Sugars and Sugar substitutes

Have you ever craved for something sweet?

I know I have on perhaps too many occasions. Sometimes I indulge myself and give in to the craving. But as my mother said, no doubt countless other mothers have said before her, “everything in moderation”.

The following blurb contains general information on Sugars with links to Tables containing specific information of commonly found monosaccharides and disaccharides. I have only included polyols for sugar substitutes as I am not inclined to use artificial sweeteners for baking.  

Glucose is a sugar (saccharide), it is a monosaccharide meaning it contains only one sugar unit. Other monosaccharides are fructose and galactose. We use glucose as an energy source for our bodies - essentially our brain needs glucose to function. Our brain may be only 2% of our body weight but it uses a massive 25% of our body’s daily glucose requirements. There are a number of monosaccharides found in nature but the three main ones normally absorbed during digestion are glucose, fructose and galactose. When two sugar units or monosaccharides are joined together they form a disaccharide. Normal table sugar or sucrose is a disaccharide made up of the monosaccharides glucose and fructose. Lactose is a disaccharide containing glucose and galactose. Oligosaccharides are carbohydrates (sugars) that contain 10 or less sugar units joined together. Larger scale saccharides are called polysaccharides and are made up of a large number of sugar units. The polysaccharides cellulose and starch only contain glucose as the sugar unit. Although we need glucose to function we do not need it in the form of sugar. We may want it - but we don’t need it provided our diet contains sufficient starch or other polysaccharides that can be broken down into monosaccharides. Of course our bodies can also use other energy sources such as fats and proteins, but the brain does require glucose.

A sweet treat every now and then can be a wonderfully pleasurable experience. Apple pie with lashings of cream, honey biscuits, fruity custard tarts the list goes on and on. Unfortunately some people can not digest lactose (lactose intolerant) or have fructose malabsorption or are fructose intolerant. Certain sweet treats (those listed) for this group of people instead of being pleasurable can end up being painful. The lactose and fructose instead of being processed in the small intestine end up being food for bacteria in the large intestine. One of the by-products produced by the bacteria is gas and there can be lots of it. I was lactose intolerant for a number of years and it astounded me how distended my stomach could actually be if I consumed dairy products containing lactose.

Other people may be following a FODMAP diet and avoid foods that contain FODMAPs. FODMAP (http://shepherdworks.com.au/disease-information/low-fodmap-diet) stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. Polyols are also known as sugar alcohols. Polyols are common in no added sugar sweets and usually come with a warning on the packet “Excessive consumption may have a laxative effect”.  If the saccharide or polyol is fermentable it means that they can be food for bacteria in the large intestine. For some individuals this will mean a bout of diarrhoea, flatulence and cramping.

Table 1 (Monosaccharides) and Table 2 (Disaccharides) contain a list of sugars by name (refined and unrefined) and their saccharide component. To compare the different sugars I have included the energy (kJoules/100g), the amount of sugar they contain and where possible their glycemic index (GI) value. The GI value is an estimation of how much the available carbohydrate in a food will raise a person’s blood glucose level, relative to eating pure glucose. For more information on the GI and Glycemic loads (GL) of particular foods visit the University of Sydney glycemic index website.

http://www.glycemicindex.com/

There are many reasons you may want to use a specific sugar. Some of these may be due to;

Diet (ie. intolerance to a specific sugar) - Rice malt syrup, glucose

Sustainability - Coconut Palm sugar (unrefined), Organic Palm sugar (unrefined)

Refining process - Icing sugar, Rapadura sugar, Molasses sugar

Flavour – Maple syrup, muscovado sugar, molasses, Concentrated apple juice, Honey

Liquid vs solid - Golden syrup vs brown sugar

Low GI - Fructose

There has been a lot of concern regarding fructose, in particular how it is metabolised in our bodies and where it ends up. The following is a quote from Professor Jennie Brand-Miller and Dr Alan Barclay.

“The evidence to-date suggest that consuming moderately high (>50 but <100g, or 12 – 24 teaspoons) amounts of pure refined fructose may have an adverse effect on postprandial triglycerides and that consuming large amounts (>100g, or 24 teaspoons) on top of a regular food and beverage intake will contribute to weight gain and fasting triglyceridaemia. The reality is that few humans eat pure refined fructose, let alone in the amounts required to cause adverse health problems. People should continue to be advised to eat added sugars, including fructose, in moderation. “

For more detailed information visit

http://www.theaustralianparadox.com.au/index.php

One can of softdrink can contain 41 g of sugar (sucrose)! 

A good film to watch is "That Sugar Film" - it certainly highlights the problems a high sugar diet can have on the body.

 

Highly refined sugars (solid) are pure carbohydrate and essentially have no other nutrients in them. In Table 1 and Table 2 these are the sugars that have an energy value of 1700 kJ/100g (Some sources put the energy value of pure sugar as 1620 kJ/100g). Refined sugars in liquid form will have a lower energy value due to the water used to dissolve them, for example glucose syrup. Less refined or unrefined sugars will have lower carbohydrate content per 100g and a correspondingly lower energy value. The lower carbohydrate content is due to the presence of water and traces of other nutrients that are in the product. An indication of whether a sugar is refined is the presence of crystals. The coconut palm sugar (pictured below) is unrefined whereas the sugar and molasses sugar are not. 

That brings us to polyols. These are commonly found in "sugar free" or "no added sugar" sweets. As mentioned previously they can cause gastric distress however as they generally have a lower GI than sucrose and are labelled "sugar free" they are seen to be a good alternative to sugar, particularly for diabetics. But, and there is a big but, they are not devoid of kilojoules. Furthermore they generally do not have the same level of sweetness as sucrose (levels can be found in polyols) and you need to use more to get something to be as sweet. For example 100 g of sorbitol contains 1400 kJ. The same amount of sucrose contains 1700 kJ. In this case there is more energy in the 100 g of sucrose. However to make the product have the same level of sweetness you need to use nearly 2x as much sorbitol. In the end it will be 1700 kJ (sucrose) or a bit less than 2800 kJ (sorbitol). Erythritol (used in Norbu & Natvia) is approximately 70% as sweet as sucrose but only has 100 kJ/100 g. Furthermore it has a really low GI and is less likely to cause gastric distress.

Ultimately it is up to you the type of sweetener you use. Unrefined sugars may contain additional beneficial nutrients however the level of them is relatively small. These nutrients tend to be more concentrated in black strap molasses. Dates or date sugar have the added benefit of fibre.