Physiological mechanisms by which non-nutritive sweeteners may impact body weight and metabolism

Non-nutritive Sweeteners: Weight Loss or Weight Gain?

The consumption of non-nutritive sweeteners (NNS) is on the rise among different populations. In parallel, the debate about their potential health benefits and risks remains inconclusive. Numerous published studies elucidate the impact of NNS on general health, weight control, and the risk of certain diseases. However, no definitive conclusions regarding the effect of chronic NNS use on weight have been reached in humans. This review summarizes current evidence related to the biological role of NNS and their subsequent effects on weight. The mechanisms of action through which NNS impact weight are discussed, including their effect on sweet taste receptors, cognition, metabolic and endocrine functions, intestinal microbiota, and adiposity. Conflicting evidence is hindering the formulation of precise recommendations, but the evidence opposing the use of NNS remains weak, and the ultimate impact on weight largely relies on several other behavioral patterns.

A Comprehensive Review of the Effects of Glycemic Carbohydrates on the Neurocognitive Functions Based on Gut Microenvironment Regulation and Glycemic Fluctuation Control

Improper glycemic carbohydrates (GCs) consumption can be a potential risk factor for metabolic diseases such as obesity and diabetes, which may lead to cognitive impairment. Although several potential mechanisms have been studied, the biological relationship between carbohydrate consumption and neurocognitive impairment is still uncertain. In this review, the main effects and mechanisms of GCs' digestive characteristics on cognitive functions are comprehensively elucidated. Additionally, healthier carbohydrate selection, a reliable research model, and future directions are discussed. Individuals in their early and late lives and patients with metabolic diseases are highly susceptible to dietary-induced cognitive impairment. It is well known that gut function is closely related to dietary patterns. Unhealthy carbohydrate diet-induced gut microenvironment disorders negatively impact cognitive functions through the gut-brain axis. Moreover, severe glycemic fluctuations, due to rapidly digestible carbohydrate consumption or metabolic diseases, can impair neurocognitive functions by disrupting glucose metabolism, dysregulating calcium homeostasis, oxidative stress, inflammatory responses, and accumulating advanced glycation end products. Unstable glycemic status can lead to more severe neurological impairment than persistent hyperglycemia. Slow-digested or resistant carbohydrates might contribute to better neurocognitive functions due to stable glycemic response and healthier gut functions than fully gelatinized starch and nutritive sugars.

The Impact of Artificial Sweeteners on Human Health and Cancer Association: A Comprehensive Clinical Review

Artificial sweeteners are sugar substitutes that provide high sweetening power associated with low accompanied calories. In this study, we aim to review the data on the use, benefits, side effects, and cancer risks of artificial sweeteners. We reviewed data in the PubMed, MEDLINE, Google Scholar, Embase, and Scopus databases to search for studies about artificial sweeteners from the inception of the database to July 20, 2023, published in the English language. We discuss systematic reviews and meta-analyses, randomized clinical trials, and observational cohort studies that address the use of artificial sweeteners and their effect on health. In our review, we show that artificial sweeteners have been shown to impact various functions of the gastrointestinal system. Other studies have demonstrated an association with neurologic symptoms such as headache and taste alteration. Moreover, recent studies have established an association between artificial sweeteners and cardiovascular risk and diabetes. Importantly, the majority of research data show no link between the use of artificial sweeteners and cancer risk. Although most studies show that there is no established link between these products and cancer risk, artificial sweeteners are associated with multiple diseases. Hence, more studies are needed to better characterize the effect of artificial sweeteners on human health.

Maternal consumption and perinatal exposure to non-nutritive sweeteners: should we be concerned?

The context for this review is the rapid increase in the use of non-nutritive sweeteners (NNSs) instead of sugar in foods and beverages, a situation so prevalent in some countries that consumers are finding it increasingly challenging to access foods without NNSs. The benefits of consuming NNSs on obesity and diabetes are now being questioned, and studies have shown that they may exert physiological activities, sometimes independently of sweet taste receptor stimulation. Few studies, limited mainly to North American and European countries, have described the consumption of NNSs by pregnant or lactating women and infants. Most focus on beverages rather than foods, but all agree that consumption levels have increased dramatically. Although some studies report a negative impact of NNSs on the risk of preterm birth, increased birth weight and decreased gestational age, the level of evidence is low. Several studies have also reported increased weight gain in infancy, associated with maternal NNS intake. Interestingly, several NNSs have been detected in amniotic fluid and breast milk, usually (but not always) at concentrations below their established detection limit in humans. Unfortunately, the impact of chronic exposure of the fetus/infant to low levels of multiple NNSs is unknown. In conclusion, there is a stark contrast between the galloping increase in the consumption of NNSs and the small number of studies evaluating their impact in at-risk groups such as pregnant and lactating women and infants. Clearly, more studies are needed, especially in Latin America and Asia, to fill these gaps and update recommendations.

Rationale, Design and Participants Baseline Characteristics of a Crossover Randomized Controlled Trial of the Effect of Replacing SSBs with NSBs versus Water on Glucose Tolerance, Gut Microbiome and Cardiometabolic Risk in Overweight or Obese Adult SSB Consumer: Strategies to Oppose SUGARS with Non-Nutritive Sweeteners or Water (STOP Sugars NOW) Trial and Ectopic Fat Sub-Study

BACKGROUND

Health authorities are near universal in their recommendation to replace sugar-sweetened beverages (SSBs) with water. Non-nutritive sweetened beverages (NSBs) are not as widely recommended as a replacement strategy due to a lack of established benefits and concerns they may induce glucose intolerance through changes in the gut microbiome. The STOP Sugars NOW trial aims to assess the effect of the substitution of NSBs (the "intended substitution") versus water (the "standard of care substitution") for SSBs on glucose tolerance and microbiota diversity.

DESIGN AND METHODS

The STOP Sugars NOW trial (NCT03543644) is a pragmatic, "head-to-head", open-label, crossover, randomized controlled trial conducted in an outpatient setting. Participants were overweight or obese adults with a high waist circumference who regularly consumed ≥1 SSBs daily. Each participant completed three 4-week treatment phases (usual SSBs, matched NSBs, or water) in random order, which were separated by ≥4-week washout. Blocked randomization was performed centrally by computer with allocation concealment. Outcome assessment was blinded; however, blinding of participants and trial personnel was not possible. The two primary outcomes are oral glucose tolerance (incremental area under the curve) and gut microbiota beta-diversity (weighted UniFrac distance). Secondary outcomes include related markers of adiposity and glucose and insulin regulation. Adherence was assessed by objective biomarkers of added sugars and non-nutritive sweeteners and self-report intake. A subset of participants was included in an Ectopic Fat sub-study in which the primary outcome is intrahepatocellular lipid (IHCL) by 1H-MRS. Analyses will be according to the intention to treat principle.

