Aspartame, low-calorie sweeteners and disease: Regulatory safety and epidemiological issues

One-pot derivatization spectrofluorimetric method for detection of aspartame in sweetener commercial tablets and soft drinks: Greenness assessments of the methodology

Aspartame is an artificial sweetener used in drinks and many foods. International Agency for Research on Cancer classified aspartame as possibly carcinogenic to humans (IARC Group 2B). In this study, a sensitive and selective spectrofluorimetric method was developed to detect aspartame. The method is based on switching on the fluorescence activity of aspartame upon its condensation with O-phthalaldehyde (Roth's reaction) in the presence of 2-mercaptoethanol. The reaction product was detected fluorometrically at λem of 438 nm after λex of 340 nm. All reaction conditions required to yield the optimal fluorescence intensity were observed and investigated. Furthermore, the approach was validated according to ICH guidelines. Upon plotting the concentrations of aspartame against their associated fluorescence intensity values, the relationship between the two variables was linear within the range of 0.5-3.0 μg/mL. Furthermore, the method was employed to analyze the quantity of aspartame in commercial packages and soft drinks with an acceptable level of recovery. In addition, the Green Solvents Selecting Tool, Complementary Green Analytical Procedure Index, and the Analytical Greenness Metric tool were used to evaluate the sustainability and the greenness of the developed methodology.

Stability of aspartame in the soft drinks: Identification of the novel phototransformation products and their toxicity evaluation

Photolytic transformation of aspartame - a widely used artificial sweetener - under the simulated sunlight was studied for the first time. The experiments were conducted in pH range of 2.5 - 7.0 and in eight soft drinks available in the market. The highest degradation rate in the tested buffered solutions was observed under the neutral pH conditions. Irradiation of the soft drinks resulted in significantly (up to tenfold) faster degradation of aspartame, regardless of its initial concentration in the beverage. Such considerable acceleration of decomposition, not reported for aspartame so far, was ascribed to influence of the co-occurring ingredients, which can act as the photosensitizers. These findings indicate that some formulations may be particularly unfavorable in the context of aspartame photostability. Qualitative analysis of the studied processes revealed formation of six phototransformation products including three previously not described. In silico estimation of toxicity showed that some of the identified photoproducts, including the novel phenolic derivatives, may be more harmful than the parent compound. Taking into account relatively extensive formation of those products in the soft drinks, such finding may be particularly important from the food safety point of view.

Daily Early-Life Exposures to Diet Soda and Aspartame Are Associated with Autism in Males: A Case-Control Study

Since its introduction, aspartame-the leading sweetener in U.S. diet sodas (DS)-has been reported to cause neurological problems in some users. In prospective studies, the offspring of mothers who consumed diet sodas/beverages (DSB) daily during pregnancy experienced increased health problems. We hypothesized that gestational/early-life exposure to ≥1 DS/day (DSearly) or equivalent aspartame (ASPearly: ≥177 mg/day) increases autism risk. The case-control Autism Tooth Fairy Study obtained retrospective dietary recalls for DSB and aspartame consumption during pregnancy/breastfeeding from the mothers of 235 offspring with autism spectrum disorder (ASD: cases) and 121 neurotypically developing offspring (controls). The exposure odds ratios (ORs) for DSearly and ASPearly were computed for autism, ASD, and the non-regressive conditions of each. Among males, the DSearly odds were tripled for autism (OR = 3.1; 95% CI: 1.02, 9.7) and non-regressive autism (OR = 3.5; 95% CI: 1.1, 11.1); the ASPearly odds were even higher: OR = 3.4 (95% CI: 1.1, 10.4) and 3.7 (95% CI: 1.2, 11.8), respectively (p < 0.05 for each). The ORs for non-regressive ASD in males were almost tripled but were not statistically significant: DSearly OR = 2.7 (95% CI: 0.9, 8.4); ASPearly OR = 2.9 (95% CI: 0.9, 8.8). No statistically significant associations were found in females. Our findings contribute to the growing literature raising concerns about potential offspring harm from maternal DSB/aspartame intake in pregnancy.

Aspartame Safety as a Food Sweetener and Related Health Hazards

Aspartame is the methyl-ester of the aspartate-phenylalanine dipeptide. Over time, it has become a very popular artificial sweetener. However, since its approval by the main food safety agencies, several concerns have been raised related to neuropsychiatric effects and neurotoxicity due to its ability to activate glutamate receptors, as well as carcinogenic risks due to the increased production of reactive oxygen species. Within this review, we critically evaluate reports concerning the safety of aspartame. Some studies evidenced subtle mood and behavioral changes upon daily high-dose intake below the admitted limit. Epidemiology studies also evidenced associations between daily aspartame intake and a higher predisposition for malignant diseases, like non-Hodgkin lymphomas and multiple myelomas, particularly in males, but an association by chance still could not be excluded. While the debate over the carcinogenic risk of aspartame is ongoing, it is clear that its use may pose some dangers in peculiar cases, such as patients with seizures or other neurological diseases; it should be totally forbidden for patients with phenylketonuria, and reduced doses or complete avoidance are advisable during pregnancy. It would be also highly desirable for every product containing aspartame to clearly indicate on the label the exact amount of the substance and some risk warnings.

