The WHO has issued a new guideline advising against the use of non-sugar sweeteners (NSS) for weight control and reducing the risk of non-communicable diseases in adults. Read more about the latest guideline in this article.

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Recently, the World Health Organisation (WHO) published a new guideline on non-sugar sweeteners (NSS), which recommends against the use of NSS to control body weight or reduce the risk of non-communicable diseases (NCDs) such as type 2 diabetes, cardiovascular diseases, and mortality in adults.

The recommendation applies to both artificial sweeteners (such as aspartame, saccharin, sucralose etc.) and plant-based ones (such as stevia), but not sugar alcohols (such as sorbitol, xylitol etc.)

The discussions among various stakeholders (experts, promoters of NSS, researchers, regulatory agencies among others) in India show whether or how we have to implement this guideline appropriately.

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WHO commissioned review

"NSS include synthetically derived chemicals and natural extracts that may or may not be chemically modified. Because of their ability to impart sweet taste without calories, some argue that they can help to prevent overweight and obesity. However, others suggest that they may increase risk. From an oral health standpoint, NSS might reduce the risk of dental caries if used as a replacement for sugar. Although commercially available NSS are tested for toxicity before being introduced into the market, potential long-term effects on the health of consuming NSS at levels below the acceptable daily intake (ADI) established by authoritative bodies are not as well characterised."

Health effects of the use of non-sugar sweeteners: a systematic review and meta-analysis (2022"), a WHO-commissioned study cautioned.

The review cautioned that there may be potential undesirable effects from long-term use of NSS; these include an increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults.

"Replacing free sugars with NSS does not help with weight control in the long term. People need to consider other ways to reduce free sugars intakes, such as consuming food with naturally occurring sugars, like fruit, or unsweetened food and beverages.”

-Francesco Branca, WHO Director for Nutrition and Food Safety said in a press release

"NSS are not essential dietary factors and have no nutritional value. People should reduce the sweetness of the diet altogether, starting early in life, to improve their health." Francesco Branca clarified

The WHO rated the recommendation as conditional because the link observed in the evidence between NSS and disease outcomes might be confounded by baseline characteristics of study participants and complicated patterns of NSS use.

"The decisions based on this recommendation may require substantive discussion in specific country contexts, linked for example to the extent of consumption in different age groups," the agency cautioned.

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The evidence

1. The evidence from the recent systematic review and meta-analyses of randomised controlled trials (RCTs) and prospective observational studies found that higher NSS consumption by adults led to lower body weight and body mass index (BMI), compared with not consuming NSS or consuming lower amounts of NSS when assessed in short-term RCTs; however, it was associated with increased BMI and risk of incident obesity in long-term prospective observational studies.
2. Long-term NSS use was associated with increased risk of type 2 diabetes, cardiovascular diseases (CVDs) and mortality in prospective cohort studies conducted in adults. However, significant effects were not observed on intermediate markers of disease such as fasting glucose, fasting insulin or blood lipids when assessed in short-term RCTs.
3. Studies conducted in children and pregnant women were more limited than those identified for adults. One RCT conducted in children reported a reduction in several measures of body fatness when sugar-sweetened beverages were replaced with beverages containing NSS; however, no effect was observed when results for BMI score were combined with those from a second trial.
4. Results from prospective observational studies did not suggest any significant associations between NSS use and measures of body fatness. Two RCTs conducted in children reported lower indicators of dental caries with the use of the NSS stevia. All other identified studies reported no significant associations between NSS use and prioritised health outcomes in children.

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The study

The systematic review of RCTs and observational studies that assessed the health effects of NSS use in adults, children and pregnant women identified 283 unique studies, including 50 RCTs, 97 prospective cohort studies and 47 case-control studies.

Only studies in which NSS were consumed in amounts within the Acceptable Daily Intake (ADI) either because this was explicitly stated in the study or it was reasonably inferred that the ADI was not being exceeded, were included in the systematic review. Because assessing the effects of NSS use in individuals with diabetes was beyond the scope of this guideline, studies specifically assessing the effects on individuals with pre-existing diabetes or including only such individuals were not included in the review.

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Expert comments 

Professor Nita Forouhi, MRC Epidemiology Unit, University of Cambridge

According to Professor Nita Forouhi, the findings of the WHO report are justifiable for general populations of people without diabetes, based on the inclusion of all eligible evidence from multiple research study designs, but are limited by several factors, many of which the report itself acknowledged.

"Notably, the WHO recommendation on avoiding the use of non-sugar sweeteners for longer-term weight management or chronic disease prevention is conditional, therefore context and country-specific policy decisions may be needed rather than necessarily being universally implemented as they stand. The role of non-sugar sweeteners as a way to reduce calories in the short-term is, however, supported by evidence – so using sweeteners can be part of interventions to manage weight in the short term," she suggested in a press release from the Science Media Centre, London.

Professor Forouhi found that while researchers explicitly assessed the risk for bias and quality of the studies included in the review by using established frameworks, overall, most studies, including RCTs, were of low or very low certainty, with only a few of moderate or higher certainty. She described many key limitations of the study.

