About two million Canadians suffer from diabetes, 10% of them with Type 1, contributing to 41,000 deaths a year.

Insulin replacement therapy is the only treatment of Type 1, and cannot prevent many of the side effects, from heart attacks to kidney failure.

In Type 1 diabetes, the pancreas does not produce enough insulin to shift glucose into the cells that need it. In Type 2 diabetes, the insulin that is produced is not used effectively — something called insulin resistance — also resulting in poor absorption of glucose.

The problems stem partly from inflammation — and eventual death — of insulin-producing islet cells in the pancreas.

Dr. Dosch had concluded in a 1999 paper that there were surprising similarities between diabetes and multiple sclerosis, a central nervous system disease. His interest was also piqued by the presence around the insulin-producing islets of an “enormous” number of nerves, pain neurons primarily used to signal the brain that tissue has been damaged.

Suspecting a link between the nerves and diabetes, he and Dr. Salter used an old experimental trick — injecting capsaicin, the active ingredient in hot chili peppers, to kill the pancreatic sensory nerves in mice that had an equivalent of Type 1 diabetes.

“Then we had the biggest shock of our lives,” Dr. Dosch said. Almost immediately, the islets began producing insulin normally “It was a shock — really out of left field, because nothing in the literature was saying anything about this.”

It turns out the nerves secrete neuropeptides that are instrumental in the proper functioning of the islets. Further study by the team, which also involved the University of Calgary and the Jackson Laboratory in Maine, found that the nerves in diabetic mice were releasing too little of the neuropeptides, resulting in a “vicious cycle” of stress on the islets.

So next they injected the neuropeptide “substance P” in the pancreases of diabetic mice, a demanding task given the tiny size of the rodent organs. The results were dramatic.

The islet inflammation cleared up and the diabetes was gone. Some have remained in that state for as long as four months, with just one injection.

They also discovered that their treatments curbed the insulin resistance that is the hallmark of Type 2 diabetes, and that insulin resistance is a major factor in Type 1 diabetes, suggesting the two illnesses are quite similar.

While pain scientists have been receptive to the research, immunologists have voiced skepticism at the idea of the nervous system playing such a major role in the disease. Editors of Cell put the Toronto researchers through vigorous review to prove the validity of their conclusions, though an editorial in the publication gives a positive review of the work.

“It will no doubt cause a great deal of consternation,” said Dr. Salter about his paper.

It also makes me wonder if people who love their hot peppers–like me–are naturally less susceptible to diabetes of both types, since capsaicin is a natural painkiller and travels everywhere in the body via the bloodstream (ask anyone who eats chillies just to get that hot, hot natural high. For that matter, just ask me–I eat it for my rheumatism, which I’ve had since I was 15.)

It stands to reason that a good portion of the capsaicin we eat would land up in the pancreas, quite possibly very soon after ingestion. That would have a powerful prophylactic effect against diabetes, and it would be so easy to incorporate into anyone’s daily diet, too.

Whatever else may come of it, this research has opened up multiple–and intriguing–possibilities.