The effect of sweeteners on our health

We don’t realize that many foods and drinks we consume every day have added sweeteners. We should understand the impact of these substances on our metabolism and on our general health.  

The World Health Organization (WHO) recommends that sugar intake should only represent 5% of a person’s daily energy consumption, i.e. no more than 25 grams per day. Given this limitation on sugar intake, the consumption of sweeteners has exploded in recent years. However, according to recent studies, the consumption of sweeteners may not be as beneficial to health as previously thought, as they have been associated with metabolic disturbances.

Tania Mesa – Director of Neolife’s Nutrition and Nursing Unit

Alejandro Monzó- Neolife Nutrition and Nursing Unit

More research is needed to offer compelling data on their long-term effects

The term sweetener refers to food additives that are capable of mimicking the sweet effect of sugar and generally contribute less energy. Some of these are natural sweeteners, while others are synthetic and are known as artificial sweeteners (1). As far as their global classification (table 1), sweeteners can be classified according to their caloric content, their origin or even their chemical structure.

Sucrose (table sugar) has been associated with obesity, type 2 diabetes, cavities and cardiovascular disease, among other illnesses. For decades, health experts have recommended reducing their consumption to prevent these diseases (1.2). However, the elimination of sugar has given way to a long list of sweeteners, which are potentially sweeter than sucrose and barely contribute calories.

The current success of sweeteners is based on contributing lower calorie content to the diet in order to help lower body weight and prevent the development of diseases associated with sugar intake such as diabetes and tooth decay (1). However, more and more doubts are arising among sweetener consumers regarding the benefits and risks associated with their consumption.

It is important to clarify that certain sweeteners that are called natural are not so. The reality is that by the time they reach the supermarket they have undergone multiple chemical processes, meaning they can no longer be considered natural products (2).

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Table 1. Classification of sweeteners, adapted (1).

The vast majority of natural sweeteners have the same caloric value as sugar and honey, but there are also some with no caloric value like Stevia. They are called natural precisely because they come from natural sources in plants or synthesized by animals (as is the case of bees and honey).

Stevia is a plant native to Paraguay used as a sweetener and medicinal plant. Its leaves are much sweeter than sugar and are calorie-free. Several studies show that it can improve insulin sensitivity, reduces glucose levels and also helps lower blood pressure. Stevia is a valid option, but experts warn that it should be consumed in its natural form, such as fresh or dried leaves, since the Stevia-based sweeteners we find in the supermarket combine steviol glycosides and other substances such as erythritol (a sugar alcohol), offering barely any benefits (3).

The controversy over the safety of artificial sweeteners has been increasing for some time. The dramatic rise in obesity has caused consumption of these synthetic sweeteners to soar in recent decades. The most commonly used are saccharin, sucralose, aspartame and cyclamate, but we must ask ourselves: are they safe for our health?

Saccharin is a sweetener authorized by the EFSA (European Food Safety Authority), and we can find it identified as E-954. Saccharin is not metabolized; it is absorbed as is and is quickly eliminated through the kidney without contributing a single calorie. Its admissible daily intake is 5 mg per kg body weight, but it is not an entirely harmless sweetener (4.5).

In the case of cyclamate, identified with the code E-952, its absorption is quite limited, and the little that is absorbed is eliminated undisturbed through urine. Its consumption is currently prohibited in the United States and in various South American countries (4). The problem is that cyclamate becomes cyclohexylamine, a potentially toxic metabolite, interfering in the synthesis of thyroid hormones and potentially producing allergies. The WHO discourages cyclamate in pregnant women and children due to its possible carcinogenic effect and mutagenic effects, limiting the maximum dose to 11 mg per kg of body weight (6).

The use of sucralose, identified with the code E-955, is fairly widespread in the food industry and thus found in a wide variety of processed foods. It is barely absorbed in the digestive tract, and the little that is absorbed is eliminated by urine through the kidneys (4). A study published in the Journal of Toxicology and Environmental Health related to sucralose found that it can reduce the amount of “good” intestinal bacteria, increase the level of pH in the intestine and cause symptoms such as allergies, migraines, gastrointestinal problems, weight gain and higher blood sugar levels. In Europe, the maximum daily dose admitted is 15 mg per kg of body weight (7).

