This article was published in the August/September edition of NHD Magazine. There are a lot of scare-mongering messages about this topic, so I found it interesting to take a close look at the evidence related to sweeteners and health.

There can be a lot of confusion about the role and safety of sweeteners.

This article will explore the evidence related to artificial sweeteners and bulk sweeteners.

The term ‘sweeteners’ will be used to encompass both types of sweetener during this article.

Background:

Sugars (also called ‘nutritive sweeteners’ or ‘caloric sweeteners’) such as sucrose and fructose contain carbohydrates and provide 3.75 calories per·gram¹. Nutritive sweeteners are found in: table sugar, honey and syrups.

Artificial sweeteners are used to provide sweetness while containing little to no calories¹.

These are used in a variety of products such as: diet soft drinks, jellies, yoghurts, desserts, chewing gum, sweets and table top sweeteners². Artificial sweeteners can also be referred to as: sugar substitutes, non-nutritive sweeteners, intense sweeteners and high-potency sweeteners¹.

Polyols like sorbitol, xylitol and mannitol are sugar alcohols (also called ‘bulk sweeteners) which are technically nutritive sweeteners, but they are lower in sugar and calories than other sugars (2.4 calories per gram)¹.

The sweeteners listed in table one and two are licensed for use in the UK; each has a corresponding E-Number, which means that it has passed the safety tests for approved use in the EU and the UK³.

Table One^1-4,6,8-11

Table Two^3-5

Artificial sweeteners range from 30 times sweeter than table sugar (or ‘sucrose’), to 37,000 times sweeter.

Whereas bulk sweeteners often have the same level of sweetness as sucrose; but can also be up to 50% less sweet. Therefore bulk sweeteners are used as fillers to improve the consistency of products, as well as their role as sweeteners⁴.

As part of the safety evaluation process by the European Food Safety Authority (EFSA), artificial sweeteners are given an acceptable daily intake (ADI) value. This ADI, which applies to all food additives, is an estimate of the amount that is considered to be safe to consume everyday over a lifetime. It is measured as milligrams per kilogram of body weight per day⁵. For example, aspartame has an ADI of 40mg per kg body weight per day.

To reach the ADI for aspartame, a 70kg adult would have to consume over 5 litres of Diet Coke everyday over a lifetime^1,6.

Rather than allocating an ADI, bulk sweeteners which are licensed for use in the EU are classified as ‘‘acceptable’’, which means that the expected exposure to these is considered to be safe⁴.

An excess intake of bulk sweeteners is not advised as this can cause gastrointestinal issues such as: cramping, bloating, flatulence and diarrhoea6.

Dental Health:

There is an EFSA approved health claim that replacing sugar with intense sweeteners (i.e. artificial sweeteners) certain sugar alcohols (xylitol, sorbitol, mannitol, maltitol, lactitol, isomalt and erythritol), and other nutritive sweeteners (D-tagatose, isomaltulose and polydextrose) is good for dental health². This is because these sweeteners don’t ferment and cause demineralisation of teeth.

These sweeteners can actually help to maintain tooth mineralisation.

Diabetes:

Using artificial sweeteners in place of sugary options can be a useful strategy for managing blood glucose levels for some people with Diabetes.

This can also be useful for those with reactive hypoglycemia^1,12

There is some evidence that saccharin and sucralose may increase insulin levels, but overall the research is conflicting so more well designed human studies are needed to investigate this^13-16.

EFSA approved the health claim that replacing sugar with the same sweeteners outlined above (i.e. artificial sweeteners, xylitol, sorbitol, mannitol, maltitol, lactitol, isomalt, erythritol, D-tagatose, isomaltulose and polydextrose) reduces the increase in blood sugars which occurs after a meal². However, EFSA could find no clear relationship between using artificial sweeteners to replace sugar, and maintaining normal blood sugar levels overall².

For those who carb count it is not clear how bulk sweeteners should be counted, as the carbohydrate levels absorbed from these can vary¹⁷. Bulk sweeteners are also used in products which are labelled as ‘diabetic food’, however these products are not recommended as they can still be high in fat and calories and may cause gastrointestinal problems if consumed in large amounts¹⁷.

Weight Management:

Although swapping sugars for sweeteners reduces calorie intake, there are concerns that sweeteners may interfere with our metabolism and increase our appetite^1,18. Some studies have found that using artificial sweeteners as part of a weight loss program can help participants to improve weight loss^1,19-22 and a review by EFSA in 2011 found no clear relationship between using sweeteners and weight management². A recent systematic review by Azad et al. found evidence from cohort studies that consuming artificial sweeteners was associated with a slight increase in BMI, weight and waist circumference; but there was no association found from randomised-controlled trials²³. There is a small amount of research that suggests that those who consume sweeteners may have a lower overall diet quality, this may also play a role in terms of weight management²⁴. There is limited information about the effect of polyols on weight management²⁵.