BASELINE RESULTS

Recruitment began on 1 June 2018, and the last participant completed the trial on 15 October 2020. We screened 1086 participants, of whom 80 were enrolled and randomized in the main trial and 32 of these were enrolled and randomized in the Ectopic Fat sub-study. The participants were predominantly middle-aged (mean age 41.8 ± SD 13.0 y) and had obesity (BMI of 33.7 ± 6.8 kg/m²) with a near equal ratio of female: male (51%:49%). The average baseline SSB intake was 1.9 servings/day. SSBs were replaced with matched NSB brands, sweetened with either a blend of aspartame and acesulfame-potassium (95%) or sucralose (5%).

CONCLUSIONS

Baseline characteristics for both the main and Ectopic Fat sub-study meet our inclusion criteria and represent a group with overweight or obesity, with characteristics putting them at risk for type 2 diabetes. Findings will be published in peer-reviewed open-access medical journals and provide high-level evidence to inform clinical practice guidelines and public health policy for the use NSBs in sugars reduction strategies.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03543644.

Dietary Polysaccharide-Rich Extract from Noni (Morinda citrifolia L.) Fruit Modified Ruminal Fermentation, Ruminal Bacterial Community and Nutrient Digestion in Cashmere Goats

In two consecutive studies, we evaluated the effects of polysaccharide-rich noni (Morinda citrifolia L.) fruit extract (NFP) on ruminal fermentation, ruminal microbes and nutrient digestion in cashmere goats. In Exp. 1, the effects of a diet containing NFP of 0, 0.1%, 0.2%, 0.4% and 0.55% on in vitro ruminal fermentation at 3, 6, 9, 12 and 24 h were determined, whereas in Exp. 2, fourteen cashmere goats (46.65 ± 3.36 kg of BW ± SD) were randomly assigned to two treatments: the basal diet with or without (CON) supplementation of NFP at 4 g per kg DM (0.4%). The in vitro results showed that NFP linearly increased concentrations of volatile fatty acids (VFA), quadratically decreased ammonia-N concentration, and changed pH, protozoa number, gas production and the microbial protein (MCP) concentration, and was more effective at 0.4% addition, which yielded similar results in ruminal fermentation in Exp. 2. In addition, NFP increased the apparent digestibility of dry matter and crude protein and the abundance of Firmicutes, and reduced the abundance of Bacteroides and Actinobacteria. Ruminococcus_1 was positively associated with VFA concentration. The Rikenellaceae_RC9_gut_group was positively correlated with protozoa and negatively correlated with MCP concentration. Thus, NFP has potential as a ruminal fermentation enhancer for cashmere goats.

Intermittent access training produces greater motivation for a non-drug reinforcer than long access training

It has recently been proposed that the intermittent access (IntA) drug self-administration procedure better produces behavioral changes relevant to addiction than the long access (LgA) procedure. In this version of the IntA procedure, the drug is made available for a 5-min period during each half hour of a 6-h session. In contrast, on the LgA procedure, the drug is available continuously for 6 h. Previous studies have found that IntA drug self-administration produces greater drug motivation, measured by increased progressive ratio breakpoints, than LgA self-administration. It has been hypothesized that this effect is due to the rapid, "spiking" brain levels of the drug, and consequent neuroadaptations, experienced by rats during IntA sessions. However, no study has compared the effects of IntA versus LgA training on reinforcer motivation when using a non-drug reinforcer. The present study compared motivation for a saccharin reinforcer after IntA or LgA training. In Experiment 1, separate groups of rats lever-pressed for saccharin on the IntA or LgA procedures. In Experiment 2, a within-subjects design was used where rats pressed one lever on the IntA procedure and another lever on the LgA procedure for saccharin. In both experiments, IntA training produced greater breakpoints than LgA training. As no drug was used here, spiking drug levels could not have been responsible for the increased saccharin motivation observed after IntA training. Instead, it is proposed that differences in stimulus-reinforcer associations learned during IntA versus LgA training may be responsible for the effect. Future research is needed to determine the extent to which such learning factors may contribute to the increased motivation observed after IntA training with drug reinforcers.

Non-nutritive sweeteners and their impacts on the gut microbiome and host physiology

Non-nutritive sweeteners (NNS) are broadly incorporated into foods, especially those representing a growing share of the beverage market. NNS are viewed as a noncaloric and desirable alternative to sugar-based sweeteners and are thought to contribute to reducing overall caloric intake. While these compounds have been studied extensively and have long been considered inert, new research has presented a different view and raises new questions about the effects of NNS on human physiology. Namely, the influence on glucose responses, the gastrointestinal epithelium, and the gut microbiome. As the gut microbiome is now recognized as a major mediator of human health and perturbations to this community are generally associated with negative health trajectories or overt disease, interactions between NNS and the gut microbiome are of increasing interest to clinicians and researchers. Several NNS compounds are now hypothesized to affect human physiology by modulating the gut microbiome, though the mechanism for this action remains unclear. The purpose of this review is to discuss the history and current knowledge of NNS, their reported utility and effects on host physiology and the gut microbiome, and describes a model for investigating the underlying mechanism behind reported effects of NNS on the gut microbiome.

Effect of Long-term Intake of Nutritive and Non-nutritive Sweeteners on Metabolic Health and Cognition in Adult Male Rats

This study evaluated the effects of long-term intake of nutritive sweeteners (NSs) and non-nutritive sweeteners (NNSs) on body weight, food and energy intake, blood pressure, metabolic parameters, and memory retention in rats. Sixty male Sprague-Dawley rats were randomly divided into six groups (n = 10 per group): control (water),10% sucrose (SUC), aspartame (ASP), sucralose (SCA), stevia (STV), and 5% xylitol (XYL). Pure NSs (SUC and XYL) and NNSs were added to the drinking water for 18 weeks. ASP, SCA, and STV dosage was based on the estimated daily intake limit: 4.1, 2.0, and 3.4 mg/kg/day, respectively. Chronic access to NNSs did not result in any difference in total weight gain of the rats, while it was significantly elevated in the SUC group compared with the control and NNSs groups. Food intake was significantly lower in all NNSs groups compared with SUC and control groups. Sweetened beverage intake volumes were significantly diminished in all NNSs groups compared with intake in SUC and control groups. Total calories consumed were lower for the STV and XYL groups compared with all other groups. Blood pressure and glucose metabolism did not differ significantly between the groups. All sweeteners increased total cholesterol, low-density lipoprotein, and triglyceride levels. Short-term memory was significantly impaired in the ASP group in the novel object recognition task, while long-term memory was impaired in SUC and STV groups. These metabolic and behavioral results suggest that the long-term intake of NSs or NNSs can be associated with peripheral and central effects.