Repeated co-exposure to aflatoxin B1 and aspartame disrupts the central nervous system homeostasis: Behavioral, biochemical, and molecular insights

Several studies demonstrated the toxicity of aspartame (ASP) and aflatoxin B₁ (AFB₁ ) in preclinical models. Although the majority of these reports assessed the toxic effects of each substance separately, their concomitant exposure and hazardous consequences are scarce. Importantly, the deleterious effects at the central nervous system caused by ASP and AFB₁ co-exposure are rarely addressed. We evaluated if concomitant exposure to AFB₁ and ASP would cause behavioral impairment and alteration in oxidative status of the brain in male rats. Animals received once a day for 14 days AFB₁ (250 µg/kg, intragastric gavage [i.g.]), ASP (75 mg/kg, i.g.), or both substances (association). On day 14, they were subjected to behavioral evaluation, and biochemical and molecular parameters of oxidative status were measured in the cerebral cortex and hippocampus. In the open field test, AFB₁ and combination treatments modified the motor, exploratory, and grooming behavior. In the splash test, all treatments caused a reduction in grooming time compared to the control group. An increase in thiobarbituric acid-reactive substances content induced by AFB₁ and combination treatments was observed. The antioxidant defenses (vitamin C, nonprotein sulfhydryl, and ferric reducing antioxidant power) were impaired in all groups compared to control. Regarding molecular evaluation, mitochondrial superoxide dismutase-2 immunoreactivity decreased after AFB₁ or ASP exposition in the hippocampus. Thus, co-exposure to ASP and AFB₁ was potentially more toxic because it aggravated behavioral impairments and oxidative status disbalance in comparison to the groups that received only ASP or AFB₁ . Therefore, our data suggest that those substances caused a disruption in brain homeostasis.

Long-term intake of aspartame-induced cardiovascular toxicity is reflected in altered histochemical parameters, evokes oxidative stress, and trigger P53-dependent apoptosis in a mouse model

Aspartame (ASP) is probably the best known artificial sugar substitute that is used widely in food. Many experimental studies have reported the toxicity of long-term administration of ASP in various organ tissues. However, there is little evidence available about the nature and mechanisms of the adverse effects of long-term consumption of ASP on the cardiovascular system. This study was conducted to evaluate the possible effects of ASP on heart tissue. For this study 36 mature male mice were divided into one control group and three groups which received respectively 40 mg/kg, 80 mg/kg and 160 mg/kg ASP orally, for 90 days. ASP at the doses of 80 and 160 mg/kg increased the serum content of malondialdehyde (MDA), but decreased serum nitric oxide (NO), creatine kinase (CK) and CK-MB, as well as blood superoxide dismutase (SOD) levels. Serum level of total anti-oxidant capacity (TAC) in blood was also reduced in serum at the dose of 80 mg/kg. Histochemical staining, including Periodic acid-Schiff, Masson's trichrome and Verhoeff-van Gieson staining, indicated that ASP at doses of 80 and 160 mg/kg reduced glycogen deposition and decreased the number of collagen and elastic fibres in the cardiac tissue. The cardiac expression of pro-apoptotic genes, including P53, Bax, Bcl-2 and Caspase-3, was modulated at the dose of 160 mg/kg. Moreover, transcription of Caspase-3 was up-regulated at the dose of 80 mg/kg. In conclusion, long-term consumption of ASP any higher than the acceptable daily intake (40 mg/kg) appears to act by promoting oxidative stress, has the potential to alter both histopathological and biochemical parameters, and induces P53-dependent apoptosis in cardiac tissue.

