Expert Opinion: Sugar Tax and Diabetes
In early 2016 the number of individuals diagnosed with diabetes in the UK hit 4 million. Sugar has become the new enemy of good health and is associated with obesity, although the relationship between sugar-sweetened drinks and body weight remains controversial.
A recent analysis of randomised clinical trials showed consumption of sweetened drinks promotes weight gain in both children and adults and is likely to be a contributory factor to the increasing problem of obesity. In susceptible individuals, obesity is a major risk factor for development of Type 2 diabetes which increases risk of cardiovascular disease such as heart attack and stroke. 10% of the NHS budget (£5.5 billion annually) is spent on diabetes monitoring and treatment for the disease itself or it's serious complications including heart and kidney disease, blindness and nerve damage. This is of major concern as the population ages and gets fatter.
What is Type 2 Diabetes and how does the body react?
Type 2 diabetes has been increasing at an exponential rate in the last 20 years, keeping pace with the increases in obesity. Large fat deposits, particularly accumulating around the body organs in the abdomen, produce hormones known as adipokines, which cause insulin resistance, leading to hyperglycaemia and Type 2 diabetes. The body reacts to maintain blood sugar levels in the healthy range (4-8mM) by production of excess insulin, which overcomes the resistance initially, but eventually damage occurs to the cells producing insulin, making the hyperglycaemia worse.
Many obese individuals may be pre-diabetic, where insulin resistance is already present, but overproduction of the hormone keeps blood glucose levels within or just above the healthy range. At this stage, before damage to the insulin producing cells occurs, the effects are reversible and diabetes development can be delayed or prevented. However, once the damage to the cells producing insulin occurs, this is no longer reversible and Type 2 diabetes occurs. At the University of Bradford, our group is interested in the links between insulin resistance and damage to blood vessels. We think its critical to identify how high blood glucose causes damage in the circulation. We believe Type 2 diabetes is only going to increase, making our work vital in trying to reduce heart attacks and stroke.
Sugary drinks
Sugary drinks have no nutritional value and a high glycaemic index, meaning they are quickly absorbed. There is strong evidence this raises blood glucose levels, leading to increased secretion of the hormone insulin into the blood. Insulin promotes glucose uptake from the blood into muscle and adipose tissue cells and we know this is blocked in pre-diabetes when there is resistance to the hormone. Frequent consumption of sugary drinks is thought to damage the insulin producing cells so speeding up Type 2 diabetes and the complications associated with the disease. We believe the recent news story indicating that NHS cafes have decided to introduce a sugar tax does make sense, as a study in Mexico found that taxing sugary beverages did reduce consumption in that population. Reducing unhealthy choices on site in the NHS and should be welcomed, however, it might be just as useful to stop stocking such drinks, therefore removing temptation altogether.
reacting to BBC News story on NHS England and 20% sugar tax