Dose-Response and Substitution Analyzes of Sweet Beverage Consumption and Body Weight in Dutch Adults: The Lifelines Cohort Study

Background/Methods

Prospective studies investigating sweet beverages and body weight associations show inconsistent results. Within the SWEET project, we examined prospective dose-response associations of sugar-sweetened beverages (SSB), low/no-calorie beverages (LNCB), and fruit juice with body weight-related outcomes among 78,286 Dutch adults followed for ~4 years. Baseline intakes were assessed using a validated food-frequency questionnaire (FFQ) with 150 ml representing a standard serving. Outcome variables were body weight change, waist circumference change, overweight/obesity, and abdominal obesity. Associations were investigated by using linear and non-linear dose-response analysis, as well as substitution models while adjusting for multiple socio-demographic, lifestyle, health, and dietary variables.

Results

Participants were 46 ± 13 (mean ± SD) years old and 60% were women. Adjusted dose-response analyzes indicated an association between SSB and LNCB, and both body weight (+0.02 kg/year; SE 0.01 and +0.06 kg/year; SE 0.01) and waist circumference changes (+0.04 cm/year; SE: 0.01 and +0.11 cm/year; SE: 0.01). Associations for overweight/obesity and abdominal obesity incidence were +3% (95%CI: 1.00–1.06) and +2% (95%CI: 0.99–1.06) for SSB and +8% (95%CI: 1.06–1.11) and +5% (95%CI: 1.03–1.07) for LNCB, respectively. Substitution of SSB with LNCB was associated with higher weight change (+0.04 kg/year), waist circumference change (+0.09 cm/year), overweight/obesity incidence (+6%), but not abdominal obesity incidence. For fruit juice, we observed beneficial associations for intake levels below ~1 serving/day with weight, waist circumference change, and overweight/obesity incidence, and no association with abdominal obesity. Subsequent substitution analyzes indicated a small beneficial association for the replacement of SSB with fruit juice on weight (−0.04 kg/year) and waist circumference (−0.04 cm/year), but not with other outcomes.

Conclusions

Overall, our results suggest that habitual consumption of both SSB and LNCB may adversely affect weight-related outcomes. In contrast, fruit juice consumption <150 ml may be beneficial with respect to weight and waist circumference.

Sakarinin İştah, Enerji Alımı ve Serum Ghrelin Üzerinde Etkisi Var mı? Sağlıklı Erkeklerde Randomize, Kontrollü, Çapraz Bir Çalışma

Amaç: Günümüzde şeker yerine enerji içermeyen yapay tatlandırıcılar yaygın olarak kullanılmaktadır. Ancak bilinenin aksine yapay tatlandırıcıların metabolizmayı çeşitli yönlerden etkilediği düşünülmektedir. Bu çalışmanın amacı sakarinin serum ghrelin düzeyi, iştah ve besin tüketimi üzerindeki etkilerini değerlendirmektir. Metod: Randomize, kontrollü ve çapraz olarak yapılan çalışmaya 20-29 yaşları arasında dokuz sağlıklı erkek katılmıştır. Her katılımcıya 300 ml su, 75 gram sakaroz içeren 300 ml su ve 240 miligram sakarin içeren 300 ml su verilmiştir. Başlangıç, 30., 60., 90., 120. ve 180. dakikalarda iştahı değerlendirmek için Görsel Analog Skala uygulanmış ve ghrelin analizi için kan örnekleri alınmıştır. Yüzsekseninci sonra katılımcılar ad libitum beslenmişler ve her uygulama günün sonuna kadar 24 saatlik diyet besin tüketim kaydı tutmuşlardır. Bulgular: Altmışıncı ve 120. dakikalarda sadece su ve sakarinli içeceklerde ortalama ghrelin düzeyi sükroz içeren içeceğe kıyasla daha yüksektir (p

Effect of saccharin, a non-nutritive sweeteners, on insulin and blood glucose levels in healthy young men: A crossover trial

BACKGROUND AND AIMS

Artificial sweeteners used instead of sugar were considered as the best alternatives that have no endocrine effects. However, it has recently been suggested that artificial sweeteners may cause impaired metabolic parameters. The hypothesis of the study was there is an association between acute saccharin consumption and both glycemia and insulin response in young healthy adult men.

METHODS

9 healthy adult males were included in this study. This study randomly provided participants with preloads as (a)300 ml of water, or 300 ml of water sweetened with (b)75 g of sucrose, (c)240 mg of saccharine (adjusted to the sweetness of 75 g of sucrose) 1 h before a standard breakfast.

RESULTS

Compared to mean blood glucose and serum insulin after test drinks consumption, there was only one difference between sucrose and saccharin trials in the 15th minute (117.0 ± 18.70, 95.4 ± 5.64 mg/dl respectively, p < 0.05). At the 60th minute, insulin secretion (0.80 ± 0.27 pg/dl) after the sucrose trial was found significantly higher than the saccharin trial (0.53 ± 0.09 pg/dl) and water (0.49 ± 0.06 pg/dl) (p < 0.05). Although at all intervals (except 90th minute), the mean insulin is higher after the saccharin trial compared to the water trial, these were non-statistically significant differences (p > 0.05).

CONCLUSIONS

Consequently, it was determined that saccharin had no glycemic effect. However, for the effect on serum insulin to be clarified, the long-term effects should be investigated.

Intestinal Alkaline Phosphatase: A Review of This Enzyme Role in the Intestinal Barrier Function

Intestinal alkaline phosphatase (IALP) has recently assumed a special relevance, being the subject of study in the prevention and treatment of certain diseases related to leaky gut. This brush border enzyme (ecto-enzyme) plays an important role in the maintenance of intestinal microbial homeostasis and intestinal barrier function through its ability to dephosphorylate lipopolysaccharide (LPS). This review addresses how IALP and intestinal barrier dysfunction may be implicated in the pathophysiology of specific diseases such as inflammatory bowel disease, necrotizing enterocolitis, and metabolic syndrome. The use of IALP as a possible biomarker to assess intestinal barrier function and strategies to modulate IALP activity are also discussed.

