Natural vs. artificial sugars

Thanks to Emily Briggs, final year medical student at the University of Birmingham, for putting this piece together. See Emily’s previous piece on cervical smear testing here.

Table top sugar has a pretty bad reputation these days. We are plagued with natural alternatives to get our sweet tooth fix with the promise that they are ‘healthy’ and ‘natural’. But is the organic honey/coconut/agave/date syrup really worth the faff (and price!) for a sweet cuppa over the white stuff our ancestors have used for decades?

Let’s look at an example: one medium sized banana vs a small packet of Haribo. Both roughly 100 calories, virtually 0g fat or protein and 30g carbohydrates (1). So, surely they produce exactly the same effect on your body?

If you control calories or carbohydrates for weight management then according to the rules of your diet these two foods are technically equivalent. They should, in theory, produce roughly the same metabolic effect on your body as they both contain roughly the same sugar content. This is the basis for the ‘If It Fits Your Macros’ or IIFYM diet, as it is known in the fitness industry, whereby you consume foods based on a strict ‘macronutrient’ plan made up of defined amounts of carbohydrate, protein and sugar (2). The selling point of this diet is that the source of the macronutrient fuel is flexible – you could consume your carbohydrate ‘allowance’ from acai berries or Percy Pigs and it should, supposedly, have the same effect on weight loss.

However, this method of dieting is based on very black and white metabolic science and takes no account of the other forms of nutrition food provides us with. Food is not just an energy source, but also a source of vitamins, antioxidants, fibre and a stimulant of powerful hormones for satiety, glucose, fat and protein metabolism and cellular repair. Furthermore, health is not solely defined by weight and body fat percentage. There is so, SO much more to it than that. And hopefully you would not have found yourself reading this blog if you didn’t already know that! So let’s look at the debate in more detail – starting with the basics…

What is sugar?

Ultimately, whatever the source, all sugars are simple carbohydrates that are broken down in the body for energy in roughly the same way. The ‘digested’ form of these sugars is usually one of three molecules: glucose, fructose or, more rarely, galactose. These molecules are made up of the same gross structure, a carbon based ring, and belong to a family called the ‘monosaccharides’ which describes the fact that they are single carbohydrate molecules. These single molecules can be linked together in long chains to form more complex carbohydrates called polysaccharides such as starch. Once digested, these sugars reach the bloodstream and are taken up into cells where they enter a series of metabolic pathways that produce energy for your body to function, broadly described by the term ‘respiration’:

Glucose + Oxygen → ATP (energy) + Carbon Dioxide + Water

Longer chain, complex carbohydrates take a little bit more digesting to reach the bloodstream and  our cells but ultimately end up in the same pathway as those simple sugars. This leads on to the first argument for consumption of natural sugars over artificial sugars: glycaemic index.

Glycaemic index

Glycaemic index represents the rise in blood sugar a food produces. The higher the GI of a food the more quickly it reaches the bloodstream, and the more of a spike in blood sugar is produced (3). This can also affect hunger levels – high GI foods give you a ‘sugar rush’ and can leave you feeling hungry and sluggish (the effects of hypoglycaemia, or low blood sugar) pretty soon after you’ve eaten them. Low GI foods keep us fuller for longer and our blood sugars more stable. The benefits of this, other than for weight management and dieting, are better glycaemic control and stable insulin levels which is of paramount importance in preventing or managing the development of type 2 diabetes (4).

However, foods with a higher fat content are also digested more slowly and hence have a lower glycaemic index. This means that some lower GI options may actually be less ‘healthy’ than their higher GI counterparts and it is important to weigh up all of the nutritional variables when choosing options for a balanced diet.

Generally speaking, although not always, natural sugars are of a lower glycaemic index compared to those that are artificially produced. This is illustrated quite well by the Haribo vs banana debate. As well as containing simple sugars such as fructose and glucose, an banana also contains fibre and long-chain starchy carbohydrates which slows down its digestion and thus it is considered an  ‘average GI’ food (6). The exact glycaemic load will depend on how ripe your banana is – the more ripe, the sweeter the banana and the higher its GI. You can eat a banana (one that is not overly ripe!) at the beginning of an exam and it should keep your brain fed with glucose for some time. Haribo, on the other hand, contains virtually nothing other than glucose and a teeny bit of protein from the gelatine used to form the sweets. Thus, Haribo sweetie sugar shoots straight to the bloodstream following consumption and leads to a sharp rise in blood sugars. Within 30 minutes or so insulin is released into the bloodstream and your blood sugars should be back down to normal, and you’ll be hungry and distracted again (5). This is not ideal for pre-exam nutrition, unless you feed yourself Haribo every twenty minutes (I have friends who have been known to do this!).

However, Haribo and other foods containing fast-release sugars are extremely useful in certain situations – for example, when your blood sugar is too low (for reference of this, see memes of Slovak cyclist and World Champion Peter Sagan fisting Gummy bears into his mouth shortly after completing a 200 km ride) (7).

