Reducing Glycaemic Response With Inulin

Tuesday, September 12th, 2017

Carbohydrates are an essential food in our daily diets. More studies are now supporting the importance of reduced glycaemic response and the use of inulin and oligofructose can help achieve that as well as other health benefits. By Diederick Meyer, scientific and regulatory affairs, Sensus


Carbohydrates are an essential food within our daily diets and are recommended by the European Food Safety Authority (EFSA) and World Health Organization to provide for 40-55 percent of our total energy intake.

There are various types of carbohydrate structures which will determine rapid absorption with high blood glucose levels such as simple sugars, or alternatively, fermentation of certain polysaccharides by our healthy intestinal microbiota with minimal impact on blood glucose.

The increasing pace of today’s lifestyles with eating on-the-go and reduced physical activity tends to encourage snacks and foods comprising rapidly digestible sweet carbohydrates or fats with high calories besides high blood glucose levels.

Increasing studies support the importance of a reduced glycaemic response within our diet contributing, amongst others, to potentially lower the incidence of type 2 diabetes.

The food industry can now satisfy consumer need by developing products that reduce glycaemic load and with lower sugar content also reducing the caloric intake, that taste as good as the original foods.

Health Impact Of A Low Glycaemic Diet

Lowering the postprandial glycaemic response can be beneficial for a wide range of consumer groups with impaired glucose tolerance or type 2 diabetes.

Chronically high levels of blood glucose can damage proteins, decreasing their functionality, as well as increasing inflammation which has a detrimental effect on organs such as the kidneys, retina and blood vessels. Despite controversy, recent meta-analysis continues to support the view that glycaemic load may be an important dietary feature relevant to the incidence of diabetes.

The impact of diabetes in both the US and Europe is significant both in terms of human suffering as well as massive health care costs. It is predicted that one in 10 people will have diabetes in 2035. Moreover, there is a substantial increase in type 2 diabetes especially in children.

Twenty years ago, only one percent of diabetes cases in children were type 2, whereas now it has risen to 50 percent. The increase in obesity both in the US and in Europe is driving a growing epidemic in type 2 diabetes. Obesity is connected with an increase in insulin resistance, the first step in developing type 2 diabetes.

Food manufacturers can use functional ingredients such as inulin and oligofructose from chicory roots to develop products that support healthy blood glucose levels.

With an authorised health claim for a lowered glycaemic response at hand, manufacturers can now market inulin/oligofructose-containing products not only with nutrition claims (lower sugar content and perhaps higher fibre content) but also with a health claim.

Food manufacturers that go a step beyond merely replacing sugar with inulin and oligofructose can furthermore claim lower caloric content.

Glycaemic Response

Each time we consume food that contains starch and sugars, these ingredients are broken down during digestion into simple sugars, such as glucose and fructose.

These sugars are then transported via the blood stream to all organs and tissues, which convert these sugars into energy. The uptake of glucose in our blood stream causes the blood glucose level to rise. This rise in blood glucose after a meal is the so-called postprandial glycaemic response.

The increase in glucose levels of the blood leads to another physiological response, the secretion of the hormone insulin from the pancreas.

This hormone conveys a signal to our organs, such as our muscles, to take up the glucose from the blood, which leads to a lowering of the blood glucose level. In fact, this is a well-designed control and steering mechanism of our metabolism. The rise and fall in blood glucose levels is known as glycaemic response.

Not all foods trigger the same glycaemic response in terms of the level and duration of the glucose peak. High glycaemic response foods spark a fast steep peak, followed by a fast decrease. In contrast, low glycaemic response foods lead to a lower and slower increase in blood glucose levels, and therefore a lower peak, with a slow decrease.

Whether a product is categorised as high or low glycaemic response depends on the type of carbohydrates that is ingested.

Some suggest that when glucose levels get below the starting level— which is the glucose level before food is ingested—people experience increased hunger feelings and start snacking.