Cephalic phase insulin release: A review of its mechanistic basis and variability in humans

Cephalic phase insulin release (CPIR) is a transient pulse of insulin that occurs within minutes of stimulation from foods or food-related stimuli. Despite decades of research on CPIR in humans, the body of literature surrounding this phenomenon is controversial due in part to contradictory findings . This has slowed progress towards understanding the sensory and neural basis of CPIR, as well as its overall relevance to health. This review examines up-to-date knowledge in CPIR research and identifies sources of CPIR variability in humans in an effort to guide future research. The review starts by defining CPIR and discussing its presumed functional roles in glucose homeostasis and feeding behavior. Next, the types of stimuli that have been reported to elicit CPIR, as well as the sensory and neural mechanisms underlying the response in rodents and humans are discussed, and areas where knowledge is limited are identified. Finally, factors that may contribute to the observed variability of CPIR in humans are examined, including experimental design, test procedure, and individual characteristics. Overall, oral stimulation appears to be important for eliciting CPIR, especially when combined with other sensory modalities (vision, olfaction, somatosensation). While differences in experimental design and testing procedure likely explain some of the observed inter- and intra-study variability, individual differences also appear to play an important role. Understanding sources of these individual differences in CPIR will be key for establishing its health relevance.

Disparities in exposure to television advertising of sugar-sweetened and non-nutritive sweetened beverages among U.S. adults and teens, 2007-2013

The objective of this study was to estimate disparities in exposure to television advertising of sugar-sweetened and non-nutritive sweetened beverages among U.S. adults and teens. Data (2007-2013) came from the National Consumer Survey and included 115,510 adult respondents (age 18+) and 8635 teen respondents (age 12-17). The data was originally accessed in 2018 and analyzed in 2019-2020. The main outcomes were individual-level estimated exposure to advertisements for regular soda, diet soda, and energy/sport drinks. The main exposures were by race/ethnicity, household income, and educational attainment. Non-white adults (teens) were exposed to an estimated (per year) 101.5 (190.1) regular soda ads, 49.5 (61.2) diet soda ads, and 157.1 (279.6) energy/sport ads per year while white respondents were exposed to 97.5 (127.7) regular soda ads, 45.8 (44.2) diet soda ads, and 123.9 (192.0) energy/sport ads per year. Adult (teen) respondents who were non-white with low incomes and with low educational attainment were exposed to 4.7% (53.7%) more regular soda ads, 6.6% (43.8%) more diet ads, and 23.2% (56.2%) more energy/sport ads than respondents who were white with high incomes and high educational attainment. Demographic and socio-economic groups with a higher prevalence of obesity were exposed to significantly more advertisements for sugar-sweetened beverages. When evaluating potential policies to regulate marketing of sugar-sweetened and non-nutritive sweetened beverages, policymakers should consider the disparate exposure of at-risk populations to advertising of sugar-sweetened and non-nutritive sweetened beverages.

Obesity and Sex-Related Associations With Differential Effects of Sucralose vs Sucrose on Appetite and Reward Processing: A Randomized Crossover Trial

IMPORTANCE

Nonnutritive sweeteners (NNSs) are used as an alternative to nutritive sweeteners to quench desire for sweets while reducing caloric intake. However, studies have shown mixed results concerning the effects of NNSs on appetite, and the associations between sex and obesity with reward and appetitive responses to NNS compared with nutritive sugar are unknown.

OBJECTIVE

To examine neural reactivity to different types of high-calorie food cues (ie, sweet and savory), metabolic responses, and eating behavior following consumption of sucralose (NNS) vs sucrose (nutritive sugar) among healthy young adults.

DESIGN, SETTING, AND PARTICIPANTS

In a randomized, within-participant, crossover trial including 3 separate visits, participants underwent a functional magnetic resonance imaging task measuring blood oxygen level-dependent signal in response to visual cues. For each study visit, participants arrived at the Dornsife Cognitive Neuroimaging Center of University of Southern California at approximately 8:00 am after a 12-hour overnight fast. Blood was sampled at baseline and 10, 35, and 120 minutes after participants received a drink containing sucrose, sucralose, or water to measure plasma glucose, insulin, glucagon-like peptide(7-36), acyl-ghrelin, total peptide YY, and leptin. Participants were then presented with an ad libitum meal. Participants were right-handed, nonsmokers, weight-stable for at least 3 months before the study visits, nondieters, not taking medication, and with no history of eating disorders, illicit drug use, or medical diagnoses. Data analysis was performed from March 2020 to March 2021.

INTERVENTIONS

Participants ingested 300-mL drinks containing either sucrose (75 g), sucralose (individually sweetness matched), or water (as a control).

MAIN OUTCOMES AND MEASURES

Primary outcomes of interest were the effects of body mass index (BMI) status and sex on blood oxygen level-dependent signal to high-calorie food cues, endocrine, and feeding responses following sucralose vs sucrose consumption. Secondary outcomes included neural, endocrine, and feeding responses following sucrose vs water and sucralose vs water (control) consumption, and cue-induced appetite ratings following sucralose vs sucrose (and vs water).

RESULTS

A total of 76 participants were randomized, but 2 dropped out, leaving 74 adults (43 women [58%]; mean [SD] age, 23.40 [3.96] years; BMI range, 19.18-40.27) who completed the study. In this crossover design, 73 participants each received water (drink 1) and sucrose (drink 2), and 72 participants received water (drink 1), sucrose (drink 2), and sucralose (drink 3). Sucrose vs sucralose was associated with greater production of circulating glucose, insulin, and glucagon-like peptide-1 and suppression of acyl-ghrelin, but no differences were found for peptide YY or leptin. BMI status by drink interactions were observed in the medial frontal cortex (MFC; P for interaction < .001) and orbitofrontal cortex (OFC; P for interaction = .002). Individuals with obesity (MFC, β, 0.60; 95% CI, 0.38 to 0.83; P < .001; OFC, β, 0.27; 95% CI, 0.11 to 0.43; P = .002), but not those with overweight (MFC, β, 0.02; 95% CI, -0.19 to 0.23; P = .87; OFC, β, -0.06; 95% CI, -0.21 to 0.09; P = .41) or healthy weight (MFC, β, -0.13; 95% CI, -0.34 to 0.07; P = .21; OFC, β, -0.08; 95% CI, -0.23 to 0.06; P = .16), exhibited greater responsivity in the MFC and OFC to savory food cues after sucralose vs sucrose. Sex by drink interactions were observed in the MFC (P for interaction = .03) and OFC (P for interaction = .03) after consumption of sucralose vs sucrose. Female participants had greater MFC and OFC responses to food cues (MFC high-calorie vs low-calorie cues, β, 0.21; 95% CI, 0.05 to 0.37; P = .01; MFC sweet vs nonfood cues, β, 0.22; 95% CI, 0.02 to 0.42; P = .03; OFC food vs nonfood cues, β, 0.12; 95% CI, 0.02 to 0.22; P = .03; and OFC sweet vs nonfood cues, β, 0.15; 95% CI, 0.03 to 0.27; P = .01), but male participants' responses did not differ (MFC high-calorie vs low-calorie cues, β, 0.01; 95% CI, -0.19 to 0.21; P = .90; MFC sweet vs nonfood cues, β, -0.04; 95% CI, -0.26 to 0.18; P = .69; OFC food vs nonfood cues, β, -0.08; 95% CI, -0.24 to 0.08; P = .32; OFC sweet vs nonfood cues, β, -0.11; 95% CI, -0.31 to 0.09; P = .31). A sex by drink interaction on total calories consumed during the buffet meal was observed (P for interaction = .03). Female participants consumed greater total calories (β, 1.73; 95% CI, 0.38 to 3.08; P = .01), whereas caloric intake did not differ in male participants (β, 0.68; 95% CI, -0.99 to 2.35; P = .42) after sucralose vs sucrose ingestion.