Furthermore, it has been found that sweeteners can alter gut bacteria which may be harmful. This has mainly been found in animal studies and the results of human studies have been mixed^{26- 28}. Other studies have found that changes in our gut bacteria can be been linked to our weight and overall health^29-30, so it is possible that sweeteners may promote weight gain via changes to our gut bacteria, but more human trials are needed to test this.

Overall, more research is needed to clarify the role that sweeteners play in weight management.

The BDA acknowledges this, but also highlights that sweeteners can be helpful in some cases as they “allow patients and (or) clients to alter their calorie intake without making significant dietary changes”¹.

Cancer:

Some studies in the 80s and 90s found an association between between aspartame, saccharin and cancer development in rats.

However, more recent large studies which were carried out in humans provide strong evidence that artificial sweeteners do not increase cancer risk^6,31.

As discussed above, both of these sweeteners have undergone rigorous evaluation by EFSA and are licensed as safe to use in the EU within their respective ADI levels^1,6.

Phenylketonuria (PKU):

This rare genetic condition is a deficiency of the the enzyme phenylalanine hydroxylase, which means that the amino acid phenylalanine cannot be metabolized and can build up to dangerous levels if not carefully excluded from the diet.

Aspartame contains phenylalanine

Therefoire, it is a legal requirement in the UK to clearly label that a food product ‘contains a source of phenylalanine’ if it contains aspartame^1,32.

Pregnancy:

ADI levels are very conservative as they are calculated at one hundredth of the amount that is safe to consume.

Sweeteners are considered safe to use during pregnancy, as long as consumption remains below the ADI.

However low calorie options shouldn’t replace nourishing options during pregnancy; for example diet pop shouldn’t replace milky drinks¹.

Infants & Young Children:

In the EU artificial sweeteners are not allowed to be used in any food which is designed for infants or young children (up to three years old), including baby food^1,33. An important reason for this is because infants and children have high energy needs to support growth and development^1,33. There is also a lack of safety data in relation to the use of artificial sweeteners in this age group^1,33-35.

A recent study found that breastfeeding mothers who drank diet drinks which contained sucralose and acesulfame-potassium resulted in these sweeteners transferring to their breastmilk³⁶. However, this was a small study and more research is needed to investigate whether this might have any negative health effects for a baby consuming this breastmilk.

Conclusion:

The evidence base shows that artificial sweeteners and bulk sweeteners are safe for the general public to consume, including pregnant women (up to the advised ADI in the case of artificial sweeteners). However artificial sweeteners are not recommended for infants, children under three years old, and people with PKU need to avoid aspartame. There is no strong evidence that sweeteners increase the risk of cancer in humans; but there is good evidence that they are good for our teeth and can help to manage blood sugar levels. Sweeteners can also be useful as part of weight management interventions, especially for those with a sweet tooth.

Overall, sweeteners can be used as part of dietetic interventions, but as with most aspects of nutrition this should be assessed on a case-by-case basis.

References:

