With the global number of diabetes cases on the rise, including an estimated two million Australians at high risk and many others with silent, undiagnosed type 2 diabetes, it is more important than ever that we focus on ways to prevent or delay diabetes progression.
A healthy diet and active lifestyle are important components in managing diabetes, but is there such thing as an ‘ideal’ diet for someone with type 2? Anyone who has ever tried sticking to a strict diet knows how confusing it can be to understand what will work for them and how difficult it can be to maintain changes in the long term.
The situation is no different for people with type 2 diabetes. Research has revealed new insight, however, into the effectiveness of several popular dietary interventions. These studies suggest that reducing carbohydrate intake in favour of unsaturated fat and protein, increasing your intake of soluble fibre and consistently choosing low-GI foods, along with exercise, will help slow diabetes progression and improve your HbA1c, the marker of blood glucose control.
1. Should you ditch carbs?
Carbohydrates are painted as villains in several well-known diets, such as the Atkins and South Beach Diet and researchers have also explored the impact of eliminating carbs for those with type 2 diabetes. One study, which involved strictly controlled meals for people with Type 2 diabetes, found that reducing the intake of carbohydrates and replacing partly with fat, partly with protein improved glucose control and resulted in a drop in HbA1c.
While eliminating all carbohydrates, as in the Atkins diet, can result in weight loss, a reduction in HbA1c and potentially decrease the amount of medication needed, it is important to consider the diet’s impact on cholesterol levels and its potential to increase the risk of heart disease. And what happens in the real world where a strict low-carb diet is extremely difficult to maintain?
A separate study found that when you offer people advice about lowering their carb intake, you get a completely different result. Glucose levels were a bit lower but the HbA1c the fasting glucose and the LDL (cholesterol) levels were unchanged.
2. Should you head to the Med?
What about the popular Mediterranean diet? Much has been said about the benefits of this diet in preventing diabetes, heart disease, and Alzheimer’s disease. Researchers have found that if you replace carbohydrates with monounsaturated fat, a major component of the Mediterranean diet, you can see a reduction in liver fat as well as a small drop in HbA1C.
This suggests that if you are going to reduce carbohydrates in favour of something else, unsaturated fat and protein should take priority over the saturated fat that is often found in the Atkins diet.
3. What does new research say?
Some of the most exciting research has focused on manipulating the way the stomach empties and the way the pancreas releases insulin in order to better manage type 2 diabetes. Studies have found that a large dose whey protein can slow down the gastric emptying process and prime the pancreas to release insulin, which improves glucose control.
The problem, however, was that it was not feasible to consume the required amount of protein ahead of every meal. Other options, including amino acids and fibres, such as pectin and guar, achieved a similar result but are expensive and un-tasty solutions.
However, Australian researchers, working with Melbourne-based Omniblend Innovation have found a way to deliver a smaller dose of protein and a bit of guar in the form of a palatable pre-meal drink called GlucoControl. This drink will prove especially important in preventing and delaying the progression of type 2 diabetes for those with pre-diabetes or well-controlled diabetes. It lowers the glycaemic index of meals by up to 38% and offers a much simpler and effective way to lower GI when compared with strict diets.
4. So what’s the verdict?
There is not one diet or exercise regimen that will work for everyone, but working with your doctor to develop a comprehensive approach will help slow diabetes progression, even for those who are not yet diagnosed.
Studies from Finland and the US have found that modest weight loss and exercise, an increase in fibre and polyunsaturated fat and less saturated fat can together, produce a dramatic reduction in type 2 diabetes, even more than a decade later. While there is no ‘magic diet’ for type 2 diabetes, we can use what we are learning from these studies to develop effective and more sustainable solutions.
Peter Clifton is an endocrinologist and Professor of Nutrition at the University of South Australia. Professor Clifton has held prestigious posts at CSIRO and at Baker IDI Heart and Diabetes Institute and was a founder and important architect of the CSIRO ‘Total Wellbeing Diet’.