CONCLUSIONS AND RELEVANCE

These findings suggest that female individuals and those with obesity may be particularly sensitive to disparate neural responsivity elicited by sucralose compared with sucrose consumption.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02945475.

Drinking Non-nutritive Sweetness Solution of Sodium Saccharin or Rebaudioside a for Guinea Pigs: Influence on Histologic Change and Expression of Sweet Taste Receptors in Testis and Epididymis

Saccharin sodium and rebaudioside A are extensively used as non-nutritive sweeteners (NNSs) in daily life. NNSs elicit a multitude of endocrine influences on animals, differing across species and chemically distinct sweeteners, whose exposure induce activation of sweet taste receptors in oral and extra-oral tissues with consequences of metabolic changes. To evaluate the influence of NNSs on histologic change and expression of sweet taste receptors in testis and epididymis of young male guinea pigs, thirty 4-week-old male guinea pigs with body weight 245.73 ± 6.02 g were randomly divided into five groups (n = 6) and received normal water (control group) and equivalent sweetness low dose or high dose of sodium saccharin (L-SS, 1.5 mM or H-SS, 7.5 mM) or rebaudioside A (L-RA, 0.5 mM or H-RA, 2.5 mM) solution for 28 consecutive days. The results showed that the relative testis weight in male guinea pig with age of 56 days represented no significant difference among all groups; in spite of heavier body weight in L-SS and H-RA, NNS contributes no significant influence on serum testosterone and estradiol level. Low-dose 0.5 mM rebaudioside A enhanced testicular and epididymal functions by elevating the expressions of taste receptor 1 subunit 2 (T1R2) and gustducin α-subunit (GNAT3), and high-dose 7.5 mM sodium saccharin exerted adverse morphologic influences on testis and epididymis with no effect on the expression of T1R2, taste receptor 1 subunit 2 (T1R3), and GNAT3. In conclusion, these findings suggest that a high dose of sodium saccharin has potential adverse biologic effects on the testes and epididymis, while rebaudioside A is a potential steroidogenic sweetener for enhancing reproductive functions.

Development of tropical mixed juice with low added-sugar content: Sensory and nutritional aspects

The aim of the present study was to develop a mixed tropical fruit juice of cashew apple, acerola and melon with low added-sugar content considering sensory and nutritional aspects. Five formulations were developed varying the concentration of the different fruits. A total of 172 consumers rated their overall liking using a 9-point hedonic scale and described their sensory characteristics using a Check-all-that-apply question. In addition, the functional properties of the juices were evaluated by analyzing vitamin C, total phenolic compounds and antioxidant capacity. Results showed that the addition of sugar and fruit composition affected the sensory characteristics and consumer liking of the formulations. Samples without added sugar and with higher melon concentration showed lower liking scores (p < 0.05). In addition, the highest concentration of acerola had a positive effect on nutritional characteristics. The formulation with 50% of fruit pulp (60% of cashew apple, 30% of acerola and 10% of melon), 47% of water, and 3% of added sugar achieved the best results. The effect of aroma on sweetness perception was investigated by adding identical to natural aromas of melon, apple and pineapple to the selected formulation. However, aroma did not significantly modify sweetness perception, evaluated using a rate-all-that-apply question.

Perceived Healthiness of Sweeteners among Young Adults in Canada

Purpose: To compare the perceived healthiness of different sweeteners relative to table sugar and examine efforts to consume less sugars and sweeteners.Methods: As part of the 2017 Canada Food Study online survey, 1000 youth and young adults were randomized to rate the healthiness of 1 of 6 sweeteners (aspartame, sucralose, stevia, agave, high-fructose corn syrup, "raw" sugar) or 1 sweetener brand name (Splenda) compared with "table sugar".Results: Perceptions of sweeteners varied widely. For example, the majority of respondents perceived high-fructose corn syrup (63.9%) and aspartame (52.4%) as less healthy than table sugar, whereas almost half (47.8%) perceived raw sugar as being healthier than table sugar. No assessed socio-demographic variables were significantly associated with perceived healthiness of sweeteners compared with table sugar (P ≥ 0.05). More consumers had attempted to consume less sugar (65.4%) compared with less "artificial" (31.2%) or "natural" (24.0%) low-calorie sweeteners.Conclusions: Perceptions of sweetener healthiness may be related to sweeteners' perceived level of "naturalness" rather than energy content. This has important implications for understanding consumer preferences, particularly given greater use of low-calorie sweeteners in the food supply and policy developments such as sugar taxes and enhanced sugar labelling.

Effects of Oro-Sensory Exposure on Satiation and Underlying Neurophysiological Mechanisms-What Do We Know So Far?

The mouth is the first part of the gastrointestinal tract. During mastication sensory signals from the mouth, so-called oro-sensory exposure, elicit physiological signals that affect satiation and food intake. It has been established that a longer duration of oro-sensory exposure leads to earlier satiation. In addition, foods with more intense sweet or salty taste induce earlier satiation compared to foods that are equally palatable, but with lower taste intensity. Oro-sensory exposure to food affects satiation by direct signaling via the brainstem to higher cortical regions involved in taste and reward, including the nucleus accumbens and the insula. There is little evidence that oro-sensory exposure affects satiation indirectly through either hormone responses or gastric signals. Critical brain areas for satiation, such as the brainstem, should be studied more intensively to better understand the neurophysiological mechanisms underlying the process of satiation. Furthermore, it is essential to increase the understanding of how of highly automated eating behaviors, such as oral processing and eating rate, are formed during early childhood. A better understanding of the aforementioned mechanisms provides fundamental insight in relation to strategies to prevent overconsumption and the development of obesity in future generations.