No Association between Low-Calorie Sweetener (LCS) Use and Overall Cancer Risk in the Nationally Representative Database in the US: Analyses of NHANES 1988-2018 Data and 2019 Public-Use Linked Mortality Files

Low-calorie sweeteners (LCS) serve to replace added sugars in beverages and foods. The present goal was to explore any potential links between LCS use and cancer risk using the nationally representative National Health and Nutrition Examination Surveys 1988-2018 linked to 2019 Public-Use Linked Mortality Files. Analyses were based on dietary intakes from 1988-1994 NHANES (n = 15,948) and 1999-2018 NHANES (n = 48,754) linked to mortality data. The 1988-1994 NHANES separated aspartame from saccharin consumption; later data did not. LCS consumers were more likely to be older, female, non-Hispanic White, and with higher education and incomes compared to nonconsumers. LCS consumers were less likely to smoke and had higher HEI-2015 scores indicating higher-quality diets. In the cross-sectional NHANES data, LCS use was associated with higher BMI and higher prevalence of obesity and diabetes. There was no indication that aspartame, saccharin, or all LCS had any impact on overall cancer mortality. By using nonconsumers as the reference group, the hazard ratio (95th confidence interval, CI) group trend for tertiles of LCS use for 1988-1994 for aspartame was 1.00 (0.89-1.12), for saccharin 0.96 (0.79-1.10), and for 1988-2018 for all LCS was 0.92 (0.88-1.101). The null group trend effects were seen for analyses stratified by age/gender. The present analyses confirm past US-based reports that LCS use was associated with higher socioeconomic status, lower prevalence of smoking, and generally higher-quality diets. No association with cancer mortality was observed.

Effect of aspartame on survival, morphological and molecular levels of Polyrhachis vicina Roger (Hymenoptera, Formicidae)

Aspartame is a food additive that is widely used in the food industry. Previous data have shown that aspartame is toxic to humans and animals. However, there are few reports on the effect of aspartame on social insects living in the soil. The present study was designed to evaluate aspartame toxicity for Polyrhachis vicina Roger. Five dosages of aspartame were fed to the workers and 40 mg/kg (acceptable daily intake, ADI) aspartame was chosen to feed the 4th instar larvae, pupae, females and males in P. vicina. The results showed that the effect of aspartame on the survival rate of workers was in a time and dose dependent manner. The survival rate of 4th instar larvae, pupae and males decreased at 40 mg/kg aspartame. Meanwhile, we found that aspartame toxicity can cause weight and morphological changes. These changes may be related to the abnormal gene expression of Ecdysone receptor, Tailless and Extradenticle of P. vicina (PvEcR, PvTll and PvExd) resulting from aspartame treatment. The present study confirms the effect of aspartame toxicity on P. vicina even at the ADI dosage.

Artificial sweeteners and cancer risk: Results from the NutriNet-Santé population-based cohort study

BACKGROUND

The food industry uses artificial sweeteners in a wide range of foods and beverages as alternatives to added sugars, for which deleterious effects on several chronic diseases are now well established. The safety of these food additives is debated, with conflicting findings regarding their role in the aetiology of various diseases. In particular, their carcinogenicity has been suggested by several experimental studies, but robust epidemiological evidence is lacking. Thus, our objective was to investigate the associations between artificial sweetener intakes (total from all dietary sources, and most frequently consumed ones: aspartame [E951], acesulfame-K [E950], and sucralose [E955]) and cancer risk (overall and by site).

METHODS AND FINDINGS

Overall, 102,865 adults from the French population-based cohort NutriNet-Santé (2009-2021) were included (median follow-up time = 7.8 years). Dietary intakes and consumption of sweeteners were obtained by repeated 24-hour dietary records including brand names of industrial products. Associations between sweeteners and cancer incidence were assessed by Cox proportional hazards models, adjusted for age, sex, education, physical activity, smoking, body mass index, height, weight gain during follow-up, diabetes, family history of cancer, number of 24-hour dietary records, and baseline intakes of energy, alcohol, sodium, saturated fatty acids, fibre, sugar, fruit and vegetables, whole-grain foods, and dairy products. Compared to non-consumers, higher consumers of total artificial sweeteners (i.e., above the median exposure in consumers) had higher risk of overall cancer (n = 3,358 cases, hazard ratio [HR] = 1.13 [95% CI 1.03 to 1.25], P-trend = 0.002). In particular, aspartame (HR = 1.15 [95% CI 1.03 to 1.28], P = 0.002) and acesulfame-K (HR = 1.13 [95% CI 1.01 to 1.26], P = 0.007) were associated with increased cancer risk. Higher risks were also observed for breast cancer (n = 979 cases, HR = 1.22 [95% CI 1.01 to 1.48], P = 0.036, for aspartame) and obesity-related cancers (n = 2,023 cases, HR = 1.13 [95% CI 1.00 to 1.28], P = 0.036, for total artificial sweeteners, and HR = 1.15 [95% CI 1.01 to 1.32], P = 0.026, for aspartame). Limitations of this study include potential selection bias, residual confounding, and reverse causality, though sensitivity analyses were performed to address these concerns.

CONCLUSIONS

In this large cohort study, artificial sweeteners (especially aspartame and acesulfame-K), which are used in many food and beverage brands worldwide, were associated with increased cancer risk. These findings provide important and novel insights for the ongoing re-evaluation of food additive sweeteners by the European Food Safety Authority and other health agencies globally.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03335644.