Aspartame, identified with code E-951, is an artificial sweetener made from aspartic acid. Recently, the European Food Safety Authority (EFSA) revised its authorization, concluding that its consumption is safe, though the maximum daily dose is 40 mg per kg of body weight (4). Aspartame is present in numerous processed foods.

A report submitted by the WHO published in the British Medical Journal (9) reveals that there is insufficient evidence to definitively assess the benefits and detrimental effects of sweeteners, in particular the possible long-term effects. In their conclusions, the authors point out that there is no evidence that sugar-free sweeteners are not much better than sugar.

Although sweeteners represent a “useful” resource for many people who do not want to gain weight, the truth is that there is no conclusive evidence that non-caloric sweeteners reduce excess body weight and obesity. Moreover, another study contains evidence that they are not effective for weight loss and can even increase appetite and weight gain (2), contributing to metabolic syndrome and the obesity epidemic (10). The participants in this study, who tried to save kilocalories by taking sweeteners, compensated them later with other more caloric foods, believing that the simple fact of reducing “sugar” meant they could eat foods that turned out to be more caloric in the general calculation. Therefore, it is possible that there is an imbalance in the human brain’s rewards signals related to the feeling of “sweetness” that causes confusion and prevents us from detecting the energy content of foods (2.9).

All artificial sweeteners approved for use have been determined to be safe within acceptable consumption levels. However, currently the western eating pattern is becoming more and more popular, and its base is comprised of ultra-processed foods and products with large amounts of artificial sweeteners. Therefore, it is difficult to estimate the amount of intake. Existing evidence on the benefits of using artificial sweeteners as part of the population’s regular diet is lacking. Future research should focus on new natural sweeteners, identifying the long-term metabolic effects.

We have a duty to properly inform our sense of taste from a young age to avoid masking the real flavors of food with substances we will become dependent on over the years. The healthiest choice is not to trick our brain with reward signals derived from the pleasure we get from eating sweet things, but to balance our diet and sweeten it only when strictly necessary.

Here at Neolife, we recommend avoiding foods that contain sugar in their composition as well as those that include sugar substitutes. If you do consume some kind of sweetener, always prioritize natural ones, as in the case of natural Stevia (unprocessed).


(1) García-Almeida, J.M. et al. (2013). “Una visión global y actual de los edulcorantes. Aspectos de regulación”. Nutr Hosp, 28(4): 17-31 URL:

(2) NutriMedia (2018). “Los edulcorantes son perjudiciales para la salud”. URL:

(3) Marcos Vázquez. (2014). “Endulzantes naturales y artificiales: los mejores y los peores”. Fitness Revolucionario. URL:

(4) Revenga, J. (2016). “¿Son insanos los edulcorantes?”. El Comidista. El País. URL:

(5) Instituto Nacional del Cáncer (2019). ¿Existe asociación entre edulcorantes artificiales y cáncer? URL:

(6) Stemmler, B. (2016). “Ciclamato sódico, ¿por qué es tan polémico?” En buenas manos. URL:

(7) Schiffman, S.S. et al. (2013). “Sucralose, a synthetic organochlorine sweetener: overview of biological issues”. J Toxicol Environ Health, 16(7): 399-451. URL:

(8) Actualidad RT. (2013). “El aspartame de Monsanto, un dulce de muerte”. URL:

(9) Toews, I. et al. (2019). “Association between intake of non-sugar sweeteners and health outcomes: systematic review and meta-analysis of randomized and non-randomized controlled trials and observational studies”. BMJ, k4718. URL:

(10) Pearlman, M. et al. (2017). “The Association between artificial sweeteners and obesity”. Current Gastroenterology Reports, 19(12). URL: