Preventing type 2 diabetes

Photo of two men outside after doing exercise (PantherMedia / Diego Cervo)

People who have an increased risk of type 2 diabetes can delay the development of the condition for at least a few years by changing their diet, getting more exercise and losing some weight. It's not clear whether making lifestyle changes can also prevent serious complications such as heart attacks.

High blood sugar often isn't noticeable at first. But over time it can damage the eyes, nerves and kidneys. People who have type 2 diabetes are also more likely to have a heart attack or stroke. Various things can help to prevent these long-term health consequences.

But being diagnosed with diabetes will have an immediate impact because from that point on you are considered to be chronically ill. Doctors will suggest going to patient education classes and you will be given recommendations about lifestyle changes and medication. So another aim of preventive measures is to avoid type 2 diabetes from developing in the first place.

Recommendations for preventing diabetes

 There are a lot of recommendations about how to prevent diabetes. Most of them belong to the following categories:

  • Changes in diet
  • More sports and exercise
  • Medication for losing weight
  • Blood-sugar-lowering drugs

What benefits do weight loss, diet changes and more exercise have?

A number of studies have looked into the effects of these preventive measures. Most of the people in the study were women and men who were over the age of 45 and had a higher risk of developing diabetes. They had risk factors like being overweight or slightly higher blood sugar levels than normal.

Research has shown that changing your diet and getting more exercise can reduce the likelihood of developing diabetes in the next few years.

The study participants aimed to change their diet and eat fewer calories. They had patient education classes to help them achieve this goal. In most of the studies, they were advised to eat fewer saturated fatty acids and get more fruit and vegetables in their diet. They also did about 30 minutes of exercise per day – such as brisk walking, jogging, cycling or swimming. The aim of following this diet and exercise program was to lose about 3 to 6 kilograms.

This is what was found after about four years:

  • Without a lifestyle program: about 26 out of 100 participants were diagnosed with type 2 diabetes.
  • With a lifestyle program: about 15 out of 100 participants received this diagnosis.

In other words, 11 out of 100 men and women were able to avoid developing diabetes by making changes to their diet and getting more exercise.

But it's not clear how many people were able to prevent diabetes over the long term by making these lifestyle changes. The same is true concerning another important issue: whether losing weight and changing these habits can help to prevent long-term health consequences of diabetes. Only a few studies have looked into the effects of lifestyle changes on heart attacks and other complications caused by diabetes. They haven't found a measurable effect so far.

Can blood-sugar-lowering medications protect you from type 2 diabetes?

Changing your eating habits and getting more exercise are some of the first steps that people take to prevent high blood sugar levels. So far, medication hasn't played much of a role in the prevention of diabetes. Many different blood-sugar-lowering medications are used in the treatment of type 2 diabetes, though. Medications are also generally prescribed only after diabetes has been diagnosed. Only a few have been tested for the prevention of diabetes.

Studies in this area have tested metformin, for example, in people with an increased risk of diabetes. They were divided into two treatment groups: One group took metformin, and the other group changed their diet and did more exercise. This is what was found:

  • Taking metformin was about as effective as a change in diet and doing more exercise. A similar number of people in each group developed type 2 diabetes.
  • Metformin reduced the risk of developing type 2 diabetes in people who didn't make any significant lifestyle changes.
  • Metformin did not decrease the risk of developing long-term health problems due to diabetes. But the studies only lasted five years at the most.

Medication for the prevention of diabetes can have side effects, though. Severe side effects are rare, but things like gastrointestinal (stomach and bowel) problems may occur.

How effective are these preventive measures?

 People whose blood sugar levels are higher than normal are generally concerned about their health. But having slightly elevated blood sugar levels doesn't always mean that they will continue to rise and cause type 2 diabetes. In some people, the blood sugar levels go back to normal on their own.

Others can at least delay the development of type 2 diabetes by changing their diet, getting more exercise and keeping an eye on their weight. Doing these things might even prevent diabetes from developing at all. But there's no guarantee here because your metabolism may reach its limits at some point anyway, simply due to older age.

Either way, it's important to not only focus on blood sugar levels. A major aim of prevention is also to avoid long-term consequences of diabetes, such as cardiovascular (heart and blood vessel) disease, at a younger age. The risk of having a heart attack or stroke is also greater if you have high blood pressure or high cholesterol. So it's a good idea to treat those kinds of health problems too.