Toxicological and Nutraceutical Screening Assays of Some Artificial Sweeteners

Artificial sweeteners are food additives worldwide used instead of fructose or glucose in many diet beverages. Furthermore, diet beverages intake has been increasing every year. Thus, some food agencies should regulate it based on toxicological studies. Debates and controversial results are demonstrated, and authority can revise its decision on the basis of new data reporting toxicological effects since cyclamate has been forbidden in some countries. Therefore, the aim of this study was to report new data about the toxicity of acesulfame-k, aspartame, and cyclamate, which are useful for authority agencies, determining the toxic potential and nutraceutical capabilities of these compounds. The toxicity, antitoxicity, genotoxicity, antigenotoxicity, and life expectancy assays were carried out in Drosophila as an in vivo model. In addition, in vitro HL-60 line cell was used to evaluate the chemopreventive activity determining the cytotoxic effect and the capability of producing DNA damage due to internucleosomal fragmentation or DNA strand breaks. Furthermore, the methylated status of these cancer cells treated with the tested compounds was assayed as a cancer therapy. Our results demonstrated that all tested compounds were neither toxic nor genotoxic, whereas these compounds resulted in antigenotoxic and cytotoxic substances, except for cyclamate. Aspartame showed antitoxic effects in Drosophila. All tested compounds decreased the quality of life of this in vivo organism model. Acesulfame-k, aspartame, and cyclamate induced DNA damage in the HL-60 cell line in the comet assay, and acesulfame-k generally increased the methylation status. In conclusion, all tested artificial sweeteners were safe compounds at assayed concentrations since toxicity and genotoxicity were not significantly induced in flies. Moreover, Aspartame and Cyclamate showed protective activity against a genotoxin in Drosophila Regarding nutraceutical potential, acesulfame-k and aspartame could be demonstrated to be chemopreventive due to the cytotoxicity activity shown by these compounds. According to DNA fragmentation and comet assays, a necrotic way could be the main mechanism of death cells induced by acesulfame-k and aspartame. Finally, Acesulfame-K hypermethylated repetitive elements, which are hypomethylated in cancer cells resulting in a benefit to humans.

Zebrafish Behavioral Phenomics Links Artificial Sweetener Aspartame to Behavioral Toxicity and Neurotransmitter Homeostasis

Artificial sweeteners (ASs) are extensively used as food additives in drinks and beverages to lower calorie intake and prevent lifestyle diseases such as obesity. Although clinical and epidemiological data revealed the link between the chronic overconsumption of ASs and adverse health effects, there still exist controversies over the potential adverse neural toxic effect of ASs such as aspartame (APM), with acceptable daily intake (ADI) for a long time, on human health. In addition, whether APM and its metabolites are neurotoxic remains debatable due to a lack of data from an animal experiment or clinical investigation. Herein, to fully describe the potential neurological effect of APM, adult zebrafish served as the animal model to assess neurophysiological alteration induced by APM exposure within the range of the ADI (1, 10, and 100 mg/L) for 2 months. A cohort of standardized neurobehavioral phenotyping assays was conducted, including light/dark preference tests (LDP), novel tank diving tests, novel object recognition tests, social interaction tests, and color preference tests. For instance, in the LDP test, saccharin remarkably decreased the swimming time of zebrafish in the DARK part from 111 ± 10.8 (control group) to 72.2 ± 11.4 (100 mg/L groups). Besides, brain chemistry involved in the alteration of total neurotransmitters was determined by LC-MS/MS to confirm the behavioral results. Overall, current research studies revealed that APM within the range of the ADI altered the total behavioral profiles of zebrafish and disturbed the homeostasis of neurotransmitters in the brain. The present study has established a set of experimental paradigms, revealing the standardized procedure of using adult zebrafish to determine the neural activity or toxicity of AS molecules phenotypically. Zebrafish behavioral phenotyping methods, which were characterized by a cohort of behavioral fingerprints, can link the phenotypical alteration to changes in neurotransmitters in the brain, so as to provide a predictive reference for the further exploration of the molecular mechanism of phenotypic changes induced by ASs.