Sugary drink advertising expenditure across Australian media channels 2016-2018

OBJECTIVE

The aim of this study was to describe advertising expenditure for sugary drinks compared with alternative cold non-alcoholic beverages (artificially sweetened beverages, plain water, plain milk) between 2016 and 2018 across Australian media channels.

METHODS

Monthly estimates of advertising expenditure for non-alcoholic beverages were obtained from Nielsen Media and aggregated by product type and media.

RESULTS

Total sugary drink advertising expenditure between 2016 and 2018 ($129.5M) significantly exceeded expenditure on artificially sweetened drinks ($23.26M), plain water ($14.27M), and plain milk ($31.30M). Television and out-of-home advertising accounted for the largest share of sugary drink advertising (45%, 35%). Expenditure on out-of-home advertising was more heavily dominated by sugary drinks (75%) than advertising in all media combined (65%). Sugary drink advertising peaked in warmer months and was lowest in August. Soft drinks (26%), flavoured milks (24%) and energy drinks (21%) accounted for the majority of sugary drink advertising.

CONCLUSIONS

Cold non-alcoholic beverage advertising in Australian media is dominated by the advertising of sugary drinks. Implications for public health: Restricting unhealthy beverage advertising on television and out-of-home media may be most effective initially. However, comprehensive restrictions capturing a broader range of media and settings would be optimal to prevent displacement and limit advertising reach and exposure.

SODA MAPS: A Framework for Understanding Caffeinated Sugary Drink Consumption Among Children

Excess sugary drink (SD) consumption is associated with childhood obesity and development of cardiometabolic disease. In addition to having high added sugar content, many SDs also contain caffeine, which may further encourage excess SD consumption among children. The objective of this study was to develop a conceptual framework of children's caffeinated SD consumption using group concept mapping, an applied social research multimethodology that collectively harnesses qualitative and quantitative data from participants to generate a visual representation of their ideas and input. Children, 8–14 years old, who reported consuming ≥12 ounces of caffeinated SDs (e.g., sodas, sweet teas) per day were recruited throughout Washington, D.C. and invited to participate. Concept mapping included three participant-driven activities: (1) brainstorming (n = 51), during which children reported reasons for their SD consumption, from which 58 unique reasons were identified; (2) sorting (n = 70), during which children sorted each of the reported reasons into categories and named each category; and (3) rating (n = 74), during which children rated the influence of each reason on their own caffeinated SD consumption. Similarity matrices, multidimensional scaling, and hierarchical cluster analysis were used to generate concept maps (hereafter “SODA MAPS”), which display the 58 reasons organized within eight overarching clusters. Among these eight clusters, Taste and Feel, Something to Do, and Energy were rated as particularly influential. Children's caffeinated SD consumption is encouraged not only by the palatable taste and reported preferences for these beverages (e.g., Taste and Feel), but also by psychological (e.g., Mood and Focus), biological (e.g., Energy), social (e.g., Something to Do) and environmental reasons (e.g., Nothing Better Available). Thus, the SODA MAPS can inform the development of tailored, multi-level SD reduction interventions that incorporate strategies to address important and currently overlooked reasons for caffeinated SD consumption among children.

The impact of nutritive and non-nutritive sweeteners on the central nervous system: preliminary study

BACKGROUND

Human consumption of food and beverages containing added nutritive or non-nutritive sweeteners has increased worldwide.

OBJECTIVE

The present study evaluated the possible impact of frequent sweetener consumption on human CNS activity and functions through neuropsychological testing and EEG/qEEG analysis.

METHODS

A sample of 23 women and 16 men, aged 18-35, with a body mass index between 18 and 24.9 kg/m² was evaluated. Participants underwent a 1-week washout period in which food with added sugars or sweeteners was restricted from their diet. Initial assessment of cognitive functions was performed with a validated neuropsychological test and EEG/qEEG analysis, prior to supplementation. Sucrose, sucralose, or steviol glycosides, in commercially available presentations, were randomly assigned to three experimental groups of 13 participants each. Sweeteners were supplemented in fixed amounts, daily, for six weeks. After supplementation, neurological tests were repeated and the initial and final results were compared.

RESULTS

The results show no significant changes between final and initial measures in the steviol glycosides group. However, a significant decrease in encoding memory was found in the sucrose group in the final evaluation. Strikingly, the sucralose group showed a significant decrease in overall memory, encoding memory, and executive functions after supplementation. Furthermore, qEEG analysis showed an increase in theta wave absolute and relative power at the final evaluation in the same group.

CONCLUSION

These data show that frequent consumption of specific sweeteners is accompanied by measurable changes in EEG/qEEG activity and neuropsychological test performance in humans.

Soft drinks and sweeteners intake: Possible contribution to the development of metabolic syndrome and cardiovascular diseases. Beneficial or detrimental action of alternative sweeteners?

The rapid increase in obesity, metabolic syndrome, and cardiovascular diseases (CVDs) has been related to the rise in sugar-added foods and sweetened beverages consumption. An interesting approach has been to replace sugar with alternative sweeteners (AS), due to their impact on public health. Preclinical and clinical studies, which analyze the safety of AS intake, are still limited. Major pathogenic mechanisms of these substances include ROS and AGEs formation. Indeed, endothelial dysfunction involving in the pathogenesis of micro- and macro-vascular diseases is mitochondrial dysfunction dependent. Hyperglycemia and endoplasmic reticulum stress together produce ROS, contributing to the development and progression of cardiovascular complications during type 2 diabetes (T2D), thus causing oxidative changes and direct damage of lipids, proteins, and DNA. Epidemiological studies in healthy subjects have suggested that the consumption of artificial AS can promote CV complications, such as glucose intolerance and predisposition to the onset of T2D, whereas natural AS could reduce hyperglycemia, improve lipid metabolism and have antioxidant effects. Long-term prospective clinical randomized studies are needed to evaluate precisely whether exposure to alternative sugars can have clinical implications on natural history and clinical outcomes, especially in children or during the gestational period through breast milk.