According to Professor Rita Forouhi, the WHO's extensive review adds meaning to the scientific understanding of the relationship between NSS consumption and multiple indicators of human health. The key takeaway is that for longer-term weight management and for chronic health conditions such as the development of future type 2 diabetes and cardiovascular disease, the use of NSS is not advisable.

Professor Tom Sanders, Professor Emeritus of Nutrition and Dietetics, King’s College London

“What the review does not consider is the impact of replacing sugar-sweetened drinks with artificially sweetened drinks. There are high-quality randomised controlled trials that show that when artificially sweetened drinks covertly replace sugar-sweetened drinks in children they help prevent unhealthy weight gain. In my opinion, this advice, which is based mainly on a null effect of artificial sweeteners on weight gain, is likely to cause a lot of confusion in the public health arena because the sugar levy in the UK has drinks manufacturers replacing some or all of the sugar with artificial sweeteners,” he clarified.

Reaction from International Sweeteners Association (ISA)

In a swift reaction, published with predictable alacrity, on 15 May 2023, the day WHO published its new guideline, ISA issued a critique titled "The WHO guideline on use of non-sugar sweeteners risks hindering global efforts to stem the rise of non-communicable diseases (NCDs)".

"It is not based on a strong evidence base or supported by the evidence presented in the WHO systematic review that was commissioned with the aim to inform the guideline. It is only a conditional, or else weak, recommendation for which WHO is uncertain about the desirable or undesirable effects of its implementation, for example, if the guideline risks leading to increased sugars intake and associated health outcomes." the ISA warned.

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Conflicting views among doctors and other experts in India

"The World Health Organisation's warning against the use of artificial sweeteners to control body weight or reduce the risk of non-communicable diseases has been dubbed "exaggerated" and "alarmist" by senior doctors and dieticians across the country. The guidelines are not supported by sufficient scientific data for a public health warning" (The Times of India, May 18, 2023).

Food Safety and Standards Authority of India (FSSAI) has set up a panel to review the issue.

“WHO guidelines on non-sugar sweeteners must be incorporated in our programmes” (ANI, May 17, 2023) Dr VK Paul, NITI Ayog health member said.

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FICCI seminar

The press release carried the views of some of the leading experts in the field. According to Dr B Sesikeran, Former Director, of the National Institute of Nutrition, ICMR Hyderabad, the risk of consuming sugar is much higher than the minimal risk associated with sweeteners, with limited data from India. He pleaded for further research and data generation to manage risks effectively.

"The alarming rise in type-II diabetes and the staggering number of individuals with pre-diabetes necessitates urgent action and awareness. There is a need to advocate for the use of non-nutritive sweeteners, approved by global regulatory bodies, to provide sweetness without compromising the management of diabetes," Dr Rajeev Chawla, Senior Diabetologist and Director, North Delhi Diabetes Centre, New Delhi clarified.

“Prediabetes, Insulin resistance is striking sub-clinically across young adults today both in overweight and lean obese. It is evident that the key determinants are total empty calories and the quality of food in the diet. Priming the taste buds to get acquainted with less sweet tastes right from childhood is crucial. While following a healthy diet, these sugar swaps with sweeteners can be a stepping stone, which can help in reducing the added sugar intake.” Dr Jagmeet Madan, Principal, Professor, Director (Research and Consultancy), Sir Vithal Das Thackersey College of Home Science (Autonomous), SNDTWU, Mumbai, National President, Indian Dietetic Association added.

Dr Mangesh Tiwaskar, Consultant Physician and Diabetologist, Shilpa Medical Research Centre, Mumbai noted that sweeteners can promote diet healthfulness by increasing the palatability of nutrient foods and beverages.

"NNS consumption may be a marker for other positive health behaviours and lifestyles. As far as the BMI is concerned, all the non-nutritional sweeteners are either weight neutral or sometimes help you to sustain lost weight. Evidence reveals that the use of NNS influences the microbial composition of the oral mucosa," he added.

Mr Tarun Arora, President of, the FICCI Centre for Nutrition Excellence noted that the WHO guidelines say that substantive discussions are required and country-specific policy is required. In his opinion, the discussion among the experts in India clearly indicates that the status quo on sweeteners is to be maintained and long-term studies in the country are required.

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Need for more India-based research

Addressing the FICCI Seminar, Dr Pulkit Mathur, Professor and Head, Dept. of Food and Nutrition and Food Technology, Lady Irwin College, University of Delhi, Delhi stated that we need more data to understand the consumption of NNS and their effect on health. He pleaded for carrying out studies of well-defined design "with larger sample size, more homogenous samples, monitoring the overall diet espcially mapping the total energy intake".

"We have just completed a study on replacing added sugar in daily tea/ coffee/ milk with sweetener to understand its effect on health and we are presenting the results before American Diabetes Association (ADA). This is one of the largest randomised clinical studies on sweeteners, done so far in India.”