Hepatic susceptibility to oxidative damage after repeated concomitant exposure to aspartame and aflatoxin B1 in rats

The potential interactions among food additives/contaminants and the consequences to biological systems is a topic that is rarely addressed in scientific literature. Thus, the current study investigated if the combined administration of ASP and AFB₁ would impair hepatic and renal oxidative status. Male Wistar rats received during 14 days once a day ASP (75 mg/Kg) and/or AFB₁ (250 µg/Kg) through intragastric route. At the end of experimental protocol, samples of liver and kidneys were collected for assessing biochemical markers of oxidative status. In the hepatic tissue, the treatment with a single substance (ASP or AFB₁) caused an increase in TBARS levels, and a reduction in non-enzymatic antioxidant defenses (Vit C and NPSH levels and FRAP test). In the kidneys, TBARS levels were increased only in the group that received ASP + AFB₁. The association reduced NPSH content, while the treatment with AFB₁ reduced the FRAP levels. GST and CAT activities were increased in all treatments. Overall, ASP and AFB1 association presented higher toxic effects to the tissues. To the best of our knowledge, this is the first study demonstrating that the associated use of both ASP and AFB1 induces more extensive injuries in comparison to the effects caused by each one alone. Therefore, these data demonstrated that concomitant exposure to ASP and AFB₁ potentiated their oxidative damage in hepatic tissue, suggesting that this organ is particularly sensitive to the toxic action induced by these substances.

Self-assembly of artificial sweetener aspartame adversely affects phospholipid membranes: plausible reason for its deleterious effects

The prolonged intake of the artificial sweetener aspartame is known to have deleterious effects. Our biophysical experimentations indicate that aspartame forms self-assembled cytotoxic fibrillar etiologies that affect the intrinsic integrity of the phospholipid membrane bilayer through electrostatic interaction and hydrophobic insertion, thereby making the membrane less rigid and more heterogeneous.

Aspartame-True or False? Narrative Review of Safety Analysis of General Use in Products

Aspartame is a sweetener introduced to replace the commonly used sucrose. It was discovered by James M. Schlatter in 1965. Being 180-200 times sweeter than sucrose, its intake was expected to reduce obesity rates in developing countries and help those struggling with diabetes. It is mainly used as a sweetener for soft drinks, confectionery, and medicines. Despite its widespread use, its safety remains controversial. This narrative review investigates the existing literature on the use of aspartame and its possible effects on the human body to refine current knowledge. Taking to account that aspartame is a widely used artificial sweetener, it seems appropriate to continue research on safety. Studies mentioned in this article have produced very interesting results overall, the current review highlights the social problem of providing visible and detailed information about the presence of aspartame in products. The studies involving the impact of aspartame on obesity, diabetes mellitus, children and fetus, autism, neurodegeneration, phenylketonuria, allergies and skin problems, its cancer properties and its genotoxicity were analyzed. Further research should be conducted to ensure clear information about the impact of aspartame on health.

A rational review on the effects of sweeteners and sweetness enhancers on appetite, food reward and metabolic/adiposity outcomes in adults

Numerous strategies have been investigated to overcome the excessive weight gain that accompanies a chronic positive energy balance. Most approaches focus on a reduction of energy intake and the improvement of lifestyle habits. The use of high intensity artificial sweeteners, also known as non-caloric sweeteners (NCS), as sugar substitutes in foods and beverages, is rapidly developing. NCS are commonly defined as molecules with a sweetness profile of 30 times higher or more that of sucrose, scarcely contributing to the individual's net energy intake as they are hardly metabolized. The purpose of this review is first, to assess the impact of NCS on eating behaviour, including subjective appetite, food intake, food reward and sensory stimulation; and secondly, to assess the metabolic impact of NCS on body weight regulation, glucose homeostasis and gut health. The evidence reviewed suggests that while some sweeteners have the potential to increase subjective appetite, these effects do not translate in changes in food intake. This is supported by a large body of empirical evidence advocating that the use of NCS facilitates weight management when used alongside other weight management strategies. On the other hand, although NCS are very unlikely to impair insulin metabolism and glycaemic control, some studies suggest that NCS could have putatively undesirable effects, through various indirect mechanisms, on body weight, glycemia, adipogenesis and the gut microbiota; however there is insufficient evidence to determine the degree of such effects. Overall, the available data suggests that NCS can be used to facilitate a reduction in dietary energy content without significant negative effects on food intake behaviour or body metabolism, which would support their potential role in the prevention of obesity as a complementary strategy to other weight management approaches. More research is needed to determine the impact of NCS on metabolic health, in particular gut microbiota.

Antihyperglycemic and hepatoprotective properties of miracle fruit (Synsepalum dulcificum) compared to aspartame in alloxan-induced diabetic mice

OBJECTIVE

This study was undertaken to investigate the antihyperglycemic potential of miracle fruit (MF) as well as its hepatic safety as compared to aspartame in alloxan-induced diabetic mice.

METHODS

MF extracts were prepared and screened for their phytochemical composition using high-performance liquid chromatography (HPLC). Total phenolic, flavonoid and tannin contents and antioxidant potential were also determined. Additionally, MF was evaluated for its sensory attributes. For in vivo work, MF ethanol extract at high (MFH: 500 mg/kg body weight [BW]) and low (MFL: 250 mg/kg BW) doses as well as aspartame were injected intraperitoneally into alloxan-induced diabetic mice. Blood glucose levels were determined following acute and subchronic treatment. At the end of the study, animals were sacrificed, serum was collected for biochemical analysis and liver tissues were obtained for histopathological examination.