When we sustain high glucose levels and in turn high insulin levels for a prolonged period of time, organs respond less to insulin. In other words, they will become resistant to insulin.

As a result, when the same amount of insulin is excreted, less glucose will be taken up from the blood and glucose levels in the blood remain high. More insulin is then secreted to lower the glucose level, but this cannot go on forever.

Our cells will become insensitive towards the insulin stimulus, meaning that insulin resistance could rise. Over time, the pancreas can potentially produce less of the hormone. This may lead to the unhealthy situation of type 2 diabetes, also known as ‘non-insulin dependent diabetes’ (in people with type 1 diabetes, the cells that produce insulin are damaged due to a genetic defect).

Lowering Glucose Fluctuations

Carbohydrates that are not broken down or digested into simple sugars by the upper human digestive tract will not affect the blood glucose level.

Inulin and oligofructose are such types of carbohydrates which instead reach the large intestinal tract where they are fermented by the gut microbiota. This means that their building blocks (mainly fructose) are not released into our blood stream (as opposed to sugar, which is digested into glucose and fructose that is then released into the blood stream).

As a result, they do not affect the blood glucose level and trigger a minimal glycaemic response. In essence, a diet with low glycaemic response foods will result in lower fluctuations in blood glucose levels.

Fortunately, both inulin and oligofructose are high-fibre carbohydrates well suited for replacing sugar in a range of food products. By using these ingredients in food products, food manufacturers can lower the glycaemic response of the food.

Both oligofructose and inulin make a good sugar substitute, especially to replace the bulking proper ties of sugar. That said, oligofructose has a sweeter taste than inulin. However, the final taste and texture of the product with inulin or oligofructose will not be that different compared to the ‘full-sugar’ product, but the product will cause a lower postprandial glycaemic response.

An additional benefit is that the use of oligofructose or inulin increases the amount of dietary fibre, helping consumers increase their fibre intake. This is a welcome added benefit of using these ingredients as the intake of fibre is well below the recommended rates nearly everywhere in the world.

Glycaemic Load Reduction

Sucrose, glucose syrup and other sugars are used in a wide range of food applications because of their functional properties. For example, they add sweetness, function as a bulking agent, improve mouth feel, and they can be used for crystallisation, or to improve shelf life of the final product by decreasing water activity, thereby reducing microbial growth.

The perception of sweetness in food products is affected by a combination of the sweetness level and the sweetness profile. For the latter, this means how quickly the sweetness appears, the intensity of the peak and how long the sweetness lasts until it disappears.

Although inulin and oligofructose are sweet, they are around 30 to 50 percent as sweet as sucrose. Generally, consumers do not notice a relative change in sweetness of 5-10 percent.

However, this depends on the type of application, for example, liquid versus solid foods, along with the fat content of the food product. To compensate for lower sweetness levels in a sugar-reduced formulation, food manufacturers can combine inulin or oligofructose with a high-intensity sweetener, such as sucralose or steviol glycosides.

This combination also helps to reduce the undesired off- and/ or aftertaste associated with most high-intensity sweeteners. In fact, by using a combination of a high- intensity sweetener with inulin or oligofructose, food manufacturers can also optimise the taste profile of their food products.

Moreover, research shows that inulin and oligofructose have valuable synergy with high-intensity sweeteners. This means that the combination of inulin or oligofructose with a high-intensity sweetener results in even more sweetness than summing the sweetness of inulin and the high-intensity sweeteners.

The texturising and sensor y proper ties of inulin make this ingredient an excellent sugar replacer in a wide range of foods segments.

EFSA has given a positive opinion for a lower glycaemic response health claim for inulin and oligofructose from chicory roots which will come into effect in the near future. Food manufacturers can use these functional ingredients to develop food products that support healthy blood glucose levels.

Furthermore, with the various sweetening and texturising properties of inulin and oligofructose, healthier food products with reduced sugar content can be manufactured. Inulin and oligofructose in combination with high-intensity sweeteners can be used to produce great-tasting food products with a lower or even zero sugar content.