Acute diet soda consumption alters brain responses to food cues in humans: A randomized, controlled, cross-over pilot study

BACKGROUND

Diet soda consumption has frequently been linked to obesity and its comorbidities in epidemiological studies. Whether this link is causal and a potential mechanism remains to be determined.

AIM/METHODS

This randomized, cross-over, controlled pilot study sought to determine whether there may be changes in reward-related brain activations to visual food cues after acute consumption of diet soda versus regular soda or carbonated water using functional magnetic resonance imaging.

RESULTS

Diet soda as compared to carbonated water consumption increased activation of reward-related caudate to highly versus less desirable food cues. Diet soda as compared to regular soda increased reward-related insula and decreased activation of cognitive control-related dorsolateral prefrontal cortex to food cues versus non-food cues. No changes in ratings of hunger an hour after beverage consumption were observed.

CONCLUSIONS

These results may suggest a potential mechanism for diet soda to increase food palatability through activation of the reward system and suppression of inhibitory control that remains to be confirmed by future studies.

Strategies for Reducing Salt and Sugar Intakes in Individuals at Increased Cardiometabolic Risk

Non-communicable diseases (NCDs) are the first causes of death worldwide. Reduction in the dietary intake of salt and sugars is important lifestyle advice that is useful for NCD prevention. However, the simple recommendations of reducing salt and sugars by healthcare professionals are often ineffective; innovative strategies are therefore necessary. This review aimed at describing the current knowledge about the strategies to reduce dietary salt and sugar intake, including both strategies for the food industry to reduce the salt or sugar of its products and recommendations for health professionals in a clinical context, such as the replacement with substitutes in foods, the gradual reduction to allow a progressive consumer adaptation towards less intense taste, and the different spatial distribution of tastants within the food matrix with taste intensity enhancement. In addition, the cross-modal interaction between two or more different sensory modalities as an innovative strategy for enhancing sweetness and saltiness perception was described. Finally, the dietary tips for salt and sugar reduction were summarized in order to create a comprehensive guide of dietary advices for healthcare professionals for optimizing the management of patients at increased cardiometabolic risk.

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.

Miracle Berry as a Potential Supplement in the Control of Metabolic Risk Factors in Cancer

The increased incidence of chronic diseases related to altered metabolism has become a social and medical concern worldwide. Cancer is a chronic and multifactorial disease for which, together with genetic factors, environmental factors are crucial. According to the World Health Organization (WHO), up to one third of cancer-related deaths could be prevented by modifying risk factors associated with lifestyle, including diet and exercise. Obesity increases the risk of cancer due to the promotion of low-grade chronic inflammation and systemic metabolic oxidative stress. The effective control of metabolic parameters, for example, controlling glucose, lipid levels, and blood pressure, and maintaining a low grade of chronic inflammation and oxidative stress might represent a specific and mechanistic approach against cancer initiation and progression. Miracle berry (MB) (Synsepalum dulcificum) is an indigenous fruit whose small, ellipsoid, and bright red berries have been described to transform a sour taste into a sweet one. MB is rich in terpenoids, phenolic compounds, and flavonoids, which are responsible for their described antioxidant activities. Moreover, MB has been reported to ameliorate insulin resistance and inhibit cancer cell proliferation and malignant transformation in vitro. Herein, we briefly summarize the current knowledge of MB to provide a scientific basis for its potential use as a supplement in the management of chronic diseases related to altered metabolism, including obesity and insulin resistance, which are well-known risk factors in cancer. First, we introduce cancer as a metabolic disease, highlighting the impact of systemic metabolic alterations, such as obesity and insulin resistance, in cancer initiation and progression. Next, as oxidative stress is closely associated with metabolic stress, we also evaluate the effect of phytochemicals in managing oxidative stress and its relationship with cancer. Finally, we summarize the main biological activities described for MB-derived extracts with a special focus on the ability of miraculin to transform a sour taste into a sweet one through its interaction with the sweet taste receptors. The identification of sweet taste receptors at the gastrointestinal level, with effects on the secretion of enterohormones, may provide an additional tool for managing chronic diseases, including cancer.

Impact of Steviol Glycosides and Erythritol on the Human and Cebus apella Gut Microbiome

Leaf extracts of Stevia rebaudiana, composed of more than 10 steviol glycosides (SGs), are used as non-nutritive, table sugar (sucrose) alternatives due to their high level of sweetness and low caloric impact. They are often combined with the sugar alcohol erythritol to increase volume and reduce aftertaste. Little is known of the impact of sugar alternatives on the human gut microbiota in terms of the diversity, composition, and metabolic products. Testing of SGs and erythritol using six representatives of the gut microbiota in vitro found no impact on bacterial growth, yet treatment with erythritol resulted in an enhancement of butyric and pentanoic acid production when tested using a human gut microbial community. Furthermore, administration of SGs and erythritol to a Cebus apella model resulted in changes to the gut microbial structure and diversity. Overall, the study did not find a negative impact of SGs and erythritol on the gut microbial community.

What was First, Obesity or Inflammatory Bowel Disease? What Does the Gut Microbiota Have to Do with It?

A sedentary lifestyle and inadequate nutrition often leads to disturbances in intestinal homeostasis, which may predispose people to excess body weight and metabolic syndrome. Obesity is frequently observed in patients with inflammatory bowel diseases (IBD), similar to the general population. Obesity may exert a negative effect on the course of IBD as well as reduce the response to treatment. Moreover, it may also be an additional risk factor for vein thromboembolism during the flare. In both obesity and IBD, it is of great importance to implement proper dietary ingredients that exert desirable effect on gut microbiota. The key to reducing body mass index (BMI) and alleviating the course of IBD is preserving healthy intestinal microflora.

Acute glycemic and insulinemic effects of low-energy sweeteners: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

It has been suggested that low-energy sweeteners (LES) may be associated with an increased risk of metabolic diseases, possibly due to stimulation of glucose-responsive mechanisms.

OBJECTIVE

We conducted a systematic review and meta-analysis of human intervention studies examining the acute effect of LES intake on postprandial glucose (PPG) and postprandial insulin (PPI) responses, in order to comprehensively and objectively quantify these relations.

METHODS

We systematically searched the Medline, OVID FSTA, and SCOPUS databases until January 2020. Randomized controlled trials comparing acute postprandial effects on PPG and/or PPI after exposure to LES, either alone, with a meal, or with other nutrient-containing preloads to the same intervention without LES were eligible for inclusion. PPG and PPI responses were calculated as mean incremental area under the curve divided by time. Meta-analyses were performed using random effects models with inverse variance weighing.

