Type 2 diabetes (also known as non-insulin dependent diabetes mellitus) occurs when the pancreas either doesn’t make enough insulin or the body becomes resistant to insulin, resulting in abnormally high blood sugar levels.
Complications of diabetes include a higher risk of heart attack or stroke, eye disease, kidney disease, erection problems and nerve damage, which may result in traumatic injury and infection, possibly leading to limb amputation.
Aboriginal and Torres Strait Islander people who are over 35 years old are at higher risk of type 2 diabetes than most non-indigenous Australians, such as Australians of European descent. While the exact figures aren’t known, it’s estimated that the prevalence of type 2 diabetes in Aboriginal people is at least 2-4 times (and may be as much as 10 times in some communities) that of non-indigenous Australians.
And not only is type 2 diabetes more common, but it also begins at an earlier age in Aboriginal people than in other Australian populations, which means that the risk of developing complications from diabetes also occurs at a younger age.
In addition, the Aboriginal and Torres Strait Islander death rate from diabetes is believed to be up to 17 times that of non-indigenous Australians, mainly due to high levels of cardiovascular disease (heart and blood vessel problems) and kidney disease.
Why are Aboriginal Australians at risk?
Doctors believe that a combination of a genetic predisposition and an unhealthy lifestyle contributes to the high rates of type 2 diabetes in indigenous Australians.
Research suggests that the metabolism of Aboriginal Australians has been geared towards making them efficient hunter-gatherers, which was vital for a successful traditional lifestyle.
Aboriginal Australians have a lighter build than European Australians, with relatively long legs, short bodies, narrow chests and narrow hips and shoulders.
When Aboriginal people lived a traditional lifestyle, they generally had a low body mass index (BMI, which is determined by your weight in kg divided by your height in metres squared), compared with what’s considered normal for European Australians, and their weight did not tend to increase with age.
This naturally light body type and low BMI of Aboriginal Australians indicates that their bodies may need less energy (food) to sustain them than European Australians.
It’s also thought that Aboriginal people had a highly efficient metabolism which helped them survive while living a traditional lifestyle. For example, some Aboriginal and Torres Strait Islander populations have mild glucose intolerance and relatively high cholesterol, characteristics that would help them gain weight to keep them alive when necessary.
While they lived traditionally and were fit and active, and ate high-fibre, low-fat meals such as wild animals, vegetables and fish, they were protected from becoming obese or developing diabetes.
This idea is backed up by a study that has shown that a group of Aboriginal people who live traditionally in Arnhemland in the Northern Territory, who have very low body mass indexes (BMIs) and are fit and active, seem to show no indications that they are at high risk of heart disease or diabetes. And there’s no other evidence to show that Aboriginal people had diabetes, or other conditions affected by lifestyle such as heart and blood vessel disease, obesity or high blood pressure, when they lived a traditional lifestyle.
Now, with fewer Aboriginal people living a traditional lifestyle, and more being exposed to today’s Westernised lifestyle, with foods rich in fat and sugar, alcohol, cigarette smoking and a sedentary lifestyle, their once-efficient metabolism may now be acting against them. The genetic make-up that enabled Aboriginal people to survive when food was scarce may now be a big disadvantage, promoting weight increases, diabetes, and associated conditions such as high blood pressure and heart disease. Research has shown that Aboriginal people who live a Westernised lifestyle have high rates of obesity, impaired glucose tolerance, high blood pressure, high levels of triglycerides (fats) in the blood, and excessively high insulin levels in the blood.
What can be done?
For Aboriginal and Torres Strait Islander people, treatment of type 2 diabetes is the same as that for other people with the condition: lifestyle modification, monitoring blood glucose and, if necessary, tablets to help keep blood sugar under control (oral hypoglycaemic medications) or, in some cases, insulin injections.
Of course, the successful prevention and management of diabetes in Aboriginal and Torres Strait Islander communities encompasses a wider picture, in which economic and social factors and political intervention all play a part.
However, given that a Westernised lifestyle is a big contributor to the development of type 2 diabetes, evidence has shown that adopting the beneficial aspects of the traditional lifestyle can help improve the health of people with diabetes, and could help prevent the development of diabetes in those at risk.
For example, one study of 10 Aboriginal people who had diabetes and 4 who did not have diabetes showed that after several weeks of living a traditional lifestyle (with regular physical activity and low-fat, high-fibre meals) certain diabetes-related metabolic abnormalities had improved. For example, people in the study showed normal levels of triglycerides (a type of fat) in the blood, as well as improved levels of fasting glucose, glucose tolerance and insulin secretion.
While it’s not practical for many people to adopt a traditional Aboriginal lifestyle, the principles remain true for all of us, whether we’re from an indigenous or non-indigenous background: adopt a low-fat, high-fibre eating plan, ensure you are physically active, and maintain a healthy weight to help improve metabolic control.