A Teaspoon of Agavin

Sept. 12, 2014

By Medical Discovery News

Agave plant

Next time you have a bitter pill to swallow, think about reaching for a spoonful of agavin instead of sugar to help the medicine go down. You might not know what agavin is yet, but you’ve probably noticed that a number of alternative natural sweeteners like Stevia have been added to grocery store shelves next to traditional sugar. These products sweeten foods but often do not add calories or raise blood sugar levels. Recent research suggests that a sweetener made from agave, the same plant used to make tequila, may lower blood sugar levels and help people maintain a healthy weight.

Agavin is a natural form of sugar, fructose, called fructan. With fructan, individual sugar molecules are linked together in long chains. The human body cannot use this form of fructose, so it is a nondigestible dietary fiber that does not contribute to blood sugar levels. But it can still add sweetness to foods and drinks. Alternatively, agave syrup or nectar, while made from the same plant, contains fructan that has been broken down into individual fructose molecules so it does affect caloric intake and blood sugar levels.

Studies of mice prone to diet-induced obesity and type 2 diabetes found that when they consumed agavin, they ate less and had lower blood glucose levels, increased insulin, and more glucagon-like peptide-1 (GLP-1). GLP-1 is a hormone that inhibits gastrointestinal motility, which causes people to eat less because they feel fuller. It also stimulates the production of insulin. GLP-1 appears to be a regulator of appetite and food intake, and so it is being evaluated as a therapy for type 2 diabetes.

Further testing showed that when agavin was added to the water supply of mice eating a normal diet, they ate less, lost weight, and had lower blood glucose levels compared with mice that consumed other sugars such as glucose, fructose, sucrose, agave syrup, and the artificial sweetener aspartame. While these results are encouraging, the studies need to be replicated and then done using humans for agavin’s effectiveness to be proven. The possible long-term consequences of its use must also be examined. So far, the only known down sides are that agavin is not yet widely available and that it is not as sweet as sucrose or artificial sweeteners.

Agavin would join other natural sweeteners that do not add calories or affect blood sugar such as stevia, which is currently found in a variety of products. The stevia plant is native to Paraguay, where its leaves have been used as a sweetener for over a century. Stevia has been the subject of biological and toxicological studies for more than 50 years and its safety is well-established. It stimulates the pancreas to secrete insulin, a benefit to diabetics, and does not alter the naturally-occurring, beneficial bacteria in the digestive tract.

Thanks to agavin and other natural sweeteners, people with diabetes (or anyone watching their caloric and sugar intake) now have more choices than ever for sweeteners and products made with them, so they can eat or drink without raising their blood sugar levels. Agavin: it’s not just for tequila anymore.

For a link to this story, click here.

Bear-ly Understanding Diabetes

May 30, 2014

By Medical Discovery News

What can studying grizzly bears reveal about human diabetes?

While they are some of the largest bears on earth, Grizzly bears aren’t usually accused of being fat. Regardless, these animals are helping scientists discover new and better treatments for human obesity and diabetes.

Grizzlies spend the late summers consuming more than 50,000 calories per day. As a comparison, a moderately active 50-year-old human female is recommended 2,300. Grizzlies then hibernate for up to seven months, relying on the pounds of stored fat they accumulated before winter. While hibernating, bears do not eat, urinate, or defecate. 

Scientists wondered if all the weight and fat bears gain results in diabetes like it does in humans. Overweight people face an increased risk of type 2 diabetes, in which the body does not make enough of the hormone insulin or cells do not respond to it. Insulin helps move a type of sugar called glucose from the blood into cells, where it is used for energy and as a precursor for other molecules the body needs. If sugar levels in the blood remain elevated and the body doesn’t have enough insulin, cells are starved for energy, leading to damaged eyes, kidneys, nerves, and hearts. 

Interestingly, Grizzly bears can actually control their insulin responsiveness. When they are the fattest, they are most sensitive to insulin, thereby keeping their blood sugar levels healthy. Soon after going into hibernation, they switch to complete insulin resistance, meaning they develop type 2 diabetes. But unlike humans, their blood sugar levels remain normal. When they awaken in the spring, their insulin responsiveness is restored. Bears do this not so much to regulate their blood sugar levels as to regulate their storage and utilization of fat. So how do bears control their insulin responsiveness? And could it lead to new treatments for type 2 diabetes in humans?

PTEN is a protein that regulates cells’ sensitivity to insulin. Scientists know exactly when Grizzlies increase or decrease PTEN activity, they just don’t know how. People with a PTEN mutation have a metabolism similar to Grizzlies’.  These people have an increased risk of obesity and cancer but a decreased risk of developing type 2 diabetes because they are more sensitive to insulin.

Grizzlies have also evolved to the ability to accumulate large amounts of fat only in their adipose tissue, just below the skin so it doesn’t interfere with the rest of their bodies. In humans, on the other hand, fat can accumulate in many places like the liver, in muscles, and around other internal organs, which are all highly unhealthy places to keep fat. Bears can also have elevated levels of cholesterol without the serious consequences of cardiovascular disease.

During hibernation, the Grizzly bears’ kidneys shut down. But despite the high levels of toxins that accumulate in the blood without working kidneys, they don’t die or even suffer from it like a human would. When they wake up, their kidney function is restored with no permanent damage.

After millions of years of evolution, Grizzly bears and other animals have developed solutions for biological challenges humans still face. Studying them is a new approach that has the potential to create treatments for many human conditions.

For a link to this story, click here.