RESULTS

MF ethanol extract contained more flavonoids and tannins, and had higher 1,1-diphenyl-1-picrylhydrazyl radical-scavenging activity (79.61%) compared to MF aqueous extract (P < 0.05). HPLC analysis of MF ethanol extract also revealed the presence of 10 antioxidants with quercetin comprising the major polyphenol. Additionally, sensory analysis of MF showed that its intake is effective in masking undesirable sourness. Subchronic administration of MFH proved amelioration of hyperglycemia in mice as compared to aspartame. Moreover, aspartame treatment significantly elevated (P < 0.05) the level of alanine aminotransferase and had destructive effects on the liver histopathology; however, hepatic architecture was restored by low and high doses of MF.

CONCLUSION

MF is an effective antihyperglycemic with hepatoprotective properties that can be used as a healthier alternative sweetening agent in place of aspartame for sour beverages.

The Use of Nonnutritive Sweeteners in Children

The prevalence of nonnutritive sweeteners (NNSs) in the food supply has increased over time. Not only are more children and adolescents consuming NNSs, but they are also consuming a larger quantity of NNSs in the absence of strong scientific evidence to refute or support the safety of these agents. This policy statement from the American Academy of Pediatrics is intended to provide the pediatric provider with a review of (1) previous steps taken for approved use of NNSs, (2) existing data regarding the safety of NNS use in the general pediatric population, (3) what is known regarding the potential benefits and/or adverse effects of NNS use in children and adolescents, (4) identified gaps in existing knowledge and potential areas of future research, and (5) suggested talking points that pediatricians may use when discussing NNS use with families.

Behavioural and biochemical effects of one-week exposure to aflatoxin B1 and aspartame in male Wistar rats

Food products are susceptible to contamination by mycotoxins, and aflatoxin B1 (AFB1) stands as the most toxic among them. AFB1 intoxication results in distinct signs, including widespread systemic toxicity. Aspartame (ASP) is an artificial sweetener used as a sugar substitute in many products, and compelling evidence indicates ASP can be toxic. Interestingly, mechanisms underlying ASP and AFB1 toxicity involve oxidative stress. In this context, concomitant use of ASP and AFB1 in a meal may predispose to currently unidentified behavioural and biochemical changes. Therefore, we evaluated the effect of AFB1 (250 μg/kg, intragastrically (i.g.)) and/or ASP (75 mg/kg, i.g.) exposure for 7 days on behavioural and biochemical markers of oxidative stress in male Wistar rats. AFB1 and/or ASP increased hepatic glutathione S-transferase (GST) activity when compared to controls. In the kidneys, increased GST activity was detected in AFB1 and AFB1+ASP groups. In addition, AFB1 and or ASP elicited behavioural changes in the open field, marble burying and splash tests, however no additive effects were detected. Altogether, present data suggest AFB1 and ASP predispose to anxiety- and obsessive-compulsive-like symptoms, as well as to enzymatic defence system imbalance in liver and kidney of Wistar rats.

Measuring Artificial Sweeteners Toxicity Using a Bioluminescent Bacterial Panel

Artificial sweeteners have become increasingly controversial due to their questionable influence on consumers' health. They are introduced in most foods and many consume this added ingredient without their knowledge. Currently, there is still no consensus regarding the health consequences of artificial sweeteners intake as they have not been fully investigated. Consumption of artificial sweeteners has been linked with adverse effects such as cancer, weight gain, metabolic disorders, type-2 diabetes and alteration of gut microbiota activity. Moreover, artificial sweeteners have been identified as emerging environmental pollutants, and can be found in receiving waters, i.e., surface waters, groundwater aquifers and drinking waters. In this study, the relative toxicity of six FDA-approved artificial sweeteners (aspartame, sucralose, saccharine, neotame, advantame and acesulfame potassium-k (ace-k)) and that of ten sport supplements containing these artificial sweeteners, were tested using genetically modified bioluminescent bacteria from E. coli. The bioluminescent bacteria, which luminesce when they detect toxicants, act as a sensing model representative of the complex microbial system. Both induced luminescent signals and bacterial growth were measured. Toxic effects were found when the bacteria were exposed to certain concentrations of the artificial sweeteners. In the bioluminescence activity assay, two toxicity response patterns were observed, namely, the induction and inhibition of the bioluminescent signal. An inhibition response pattern may be observed in the response of sucralose in all the tested strains: TV1061 (MLIC = 1 mg/mL), DPD2544 (MLIC = 50 mg/mL) and DPD2794 (MLIC = 100 mg/mL). It is also observed in neotame in the DPD2544 (MLIC = 2 mg/mL) strain. On the other hand, the induction response pattern may be observed in its response in saccharin in TV1061 (MLIndC = 5 mg/mL) and DPD2794 (MLIndC = 5 mg/mL) strains, aspartame in DPD2794 (MLIndC = 4 mg/mL) strain, and ace-k in DPD2794 (MLIndC = 10 mg/mL) strain. The results of this study may help in understanding the relative toxicity of artificial sweeteners on E. coli, a sensing model representative of the gut bacteria. Furthermore, the tested bioluminescent bacterial panel can potentially be used for detecting artificial sweeteners in the environment, using a specific mode-of-action pattern.

