Summary of roundtable discussions
By Dr Duane Mellor RD RNutr PhD
Dr Duane Mellor is a double award-winning registered Dietitian, Senior Lecturer at Aston Medical School, Associate Dean Public Engagement at Aston University and member of the British Nutrition Foundation’s Scientific Committee and regularly contributes to MyNutriWeb. Alongside his teaching and research interests, which have focused on supporting people living with diabetes, he is also interested in how health and nutrition messages are communicated by the media (and universities) to the public.
Written in collaboration with the International Sweeteners Association.
Low and no calorie sweeteners (LNCS) always seem to be a controversial topic. This has not been helped by a number of World Health Organisation (WHO) reports over the last year.
These started with the conditional recommendation that LNCS should not be recommended in supporting weight management for people living with obesity. This has been followed up with further recommendations by WHO that aspartame, a type of LNCS is a possible 2B carcinogen following a review by International Agency for Research on Cancer (IARC), which was released at the same time as a report from the Joint Expert Committee on Food Additives (JECFA), which suggested current acceptable daily intake (ADI) recommendations of 40mg/kg/day were still safe.
Put together, these three reports seem confusing, one saying don’t recommend all LNCS, one saying one type of LNCS is a possible carcinogen and the third saying current recommendations on LNCS are still safe. This has clearly added to the public’s level of confusion. Therefore, in September 2023 MyNutriWeb held an expert roundtable to discuss what all this might actually mean for food and nutrition professionals and more importantly the public. The need for this roundtable event was highlighted by a poll of attendees at the start of the event showing an overall lack of confidence with respect to advice about using LNCS, with just 31% of the audience feeling confident about the topic.
“The WHO reports, given how high profile they are, lead to a real plethora of snappy headlines and lots of social media activity saying “Aspartame causes cancer”. However when you really dig into it, that is not what they’re saying at all. I think it has created a lot of concern with the general public.” – Matthew Lambert, Panelist
The roundtable started with a keynote presentation by Professor Katherine Appleton, from Bournemouth University. Professor Appleton shared findings from her recent systematic review and meta-analysis co-authored with colleague Professor Peter Rogers which investigated the effects of LNCS on energy intake and body weight. The presentation covered the difficulties of assessing this as we need to consider the effect of reducing calories by using LNCS instead of sugar in drinks, the effect of sweet taste, and questioned whether sweeteners may behave differently if we cannot taste them. Professor Appleton’s review suggested that by swapping sugar for LNCS, a modest but significant weight reduction of about 1kg can be achieved. However, when investigating the effect of swapping water for LNCS, or if LNCS were taken blinded from taste, they had no effect on weight in randomised controlled trials.
“Low calories sweeteners can be beneficial for weight loss or weight maintenance, plenty of evidence suggests this. There may be a need for more evidence looking at the impacts of low calorie sweeteners on long-term chronic conditions. But weight, of course, plays a role in many of these conditions as well.” – Professor Katherine Appleton, Keynote Speaker
The second keynote presentation was from Food Science Consultant, Dr Rebecca Lopez-Garcia, who discussed the safety aspects of LNCS. With over 25 years’ experience of food safety and toxicology, she discussed the key aspects of assessing the safety of LNCS. Dr Lopez-Garcia discussed the principles of food additive safety, including how acceptable daily intakes (ADI) are calculated. Details of how exposure and the amount or dose of a food additive were considered across the lifespan of person to determine the ADI. It was also highlighted that when looking at LNCS along with all other additives we need to consider how it is absorbed, distributed, metabolised, and excreted so we can consider the biological plausibility of any adverse effects claimed. She shared the knowledge that in normal diets people do not exceed the ADIs of LNCS, and therefore inclusion is very safe. Importantly, a rigorous safety evaluation of food additives, including LNCSs, is carried out by food safety bodies, including JECFA, before these ingredients can be authorised for use in foods and beverages consumed by the public.
“IARC looks at hazard, which is anything that could potentially cause harm, at any level, at any dose. They base their evaluation of aspartame on three cancer studies. It may be associated, but in reality, there’s no direct correlation. It just limited evidence from three studies.
JECFA is the group that actually looks into foods. So they take this hazard information, all the relevant safety science, the good, the bad, and the ugly. They evaluate everything, and then they evaluate the risk, which is the probability of harm actually happening.