So clearly, there is a place for artificial sugar when it is needed. But in general, everyday consumption of sugar from natural sources is better for your health. Or is it? Let’s turn our attention to fructose…

Fructose

Fructose is the main sugar contained in fruit and ‘natural sweeteners’ derived from fruits and trees such as carob syrup, maple syrup and agave syrup. Recently some studies have shown that excessive consumption may lead to insulin resistance and obesity – a disease known as ‘metabolic syndrome’ that can progress to full-blown Type 2 diabetes mellitus, high blood pressure and obesity (8). This is because, although very similar to glucose in structure, fructose is only metabolised in the liver and is more lipogenic, or fat-producing, than glucose. Thus, fructose is thought to behave more like fats than other types of carbohydrate.

However, in 2016 the European Food Safety Authority refuted this and pronounced fructose to be preferable over sucrose and glucose as a simple sugar due to its decreased effect on post-prandial blood sugar levels – and thus a lower glycaemic index (9). So the jury is out on fructose as of yet, and I wouldn’t stop eating fruit as part of your diet based on a few small studies. Ultimately, as we already know, the most important recommendation to live by is that of ‘portion control’ and limiting the amount of energy you get from sugar in your diet. It would impact your health if you ate an excessive amount of bananas or Haribo or both – a rule which can be (with some tiny exceptions) applied to most foods!

Honey

Another naturally sweet product, honey has long been thought of to have antibacterial properties – I am sure many will share my memories of gulping down (and wincing at) honey and lemon water when you were sick with a sore throat. Honey can contain a number of substances including hydrogen peroxide that have an antibacterial effect and, in theory, could aid in fighting against an infection (10). Unfortunately, since honey is a totally natural product, the concentrations of antibacterial compounds in honey varies greatly between different honeys.

Manuka honey is considered the most potent in its health benefits and is often sold in health food shops and marketed as ‘medicinal’ (11). There is actually no compelling evidence for or against the use of honey in lieu of drug treatment of infections but a Cochrane review did find it to be preferable over ‘no treatment’ of acute cough in children (11). It must be cautioned, however, that honey is not suitable for children under the age of 12 months as it may contain spores of bacteria that can cause a frightening but thankfully rare disease called infant botulism.

Whether or not you agree with this evidence, it is important to be aware of the differences between sources of honey. The best honey you can use comes from your local beekeeper. As well as natural antibacterial properties, there is some weak evidence that local honey has been found to be beneficial for hay-fever sufferers, with the theory that it provides gradual exposure to local pollen that can allow your body to build up immunity (13).

Furthermore, supporting local beekeepers is really important to protect the bee colonies as they are more likely to follow sustainable and ethical honey-producing methods. In case you haven’t already been made aware by David Attenborough, bee populations are declining because of modern agricultural methods and climate change, and without them humans will not be able to survive on our planet for very long (14). Supporting local colonies is one way of doing your bit to help avoid their extinction – a slight digression from our topic of sugar and health – but important nonetheless!

‘Natural alternatives’ to the sugar cube

So you’ve decided you want to switch up the sugar in your chosen hot brew for something more natural. But what are the options? Be warned that some are less ‘natural’ than they claim to be…

• Coconut sugar: This has a low glycaemic index and can be used as a direct substitute for sugar in tea, coffee and recipes. Although it is rich in certain minerals, the amount of sugar you would have to consume to reap the benefits would exceed your daily sugar allowance so it is not advised take the marketing health halo of this substance as gospel. Coconut sugar tends to be a bit more expensive than other natural sugar substitutes so isn’t accessible for all of us.
• Honey: The GI of honey varies greatly depending on how much processing it has undergone – i.e. the more natural and unrefined the honey is the lower GI. Some commercially produced honeys can even contain added sugar. As mentioned previously, it may have antibacterial properties and so may be helpful for those recovering from an infection. The most potent antibacterial action comes from Manuka honey – which is classified according to its ‘Unique Manuka Factor’ or UMF.
• Maple syrup: This is a natural substance that is formed from extracting the sap of the maple tree. It is considered to have a relatively low glycaemic index and many people also opt for this over honey as it is vegan and widely available.
• Agave syrup: Also known as agave nectar, this is made by extracting the sap of the agave plant. It consists mainly of fructose and therefore has a lower GI. It is also sweeter per gram than sugar meaning that you can use less agave syrup than you would sugar, and thus consume fewer calories. Agave syrup is debated in the same way as fructose, and some experts believe that excessive consumption can be harmful and contribute to development of metabolic syndrome.
• Date syrup: This is a fairly unrefined sweet substance extracted from dates using a soaking and squeezing process. Some nutrients within dates and fibre may be retained in the syrup however this depends on the extraction process. Like agave, date syrup is also high in fructose and the same concerns apply to its nutritional status. We recommend just eating the whole date so you’re getting both the sweet stuff but also the fibre.

A word on ‘sugar-free’ sweeteners

The sweetener vs sugar debate is an issue that deserves a whole article to itself but I could not have written this without at least mentioning it. Substances such as aspartame and acesulfame K have been demonised for a number of years with some bodies claiming that safety testing performed on these substances has been limited and their use may be linked to cancer, thyroid disease and disease in pregnancy (15). However, there is not enough evidence to support this as of yet and the European Food Safety Authority (EFSA) has declared them safe for consumption at present (16).

