Understanding Diabetes, Part 1

By Nancy Sauer, Bakery Manager

This spring Open Harvest sponsored a cooking class calledDelicious Diabetic Dining. The interest in the classes and the questionsasked during them showed that there is a desire for informationabout what diabetes is and how one lives with it. The aim ofthis article is to provide a basic overview of what's known aboutdiabetes.

Diabetes is the name of a group of diseases in which the bodydoes not make or use insulin properly. Insulin is the hormoneresponsible for moving glucose, or sugar, out of the bloodstreamand into the muscle and organ cells that need it. Glucose is thebody's main energy source. One of the tasks of the digestivesystem is to break down the carbohydrates we eat and transformthem into glucose. This is then absorbed by the blood andcirculated through the body. If something happens to disrupt thebody's insulin supply our cells go hungry while unused glucosebuilds up in the blood stream.

The two major varieties of diabetes are Type 1, in which thebody is completely unable to manufacture insulin, and Type 2, inwhich the body either doesn't manufacture enough insulin or doesnot use insulin effectively. There is a third type of diabetes, gestationaldiabetes, which is a temporary condition affecting somewomen during pregnancy. Gestational diabetes usually goes awayafter the pregnancy, but women who have had it have a greaterrisk of developing Type 2 diabetes later in life.

Type 1 diabetes was once called juvenile-onset diabetesbecause it most often develops in children, teenagers and youngadults. In this kind of diabetes, the islets, the special cells in thepancreas that manufacture insulin, have been completely destroyedleaving the person with no insulin at all. Persons with thistype of diabetes must take insulin to regulate their blood glucoseand so Type 1 is sometimes called insulin-dependent diabetes.About 5-10 percent of diabetics in the US have Type 1.

Type 2 diabetes was once called adult-onset diabetes becauseit was usually diagnosed in middle-aged or older adults. In thiskind of diabetes the islets still make insulin but either they don'tmake enough or the body's cells don't use it efficiently. Some Type2 diabetics need insulin to control their blood glucose but mostcan manage it effectively with medications that help the body touse its own insulin. For this reason Type 2 is sometimes referredto as non-insulin dependent diabetes. About 90-95 percent ofdiabetics in the US have Type 2.

At this point, both forms of diabetes are chronic diseases -they can be treated, but not cured. But the Diabetes PreventionProgram sponsored by the National Institutes of Health has shownthat it is possible to prevent or delay the development of Type 2 inpersons who are at risk. By exercising 30 minutes a day five timesa week and losing 5-10% of body weight (if one is overweight)you can reduce your risk of developing Type 2 diabetes. And sinceexercise and keeping a healthy weight also reduces your chancesof heart disease and cancer, this is an all-around a good deal.See page 8 to learn about the new Diabetes Support Group.

Understanding Diabetes, Part 2

In this part will be a look at the causes of Type 1 andwhat research is being done on prevention or cures for it.Type 2 will be covered in part 3.

Type 1 diabetes is an autoimmune disease - one of thediseases caused by the body's immune system mistakingnormal body tissue as an invader and attacking it.Systemic lupus erythematosus, rheumatoid arthritis, andceliac sprue are other examples of autoimmune diseases.In the case of Type 1, the insulin-producing beta-cells inthe part of the pancreas known as islets are targeted asenemies and destroyed.

By studying the incidence of Type 1 in different populations,certain patterns have emerged. Type 1 is morecommon in Caucasians than in other ethnic groups, withthe highest rates being found in the Scandinavian countriesand Sardinia, Italy. This is evidence that part of thecause is genetic. However, studies done of identical twinshave shown that genetics is not enough - when one twinhas Type 1 diabetes, only about 30% of the cases doesthe other twin have it. This has led researchers to lookfor environmental triggers to the disease, and there isevidence that viruses, diet, or both may play a role. Thereis a great deal of research being done on the question ofwhat exact combination of genes and environmental factorstrigger Type 1.

Research on the prevention or cure of Type 1 is goingon in many different areas, and the two issues aresomewhat linked. Ultimately, a cure involves restoringthe body's ability to make insulin. Transplants of wholepancreases or islet cells, or regrowing new islets from thepatient's own cells would all in theory work, and all threeareas are being investigated. But as long as the patient'simmune system regarded the new beta cells as invadersthis would only be a temporary treatment, and so researchis also being done to understand why and how theimmune system loses its ability to distinguish friend fromfoe. This information would in turn allow the possibilityof stopping the immune system's attack on the beta cellsbefore it went to completion, thus preventing Type 1 fromdeveloping at all.

Understanding Diabetes, Part 3

The causes of Type I diabetes areonly partially known: It is clear that itis an autoimmune disease, but whatcauses the body to regard its pancreaticcells as an enemy is unknown. Type IIdiabetes is even more mysterious. It ischaracterized by the cells of the bodybecoming resistant to insulin, but howand why this occurs is unknown.

Some, but not all, Type II diabeticsalso have failure of the insulin-producingbeta cells of their pancreas, andsome but not all of them show the sameimmune responses as Type I diabetics.These observations, along with developingresearch on possible genetic andnon-genetic causes of Type II, have ledresearchers to the possibility that Type II diabetes maynot be a single disease but a family of diseases with differentcauses but similar symptoms.

The one thing that is clear is that medical researchhas a long way to go before we understand the causes ofthis disease.

Even with our current limited understanding, however,some things are clear. Obesity is apparently a risk factor,as is a lack of physical activity. This can be seen, somewhattragically, in the recent upswing of Type II diabetesin children in the US. On the positive side, this points toways that individuals can act to reduce their risk of developingType II diabetes.

The Diabetes Prevention Program,a three year large-scale researchstudy sponsored by the National Instituteof Health, showed that people atrisk of diabetes could delay or preventonset by means of simple life-stylechanges. Participants in the studygroup who exercised for at least 30minutes a day, five days a week andwho received counseling on healthyeating choices reduced their risk ofdeveloping diabetes by 58% comparedto the control group.

Based on this research the NationalInstitutes of Health have issuedsome guidelines for Americans whowant to reduce their risk of diabetes:

1. Eat a sensible diet that emphasizes fruits, vegetables,and whole grains.
2. Exercise at least 30 minutes a day five days aweek. An elaborate exercise program isn't necessary, justwalking will do fine.
3. If you are overweight, losing weight will helpreduce your risk. You don't have to lose all your excessweight at once; losing just 5 to 10% of your body masswill lower your risk.

More complete information on the Diabetes PreventionProgram and the National Institute of Health's recommendationscan be found at: http://www.ndep.nih.gov/campaigns/SmallSteps/SmallSteps_index.htm