Revisiting the safety of aspartame

Aspartame is a synthetic dipeptide artificial sweetener, frequently used in foods, medications, and beverages, notably carbonated and powdered soft drinks. Since 1981, when aspartame was first approved by the US Food and Drug Administration, researchers have debated both its recommended safe dosage (40 mg/kg/d) and its general safety to organ systems. This review examines papers published between 2000 and 2016 on both the safe dosage and higher-than-recommended dosages and presents a concise synthesis of current trends. Data on the safe aspartame dosage are controversial, and the literature suggests there are potential side effects associated with aspartame consumption. Since aspartame consumption is on the rise, the safety of this sweetener should be revisited. Most of the literature available on the safety of aspartame is included in this review. Safety studies are based primarily on animal models, as data from human studies are limited. The existing animal studies and the limited human studies suggest that aspartame and its metabolites, whether consumed in quantities significantly higher than the recommended safe dosage or within recommended safe levels, may disrupt the oxidant/antioxidant balance, induce oxidative stress, and damage cell membrane integrity, potentially affecting a variety of cells and tissues and causing a deregulation of cellular function, ultimately leading to systemic inflammation.

Dose and time dependent ototoxicity of aspartame in rats

CONCLUSION

Low-dose administration of Aspartame (Ap) did not produce a significant ototoxic effect at the end of the 6th month. However, duration of the ototoxic effect is shortened and severity of the effect is increased as dose and duration of Ap administration is increased.

OBJECTIVES

While Ap toxicity has been studied in short- and long-term studies, its effects on hearing have not been investigated. This study was conducted to evaluate the effects of long-term consumption of Ap administered in various doses on hearing status of rats.

METHODS

The study included 54 female Wistar Albino rats. Ap was given for 6 months to the rats. The groups were assigned according to levels of Ap dosage. DPOAE and ABR tests were utilized for serial hearing evaluations. Serial hearing measurement times were designed as baseline, 1st week, 2nd week, 1st, 2nd, 3rd, and 6th months.

RESULTS

While audiological parameters deteriorated with 100 mg/kg/day dose after the 3rd month, ABR thresholds were elevated and DPOAE values were significantly decreased in 500 mg/kg/day and 1000 mg/kg/day applications after the 2nd month. In 2000 mg/kg/day and 4000 mg/kg/day applications, deteriorations in audiological parameters were detected as early as the first and second months; respectively.

Development of an HPLC Method with an ODS Column to Determine Low Levels of Aspartame Diastereomers in Aspartame

α-L-Aspartyl-D-phenylalanine methyl ester (L, D-APM) and α-D-aspartyl-L-phenylalanine methyl ester (D, L-APM) are diastereomers of aspartame (N-L-α-Aspartyl-L-phenylalanine-1-methyl ester, L, L-APM). The Joint FAO/WHO Expert Committee on Food Additives has set 0.04 wt% as the maximum permitted level of the sum of L, D-APM and D, L-APM in commercially available L, L-APM. In this study, we developed and validated a simple high-performance liquid chromatography (HPLC) method using an ODS column to determine L, D-APM and D, L-APM in L, L-APM. The limits of detection and quantification, respectively, of L, D-APM and D, L-APM were found to be 0.0012 wt% and 0.004 wt%. This method gave excellent accuracy, repeatability, and reproducibility in a recovery test performed on five different days. Moreover, the method was successfully applied to the determination of these diastereomers in commercial L, L-APM samples. Thus, the developed method is a simple, useful, and practical tool for determining L, D-APM and D, L-APM levels in L, L-APM.