Furthermore, the proportions that have shown links to the development of disease are in extreme excess – so it is very unlikely drinking a can of Diet Coke a day is going to hurt. Sweeteners can in fact be a really useful alternative for those who need to limit consumption of sugar and also in the prevention of tooth decay.

As with anything, it is advised to consume them in moderation to avoid any adverse side effects. For example, excessive consumption of certain types of sweeteners can lead to diarrhoea and flatulence – a price I’m not sure you would be willing to pay in exchange for the extra calories!

There has also been some concern over the metabolic response to sweeteners, despite their calorie-free status. As of yet studies have provided fairly conflicting and insignificant evidence and responses may depend on long term changes to gut bacteria that would require a consistently high consumption of sweeteners (17, 18, 19, 20). On the whole, sweetener consumption is a controversial and debated topic that clearly needs a great deal more attention to provide a conclusive answer.

So whether it be Haribo, a fruit salad or a ‘sugar-free’ artificially-sweetened treat, there is no right or wrong answer to this nutritional debate. There is, however, a unanimous agreement that moderation is key when it comes to your intake of sugar, whatever the source, as overdosing on sweet stuff can lead to serious health issues later on down the line.

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References

(1) My Fitness Pal. Calorie Calculator [Internet]. 2018 [cited 2018 Jun 20]. Available from: https://www.myfitnesspal.com/

(2) If It Fits Your Macros. Diet Plan [Internet]. 2018 [cited 2018 Jun 20]. Available from: https://www.iifym.com/

(3) Diabetes UK. What is Glycaemic Index? [Internet]. 2017 [cited 2018 Jun 20]. Available from: https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/carbohydrates-and-diabetes/glycaemic-index-and-diabetes

(4) Wang Q, Xia W, Zhao Z, Zhang H. Effects comparison between low glycemic index diets and high glycemic index diets on HbA1c and fructosamine for patients with diabetes: A systematic review and meta-analysis. Prim Care Diabetes. Elsevier; 2015 Oct 1;9(5):362–9.

(5) Freckmann G, Hagenlocher S, Baumstark A, Jendrike N, Gillen RC, Rössner K, et al. Continuous glucose profiles in healthy subjects under everyday life conditions and after different meals. J diabetes Sci Technol. 2007;1(5):695–703.

(6) Harvard Health Publishing [Internet]. 2018 [cited 2018 Jun 17]. Available from: https://www.health.harvard.edu/diseases-and-conditions/glycemic-index-and-glycemic-load-for-100-foods

(7) Cycling Weekly. Peter Sagan’s post-race recovery food: gummy bears [Internet]. [cited 2018 Jun 20]. Available from: https://cycling.today/peter-sagans-post-race-recovery-food-gummy-bears/

(8) Bantle JP. Dietary Fructose and Metabolic Syndrome and Diabetes. J Nutr. 2009;139(6):1263S–1268S.

(9) Panel E, Nda A. Scientific Opinion on the substantiation of health claims related to fructose and reduction of post-prandial glycaemic responses. 2011;9(1924):1–15.

(10) Kwakman PHS, Zaat SAJ. Antibacterial components of honey. IUBMB Life. 2012;64(1):48–55.

(11) Majtan J, Klaudiny J, Bohova J, Kohutova L, Dzurova M, Sediva M, et al. Methylglyoxal-induced modifications of significant honeybee proteinous components in manuka honey: Possible therapeutic implications. Fitoterapia. Elsevier; 2012 Jun 1;83(4):671–7.

(12) Oduwole O, Udoh EE, Oyo-Ita A, Meremikwu MM. Honey for acute cough in children. Cochrane Database Syst Rev. 2018;2018(4).

(13) Saarinen K, Jantunen J HT. Birch Pollen Honey for Birch Pollen Allergy – A Randomized Controlled Pilot Study. Int Arch Allergy Immunol. 2011;155:160–6.

(14) BBC. Supersocieties: Bee dynasty. United Kingdom; 2014.

(15) Centre for Science in the Public Interest. Chemical Cuisine [Internet]. [cited 2018 Jun 20]. Available from: https://cspinet.org/eating-healthy/chemical-cuisine#acesulfamek

(16) European Food Safety Authority. Sweeteners [Internet]. 2018 [cited 2018 Jun 20]. Available from: http://www.efsa.europa.eu/en/topics/topic/sweeteners

(17) Pepino MY et al. Sucralose affects glycaemic and hormonal response to an oral glucose load. Diabetes Care. 2013 Sep;36(9):2530-5.

(18) Ma J et al. Effects of article of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects. Am J Physiol Gastrointest Liver Physiol. 2009 Apr;296(4):G735-9. doi: 10.1152/ajpgi.90708.2008.

(19) Carlson HE et al. Aspartame and its constituent amino acids: effects on prolactin, cortisol, growth hormone, insulin, and glucose in normal humans. Am J Clin Nutr. 1989 Mar;49(3):427-32.

(20) Anton SD et al. Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels. Appetite. 2010 Aug;55(1):37-43. doi: 10.1016/j.appet.2010.03.009. Epub 2010 Mar 18.