So that’s the big difference between the IARC conclusion and the JECFA conclusion. And basically, JECFA is saying, if you consume within the ADI, then the safety is studied and it is safe to consume these compounds. So I don’t think they’re actually opposing views, but it is very difficult for the general public to interpret.” – Dr Rebeca Lopez Garcia, Keynote Speaker
Following the keynote lectures the speakers were joined by Registered Dietitian, Nichola Ludham-Raine, and Matthew Lambert, Health Information and Promotion Manager at World Cancer Research Fund (WCRF) to discuss key questions about the use of LNCS. These included the question “Should sweeteners be recommended to support people with dietary change?” The context often missed in technical guidelines, such as those from WHO, was discussed, and it was concluded by the panel that although directly and alone the effect of LNCS on weight management are minimal, they can be helpful in supporting beneficial changes to an overall dietary pattern. Additionally, the benefits of reducing sugar intake should not be ignored. This view was extended when considering the public concerns about cancer and LNCS. In response to these questions, Matthew Lambert from the WCRF discussed the evidence and position of the WCRF concluding that evidence does not suggest a clear link between LNCS and an increased risk of developing cancer.
“WHO classifying aspartame as a Group 2B carcinogen, is far from saying that aspartame causes cancer. Saying that something is possible is very different from saying something is probably or definitively linked to cancer.”
“There are many factors that affect overall cancer risk in a much, much bigger way than sweeteners ever would. For example, smoking, sun exposure, excess adiposity etc.” – Matthew Lambert, Panelist
So, although WHO suggest that LNCS do not help decrease weight, perhaps that does not mean that they do not have a role in supporting weight management. It is the context of how they fit in the wider dietary intake that matters.
In addition, the evidence which links LNCS to cancer is weak, often lacking in plausible mechanism. It is important when looking at epidemiology, that it needs to make sense from a biological perspective. To reduce risk of cancer, other factors are more important including overall dietary pattern, smoking, sun exposure and if someone is living with obesity.
The concept of taste preference, and driving desire for taste for sweeteners, was also discussed, and it was shared that evidence on this is limited. This is being explored currently, so although there are ideas that if people eat less sugars their taste buds adapt, the evidence is not yet conclusive.
“There is a suggestion, in the Eatwell Guide, that if you reduce your intake of sugars your taste buds will adapt, but we have no evidence for this. Not yet” – Professor Katherine Appleton, Keynote Speaker
The panel concluded that overall dietary patterns were more important than whether or not someone consumes LNCS. Often in studies, they may show reverse causality, in that people who consume more LNCS may happen to consume a less healthy dietary pattern, which can include processed foods.
“Even with the recent publications, no food safety authority around the world changed their approval status of any of the compounds. So these products are safe. The approval process is systematic. It’s continuous. So the authorities are always looking out for additional evidence, but with the current evidence, anything that’s in the market, within the approved limits, is it safe to consume and recommend.” – Dr Rebeca Lopez Garcia, Keynote Speaker
The discussion concluded with the participants responding to the same poll question asked at the start of the event. Results from this showed a 57% swing in confidence in advising individuals about consuming LNCS. Although water is known to be the healthiest drink among all nutrition professionals and many citizens, often people like to have flavour in drinks and enjoy food and drinks. To have pleasure from food, it is important to take a balanced approach. Although simply including LNCS in the diet will not help improve health, they may have a role in a stepwise approach to reducing sugar intake and potentially also intake of sweet foods on a way to achieving a healthier dietary pattern.
“If you like sweet foods it is essentially going to be unrealistic to recommend replacing your sugar-sweetened beverage with water. That’s where low-calorie sweeteners may play a role in maintaining the palatability, or sweet taste of a diet. For some individuals, that will be necessary.” – Professor Katherine Appleton, Keynote Speaker
“We, as health professionals, need to be aware of the evidence base around sweeteners and to be aware of the nuances in the data and just be really clear when communicating to the public. We should be focusing more on what we should be including in our diet, rather than what we shouldn’t!” – Matthew Lambert, Panelist
“Recent reports have not changed the advice that I give and have been giving over the last decade. I believe that they do play a role in weight management, bariatrics, diabetes and reducing the number of fillings that one needs.” – Nichola Ludlam-Raine, Panelist
If you would like to get up to speed on the latest evidence and discussions around low and no calorie sweeteners, the full recording of this roundtable discussion can be found here:
Written in collaboration with the International Sweeteners Association.
Disclaimer: This roundtable event was supported by International Sweeteners Association and World Cancer Research Fund. Approval of each sponsor and activity is carefully assessed for suitability on a case by case basis. Sponsorship does not imply any endorsement of the brand by MyNutriWeb, its organisers, its moderators or any participating healthcare professional, or their association. Sponsorship funds are reinvested into the creation and promotion of professional development opportunities on MyNutriWeb.
- ADI = Acceptable Daily Intake
- EFSA= European Food Safety Authority
- FDA= US Food and Drug Administration
- IARC = International Agency for Research on Cancer
- ISA = International Sweeteners Association
- JECFA = Joint FAO/WHO Expert Committee on Food Additives
- LNCS = Low and no calorie sweeteners
- WHO = World Health Organization
- WCRF = World Cancer Research Fund