-Dr V Mohan, Chennai-based diabetologist revealed

Since then, Dr. V Mohan and other researchers made two poster presentations at the 83rd Scientific Sessions of the American Diabetes Association at San Diago, California (23-26 June 2023)-

1) ADA 614-P: Effect of Non-nutritive Sweetener Sucralose on Cardio-metabolic Risk Factors among Overweight and Obese Adults in India—A Randomised Clinical Trial

2) ADA 615-P: Effect of Nonnutritive Sweetener Sucralose on Cardiometabolic Risk Factors among Adults with Type 2 Diabetes in India—A Randomised Clinical Trial

While reviewing the new WHO guideline on non-sugar sweeteners, Prof Nita Forouhi, MRC Epidemiology Unit, University of Cambridge, pointed out that the duration of most of the Randomised Control Trials (RCTs) was very short, mostly a couple of weeks or under 3 months, while very few were longer than six months; of around 50 RCTs, only five were of one year or longer duration.

The studies by Dr V Mohan and co-authors also were very brief (12 weeks); however, they are a good beginning. They must extend the studies with a well-defined study design, "With larger sample size, more homogenous samples, monitoring the overall diet esp. mapping the total energy intake.", the requirements Dr.Pulkit Mathur proposed for such studies.

The Central Government must support the efforts financially. NITI Ayog, FSSAI and other independent agencies must play their roles. An independent group of specialists should monitor the project. A diabetic nation can ill afford to wait too long to get answers to the vexing questions in managing the disease.

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Uncertainties and other issues

1. So long as the uncertainties of the long-term effect of NNS are not quantified, it is unwise to encourage the young to swap sugar with sweeteners, as proposed by Dr Jagmeet Madan. Better methods of persuasion to avoid excess sugar are called for. Parents must take control, of the way they ensure that their ward completes his/her daily homework!
2. Experts who appreciate the influences of the microbial composition of the oral mucosa must also look at more recent studies such as the randomised controlled trial encompassing 120 healthy adults published in the journal cell on 19 August 2022 which showed that collectively, human NNS consumption may induce person-specific, micro biome-dependent glycemic alterations, necessitating future assessment of clinical implications.
3. The researchers showed that non-nutritive sweeteners (NNS), commonly integrated into the human diet are not inert.

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We need not lose sleep on the impact of NSS

For the present, we need not lose sleep on the impact of NSS, if we understand how regulatory bodies such as the Food and Drug Administration(FDA) arrive at and enforce Acceptable Daily Intake (ADI) of food additives.

Based on detailed reviews and analysis, FDA proposes an ADI of 5mg/kg body weight for Sucralose. As per this standard, a 60 kg person can safely consume 300 mg of Sucralose every day. Since a packet of Sucralose contains 12 mg of the sweetener, at the rate of one packet per cup, a 60 kg person can drink 25 cups of Sucralose sweetened coffee or tea every day. This sweetening for coffee/tea is adequate as Sucralose is 600 times sweeter than sugar. (12 mg Sucralose = 7.2 gm of sugar). These are considering short-term effects.

WHO found that long-term use of NSS has undesirable effects and as such long-term use may be avoided.

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FDA versus WHO

Question: Some organisations, for example, the Food and Drug Administration in the US, have declared over the years that these non-sugar sweeteners are safe for use. If those organisations feel they are safe, then why is the WHO recommending that they not be?

Dr Francesco Branca, The Director, of the Department of Nutrition and Food Safety, WHO Geneva answered this question in a Podcast hosted at the Food Policy Center at Duke University, Sanford on 28 June 2023 (Link to the podcast is included in the reference list)

Francesco: In a sense, it is a different issue. Before any of these compounds are used in food, it has to go through this safety assessment. You mentioned the Food and Drug Administration. FAO and WHO are managing a joint expert committee on food additives that is providing advice to the Codex Alimentarius. And all these bodies, basically what they are saying is, they look at the toxicology of the products and they use animal studies.

In some cases, they look at human studies. But they are basically looking at acceptable daily intakes that provide usually short-term impacts. We are also encouraging these bodies to consider longer-term epidemiological studies to look at other kinds of effects.

For example, at the moment there is a big debate going on because both the International Agency for Research on Cancer and the JECFA,* are looking at the safety of aspartame and considering, for example, certain longer-term epidemiological human studies. These bodies are talking about certain aspects of safety and looking at the very high levels of intake. Just to give you an example, at the moment the acceptable daily intake for aspartame is about 40 milligrams per kilogram per day, which is 2.8 grams for an average individual.

That is about what you would get from 14 cans of a commonly consumed drink. That is a lot. We are saying maybe that is something that can be moderated. So these bodies talk about safe or maximal levels of intake of individual sweeteners. Here, in our recommendation, we are saying this practice of replacing sweeteners with sugars is not going to lead you to improved health gains, but you’re getting into an area of risk that even if it is within the agreed safety level, is something that you may want to avoid.

[*The Joint FAO/WHO Expert Committee on Food Additives (JECFA)]

Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

Dr K S Parthasarathy is a former Secretary of the Atomic Energy Regulatory Board and is a medical physicist with specialisation in radiation safety and regulatory matters.