Prediabetes is a condition in which blood sugar levels are higher than normal, but not high enough to be classified as full-blown diabetes. According to studies from a number of universities and national surveys, 37 percent of adults in the United States have prediabetes and 12 percent to 14 percent have diabetes, indicating that about half of adults in this country are affected by high blood sugar. Most cases of prediabetes are not diagnosed, meaning people don’t know they have it.
There are two types of diabetes. Type 1, which often comes on in childhood, is an autoimmune disease and is not discussed in this column. In type 2 diabetes, people demonstrate a fasting plasma glucose level of 126 mg/dL or higher on two occasions. If you have a blood glucose level of 200 at random times—not after fasting for eight hours—you may also have diabetes. Another test commonly used is known as hemoglobin A1c and indicates blood sugar levels in the recent past. Levels of 6.5 or higher are seen in diabetes; levels of 5.7 to 6.4 may indicate prediabetes, and levels below 5.7 are normal.
Readers probably already know that diabetes is an unpleasant and dangerous disease, affecting vision and the brain, heart, nervous system, kidneys and feet. Medication, exercise and a careful diet can reverse it, but it is better to prevent it.
Prevention programs are widespread and generally consist of emphasizing weight loss (loosing even 5 percent to 7 percent of present body weight is very helpful), exercise (such as walking or other activities that raise your heart rate) and a healthy diet. Walk about 30 minutes almost every day. There is widespread agreement that diets to prevent diabetes decrease or eliminate drinks with added sugar and replace red meat with beans, nuts, poultry, fish and yogurt. Yogurt, rather than other sources of dairy foods, seems to reduce the risk of diabetes. To facilitate weight loss, cheese should be used sparingly, just as a condiment. Foods containing refined starches, sugars and white potatoes should be avoided.
In a Harvard study by Walter Willett, an esteemed professor of nutrition at Harvard and the Harvard School of Public Health, coffee and decaffeinated coffee decreased the risk of diabetes. That’s good news for coffee lovers, but avoid adding sugar! Stevia seems to be a safe sweetener. Foods that contain magnesium, such as leafy greens, beans, nuts and whole grains, also decreased the risk. Following this diet carefully will naturally lead to weight loss in most people.
Willett has some encouraging words about lifestyle changes to prevent diabetes. “If you make a change in your diet or lifestyle today, you’re taking your foot off the accelerator, and this happens almost overnight. If you exercise today, your insulin resistance goes down within hours. And if you keep up the daily exercise, within a day or two your risk of diabetes drops. Changing your diet might take longer to make a difference, but it’s a matter of weeks, not years. Even if you are right at the brink of diabetes, you can still rapidly reduce your risk.”
Sadja Greenwood lives in Bolinas.