The potential application of a biomarker approach for the investigation of low-calorie sweetener exposure

Low-calorie sweeteners (LCS) are commonly used as sugar substitutes in the diet to provide a desired sweet taste without increased energy intake. The number of LCS available on the market has increased considerably over the years and despite extensive evaluation of their safety prior to approval, debate continues around the effects of consumption on health. In Europe, Member States are obligated to monitor exposure to LCS and methods currently used tend to rely on self-reported dietary intake data alongside LCS concentrations in products. However, the acquisition of accurate data can be costly in terms of resources and time and are inherently imprecise. Although LCS are intensely sweet, they are chemically diverse and a limitation of many studies investigating the health effects of consumption is that they often fail to discern intakes of individual LCS. An approach which objectively assesses intakes of individual LCS would therefore allow robust investigations of their possible effects on health. Biomarker approaches have been utilised for the objective investigation of intakes of a range of dietary components and the feasibility of any such approach depends upon its validity as well as its applicability within the target population. This review aims to provide an overview of current understanding of LCS intake and explore the possibility of implementing a biomarker approach to enhance such understanding. Several commonly used LCS, once absorbed into the body, are excreted via the kidneys; therefore a urinary biomarker approach may be possible for the investigation of short-term exposure to these compounds.

Alteration of the substrate specificity of l-amino acid ligase and selective synthesis of Met-Gly as a salt taste enhancer

Dipeptides have unique physiological functions. This study focused on the salt-taste-enhancing dipeptide Met-Gly. BL00235, an l-amino acid ligase from Bacillus licheniformis NBRC12200, synthesizes Met-Gly as a major product as well as Met-Met as a by-product. To alter the substrate specificity of BL00235 and synthesize Met-Gly selectively, we chose to alter Pro85 residue based on the BL00235 crystal structure. We predicted that Met might be not recognized as a C-terminal substrate by occupying the space around C-terminal substrate. Pro85 was replaced with Phe, Tyr, and Trp, which have bulky aromatic side chains, by site-directed mutagenesis. These mutants lost the capacity to synthesize Met-Met, during the synthesis of Met-Gly. Furthermore, they did not synthesize Met-Met, even when methionine was used as a substrate. These results show that the amino acid residue at position 85 has a key role in C-terminal substrate specificity.

Assessing developmental toxicity of caffeine and sweeteners in medaka (Oryzias latipes)

The use of artificial sweeteners (ASWs) has increased and become more widespread, and consequently ASWs have appeared in aquatic environments around the world. However, their safety to the health of humans and wildlife remains inconclusive. In this study, using medaka embryos (Oryzias latipes), we investigated developmental toxicity of aspartame (ASP) and saccharin (SAC). Since ASWs are often consumed with caffeine (CAF) and CAF with sucrose (SUC), we tested biological activities of these four substances and the mixtures of CAF with each sweetener. The embryos were exposed to ASP at 0.2 and 1.0 mM, SAC at 0.005 and 0.050 mM, CAF at 0.05 and 0.5 mM, or SUC at 29 and 146 mM, starting from less than 5 h post fertilization until hatch. Control embryos were treated with embryo solution only. Several endpoints were used to evaluate embryonic development. Some of the hatchlings were also tested for anxiety-like behavior with the white preference test. The results showed that all four substances and the mixtures of CAF with the sweeteners affected development. The most sensitive endpoints were the heart rate, eye density, and hatchling body length. The hatchlings of several treatment groups also exhibited anxiety-like behavior. We then used the Integrated Biological Response (IBR) as an index to evaluate the overall developmental toxicity of the substances. We found that the ranking of developmental toxicity was SAC > CAF > ASP > SUC, and there was a cumulative effect when CAF was combined with the sweeteners.

The carcinogenic effects of aspartame: The urgent need for regulatory re-evaluation

Aspartame (APM) is an artificial sweetener used since the 1980s, now present in >6,000 products, including over 500 pharmaceuticals. Since its discovery in 1965, and its first approval by the US Food and Drugs Administration (FDA) in 1981, the safety of APM, and in particular its carcinogenicity potential, has been controversial. The present commentary reviews the adequacy of the design and conduct of carcinogenicity bioassays on rodents submitted by G.D. Searle, in the 1970s, to the FDA for market approval. We also review how experimental and epidemiological data on the carcinogenic risks of APM, that became available in 2005 motivated the European Commission (EC) to call the European Food and Safety Authority (EFSA) for urgent re-examination of the available scientific documentation (including the Searle studies). The EC has further requested that, if the results of the evaluation should suggest carcinogenicity, major changes must be made to the current APM specific regulations. Taken together, the studies performed by G.D. Searle in the 1970s and other chronic bioassays do not provide adequate scientific support for APM safety. In contrast, recent results of life-span carcinogenicity bioassays on rats and mice published in peer-reviewed journals, and a prospective epidemiological study, provide consistent evidence of APM's carcinogenic potential. On the basis of the evidence of the potential carcinogenic effects of APM herein reported, a re-evaluation of the current position of international regulatory agencies must be considered an urgent matter of public health.