Prevention of Type 2 Diabetes - PART 1

By Paul E. Lemanski, MD, MS, FACP

Editor’s Note: This is the 83rd in a series on optimal diet and lifestyle to help prevent and treat disease. Any planned change in diet, exercise or treatment should be discussed with and approved by your personal physician before implementation. The help of a registered dietitian in the implementation of dietary changes is strongly recommended.

Medicines are a mainstay of American life and the healthcare system, not only because they are perceived to work by the individuals taking them, but also because their benefit may be shown by the objective assessment of scientific study. Clinical research trials have shown that some of the medicines of Western science may reduce the risk of heart attacks, strokes and cardiovascular death, while others may reduce certain types of cancer.

In the first 82 installments of the Non-Medicated Life, informed diet and lifestyle have been shown to accomplish naturally for the majority of individuals, many, if not most of the benefits of medications in the prevention and treatment of chronic medical conditions. Moreover, as a medical intervention they may accomplish such benefits with fewer side effects, may reduce the number and amount of medication, and may allow actual discontinuation of medication. However, in some cases informed diet and lifestyle prove superior to medication. This is especially true for the prevention and remission of type 2 diabetes mellitus. 

This is Part One to address prevention of type 2 diabetes. Part Two, in the August 2018 issue, will address remission of type 2 diabetes.

PREVENTION

Type 2 diabetes is a disease characterized by insulin resistance. Individuals with type 2 diabetes, unlike individuals with type 1 diabetes, have sufficient insulin but that insulin does not work properly. Insulin is a hormone produced by islet cells in the pancreas. Insulin is needed for the transfer of glucose from the blood stream in to the cells of the body; the only exception to this is the brain. It is sometimes helpful to think of insulin as the activator of a pump on the surface of cells which takes glucose from the bloodstream and brings it in to the cell. Each cell has a receptor for insulin on its surface. The pump is activated when a molecule of insulin enters the receptor.

In individuals with prediabetes (and diabetes), there is a change in the shape of the receptor, which requires more insulin to achieve activation of the pump. In an attempt to control blood sugar, excess levels of insulin in the blood is required, and the pancreas must increases insulin production markedly. Over the years, this excess insulin production overworks the islet cells of the pancreas causing them to burn out. By the time a diagnosis of type 2 diabetes is made, an elevated fasting blood sugar (or elevated hemoglobin ALc), 50 to 70% of the islet cells may be lost to such burnout. Since islet cells, once lost, cannot be replaced it is important to know if there is a way to prevent their loss in the first place. Thankfully there is.

Pre-diabetes is a condition brought about by increase in bodyweight in individuals with a genetic predisposition for diabetes. A genetic predisposition is conferred by a family history of type 2 diabetes. In a study done a number of years ago called the Diabetes Prevention Program, individuals who were pre-diabetic, could decrease conversion to type 2 diabetes by 57% with the loss of 5 to 7% of body weight. They could also decrease conversion by 30% with the use of the drug metformin. In this case, lifestyle change accompanied by weight loss was twice as powerful as medication.

As there are 25 million Americans with diabetes and approximately 70 million Americans with prediabetes, and those with prediabetes are converting to type 2 diabetes at a rate of 11% per year, this would suggest in 10 years close to 100 million Americans will have diabetes unless something is done about it. As a consequence, the Centers for Disease Control has put together a national diabetes prevention program to teach those at risk how to live a healthy lifestyle, exercise, and lose weight long-term so as to prevent new cases of type 2 diabetes.

The first step in using such a program is to first identify if you have prediabetes. If you are overweight (body mass index greater than 25.0, but less than 30), or obese (BMI over 30), and have a family history of diabetes, you are at risk. BMI = weight in pounds, multiplied by 703, divided by height in inches squared. Such individuals should have their physician obtain a fasting blood sugar and/or a hemoglobin A1c. Hemoglobin A1c is a non-fasting blood test that can give a three-month average blood sugar result. Fasting blood sugar over 100 mg/dl, but less than 126 mg/dl is consistent with prediabetes. Hemoglobin A1c over 5.7 and 6.4 inclusive is also consistent with prediabetes. Women with a history of diabetes during pregnancy, even if blood sugars post-delivery became normal, also are at risk.

Once prediabetes is identified, the National Diabetes Prevention Program may have classes in your area that you can attend. Alternatively, you can work with your primary care physician and a dietitian to help with weight loss and establishing a healthy lifestyle. Even if you are 30 pounds above your ideal body weight, it is not necessary to lose all 30 pounds to prevent diabetes. A 5-foot, 4-inch woman weighing 200 pounds and having a BMI of 34, would need to lose only 5 to 7% of her body weight or 10 to 14 lbs. in order to decrease likelihood of conversion to diabetes by 57%. Of course, those 10 to 14 lbs. would need to be kept off in order to keep diabetes at bay.

Even in the absence of weight loss, two other interventions can help lower blood sugar and prevent progression to diabetes: exercise and the avoidance of sugar and sweet foods and/or foods with high glycemic index. GI refers to the rate that a carbohydrate containing food appears in the blood stream as glucose. Exercise should be a moderate, aerobic exercise such as brisk walking for 30 minutes, five times a week. The complete avoidance of sugar and sweet foods is helpful depending upon the amount of such foods that are consumed with the more consumed at baseline yielding the biggest improvement with cessation. Identifying foods with a higher GI can prove very helpful to further lower risk, once sugar and sweet foods are avoided.

The glycemic index scale is from 0 to 100, with glucose (simple sugar) equal to 100, and low glycemic foods defined as less than 55 on the scale. Foods with a high glycemic index are white bread or a bagel (GI = 74), white rice (GI = 73), and russet potatoes (GI = 78). These high GI foods may cause a spike in blood sugar and predispose you to the development of diabetes. Root vegetables generally have higher GI than leafy vegetables. Sweet fruits, such as bananas and pineapples, have a higher GI than less sweet fruits such as apples, pears, and berries.

In summary, type 2 diabetes mellitus may be prevented. First, those with prediabetes need to be identified from the group of individuals at potential risk. Second, a strategy for reducing the risk of progression to diabetes has to be implemented. The National Diabetes Prevention Program can help to reduce body weight, foster healthy eating, and increase exercise habits. The loss of only 5 to 7% of body weight in an overweight or obese person may reduce conversion to type 2 diabetes by 57%. Additionally, in the absence of weight loss, daily aerobic exercise, the avoidance of sugar and sweet foods, and consuming foods with a glycemic index less than 55 may also be helpful.

In this way, a healthy lifestyle and diet as part of the Non-Medicated Life, may help prevent the development of diabetes more powerfully than medication. Stay tuned for Part Two (August 2018) to learn how a similar approach may help to result in the actual remission of type 2 diabetes. 

Paul E. Lemanski, MD, MS, FACP (plemanski@capcare.com) is a board certified internist at Center for Preventive Medicine at Community Care Physicians in Albany. He is medical director of the Dept. of Community Medicine and Population Health at Community Care Physicians. Paul has a master’s degree in human nutrition, he’s an assistant clinical professor of medicine at Albany Medical College, and a fellow of the American College of Physicians.