1. The British Dietetic Association (BDA 2016) “Policy Statement The Use of Artificial Sweeteners”. Available at: https://www.bda.uk.com/improvinghealth/healthprofessionals/sweetners
2. European Food Safety Authority (EFSA 2011) “Scientific opinion on the substantiation of health claims related to intense sweeteners and contribution to the maintenance or achievement of a normal body weight (ID 1136, 1444, 4299), reduction of post-prandial glycaemic responses (ID 4298), maintenance of normal blood glucose concentrations (ID 1221, 4298), and maintenance of tooth mineralisation by decreasing tooth demineralisation (ID 1134, 1167, 1283) pursuant to Article 13(1) of Regulation (EC) No 1924/2006”. Available at: https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2011.2229
3. FSA “EU Approved Additives or E numbers” [accessed April 2018 via: https://www.food.gov.uk/business-guidance/eu-approved-additives-and-e-numbers]  
4. Mortensen et al. (2006) “Sweeteners permitted in the European Union: Safety aspects”. Available via: https://www.researchgate.net/publication/239599910_Sweeteners_permitted_in_the_European_Union_Safety_aspects
5. European Food Safety Authority (EFSA) Glossary [accessed April 2018 via: https://www.efsa.europa.eu/en/glossary-taxonomy-terms]
6. European Food Safety Authority (EFSA) “Aspartame” [Accessed April 2018 via:  http://www.efsa.europa.eu/en/topics/topic/aspartame]
7. Storey et al. (2007) “Gastrointestinal tolerance of erythritol and xylitol ingested in a liquid”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/16988647
8. European Food Safety Authority (EFSA 2016) “Safety of the proposed extension of use of acesulfame K (E950) in foods for special medical purposes in young children” [accessed April 2018 via: https://www.efsa.europa.eu/en/efsajournal/pub/4437]
9. European Food Safety Authority (EFSA 2016) “Scientific Opinion on the safety of the extension of use of thaumatin (E957)” [accessed April 2018 via: https://www.efsa.europa.eu/en/efsajournal/pub/4290]
10. International Sweeteners Association “Asparatme-Acesulfame Salt Factsheet” [accessed April 2018 via: https://www.sweeteners.org/assets/uploads/articles/files/Aspartame-Acesulfame-Salt-Fact%20Sheet_Aug09.pdf]
11. International Sweeteners Association “Neotame Factsheet” [accessed April 2018 via: https://www.sweeteners.org/assets/uploads/articles/files/Neotame-Fact-Sheet_Jan10.pdf]
12. Tandel (2011) “Sugar substitutes: Health controversy over perceived benefits”. Journal of Pharmacology and Pharmacotherapeutics 2, 236-243.
13. Just et al. (2008) “Cephalic phase insulin release in healthy humans after taste stimulation?”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/18556090
14. Teff et al. (1995) “Sweet taste: effect on cephalic phase insulin release in men”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/7652029
15. Pepino et al. (2013) “Sucralose affects glycemic and hormonal responses to an oral glucose load”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23633524
16. Ma et al, (2009) “Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/19221011
17. Diabetes UK “Sugar, sweeteners and diabetes” [accessed April 2018 via: https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/carbohydrates-and-diabetes/sugar-sweeteners-and-diabetes]
18. Yang (2010) “Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings”. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2892765/
19. Mattes and Popkin (2009) “Nonnutritive sweetener consumption in humans: effects on appetite and food intake and their putative mechanisms”. The American Journal of Clinical Nutrition 89, 1–14.
20. Kanders et al. (1988) “An evaluation of the effect of aspartame on weight loss”. Appetite. Available at: https://www.ncbi.nlm.nih.gov/pubmed/3190220
21. Blackburn et al. (1997). “The effect of aspartame as part of a multidisciplinary weight-control program on short- and long-term control of body weight”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/9022524
22. Rolls et al. (1991) “Effects of intense sweeteners on hunger, food intake, and body weight: a review”. Available at:  https://www.ncbi.nlm.nih.gov/pubmed/2008866
23. Azad et al. (2017) “Non-nutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies”. Available at: http://www.cmaj.ca/content/189/28/E929.long
24. Piernas at al. (2015) “A dynamic panel model of the associations of sweetened beverage purchases with dietary quality and food purchasing patterns”. American Journal of Epidemiology 181, 661–671.
25. Gardner et al. (2012) “Nonnutritive sweeteners: current use and health perspectives: a scientific statement from the American Heart Association and the American Diabetes Association”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22778165
26. Suez et al. (2014) “Artificial sweeteners induce glucose intolerance by altering the gut microbiota”. Available via: https://www.ncbi.nlm.nih.gov/pubmed/25231862
27. Palmnas et al. (2014) “Low-dose aspartame consumption differentially affects gut microbiota-host metabolic interactions in the diet-induced obese rat”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25313461
28. Suez et al. (2015) “Non-caloric artificial sweeteners and the microbiome: findings and challenges“. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25831243
29. Halmos & Suba (2016) “[Physiological patterns of intestinal microbiota. The role of dysbacteriosis in obesity, insulin resistance, diabetes and metabolic syndrome]“. Available at: https://www.ncbi.nlm.nih.gov/pubmed/26708682
30. Turnbaugh et al. (2009) “A core gut microbiome in obese and lean twins”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/19043404/
31. Cancer Research UK “Food Controversies – Artificial Sweeteners” [Accessed April 2018 via: http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/diet-and-cancer/food-controversies#food_controversies1]
32. European Commission Directive (2008). “Laying down specific purity criteria concerning sweeteners for use in foodstuffs” Available at: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32008L0060:EN:NOT
33. Europa (2012) “Summaries of EU legislation. Authorized sweeteners”. Available at: http://europa.eu/legislation_summaries/other/l21069_en.htm
34. Food Standards Agency (2014) “Food Additives Legislation Guidance to Compliance”.
35. European Food Safety Authority (EFSA) “Sweeteners” [accessed April 2018 via:  http://www.efsa.europa.eu/en/topics/topic/sweeteners]
36. Rother et al. (2018) “Pharmacokinetics of Sucralose and Acesulfame-Potassium in Breast Milk Following Ingestion of Diet Soda”. Available at: https://www.ncbi.nlm.nih.gov/pubmed/?term=Pharmacokinetics+of+Sucralose+and+Acesulfame-Potassium+in+Breast+Milk+Following+Ingestion+of+Diet+Soda