RESULTS

Twenty-six papers (34 PPG trials and 29 PPI trials) were included. There were no reports of statistically significant differences in the effects of LES on PPG and PPI responses compared with control interventions. Pooled effects of LES intake on the mean change difference in PPG and PPI were -0.02 mmol/L (95% CI: -0.09, 0.05) and -2.39 pmol/L (95% CI: -11.83, 7.05), respectively. The results did not appreciably differ by the type or dose of LES consumed, cointervention type, or fasting glucose and insulin levels. Among patients with type 2 diabetes, the mean change difference indicated a smaller PPG response after exposure to LES compared with the control (-0.3 mmol/L; 95% CI: -0.53, -0.07).

CONCLUSIONS

Ingestion of LES, administered alone or in combination with a nutrient-containing preload, has no acute effects on the mean change in postprandial glycemic or insulinemic responses compared with a control intervention. Apart from a small beneficial effect on PPG (-0.3 mmol/L) in studies enrolling patients with type 2 diabetes, the effects did not differ by type or dose of LES, or fasting glucose or insulin levels. This review and meta-analysis was registered at PROSPERO as CRD42018099608.

Comparative effects of commonly used commercially available non-nutritive sweeteners on diabetes-related parameters in non-diabetic rats

Studies of non-nutritive sweeteners (NNS) in diabetes models have been limited to their pure forms or NNS-sweetened products. Hence, we conducted a comparative study on the effects of commercial table-top NNS on diabetes-related parameters in non-diabetic rats. Normal animals were fed for 5 weeks with aqueous solutions of aspartame-, sucralose-, stevia-, sodium cyclamate- and saccharin-based commercial NNS at concentrations equivalent to the sweetness of 10% sucrose solution and thereafter food intake, blood glucose, lipid profile, and biochemical parameters were measured. Aspartame adversely affected blood cholesterols, while cyclamate increased food intake and weight gain. Stevia reduced weight gain and exhibited insulinotropic effects. These data in normal rats hypothetically suggest that stevia-based NNS may help in glycemic control and body weight management, while cyclamate- and aspartame-based NNS may increase body weight and risk of cardiovascular diseases. Further clinical studies are, however, required to confirm the results of this study. PRACTICAL APPLICATIONS: The use of NNS is becoming more popular, especially for individuals with diabetes. However, while there are several commercial table-top NNS available in the market, little is known about how they affect most diabetes-related parameters of consumers, as most of the previous studies on NNS have been limited to their pure forms or NNS-sweetened products. Therefore, we comparatively studied the effects of some commercially available table-top forms of the different NNS (aspartame, sucralose, cyclamate, saccharin, and stevia) on diabetes-related parameters in normal rats. These findings in normal rats suggested that some commercially available NNSs like stevia-based NNS may be suitable for glycemic control and body weight management, while cyclamate- and aspartame-based NNS may increase body weight and risk of cardiovascular diseases. However, these finding in normal rats is subject to additional corroborative clinical studies.

Neuroendocrine and Metabolic Effects of Low-Calorie and Non-Calorie Sweeteners

Since excessive sugar consumption has been related to the development of chronic metabolic diseases prevalent in the western world, the use of sweeteners has gradually increased worldwide over the last few years. Although low- and non-calorie sweeteners may represent a valuable tool to reduce calorie intake and prevent weight gain, studies investigating the safety and efficacy of these compounds in the short- and long-term period are scarce and controversial. Therefore, future studies will need to elucidate the potential beneficial and/or detrimental effects of different types of sweeteners on metabolic health (energy balance, appetite, body weight, cardiometabolic risk factors) in healthy subjects and patients with diabetes, obesity and metabolic syndrome. In this regard, the impact of different sweeteners on central nervous system, gut hormones and gut microbiota is important, given the strong implications that changes in such systems may have for human health. The aim of this narrative review is to summarize the current evidence for the neuroendocrine and metabolic effects of sweeteners, as well as their impact on gut microbiota. Finally, we briefly discuss the advantages of the use of sweeteners in the context of very-low calorie ketogenic diets.

Intense Sweeteners, Taste Receptors and the Gut Microbiome: A Metabolic Health Perspective

Intense sweeteners (IS) are often marketed as a healthier alternative to sugars, with the potential to aid in combating the worldwide rise of diabetes and obesity. However, their use has been counterintuitively associated with impaired glucose homeostasis, weight gain and altered gut microbiota. The nature of these associations, and the mechanisms responsible, are yet to be fully elucidated. Differences in their interaction with taste receptors may be a potential explanatory factor. Like sugars, IS stimulate sweet taste receptors, but due to their diverse structures, some are also able to stimulate bitter taste receptors. These receptors are expressed in the oral cavity and extra-orally, including throughout the gastrointestinal tract. They are involved in the modulation of appetite, glucose homeostasis and gut motility. Therefore, taste genotypes resulting in functional receptor changes and altered receptor expression levels may be associated with metabolic conditions. IS and taste receptors may both interact with the gastrointestinal microbiome, and their interactions may potentially explain the relationship between IS use, obesity and metabolic outcomes. While these elements are often studied in isolation, the potential interactions remain unexplored. Here, the current evidence of the relationship between IS use, obesity and metabolic outcomes is presented, and the potential roles for interactions with taste receptors and the gastrointestinal microbiota in modulating these relationships are explored.

Low Calorie Sweeteners Differ in Their Physiological Effects in Humans

Low calorie sweeteners (LCS) are prevalent in the food supply for their primary functional property of providing sweetness with little or no energy. Though tested for safety individually, there has been extremely limited work on the efficacy of each LCS. It is commonly assumed all LCS act similarly in their behavioral and physiological effects. However, each LCS has its own chemical structure that influences its metabolism, making each LCS unique in its potential effects on body weight, energy intake, and appetite. LCS may have different behavioral and physiological effects mediated at the sweet taste receptor, in brain activation, with gut hormones, at the microbiota and on appetitive responses. Further elucidation of the unique effects of the different commercially available LCS may hold important implications for recommendations about their use for different health outcomes.

Changes in nutrient and calorie intake, adipose mass, triglycerides and TNF-α concentrations after non-caloric sweetener intake: A pilot study

Establishing the safety of non-caloric sweetener consumption in humans is a difficult task, since many contradictory results have been reported. The objective of this study was to compare the effect of frequent intake of sucrose, sucralose or steviol glycosides, on selected anthropometric, biochemical and immunological parameters in healthy, young adults. 38 individuals with normal body mass index were recruited and randomly divided into three experimental groups. After a washout week (where food with added sweeteners was restricted), each group was supplemented with sucrose (8 × 5 g packets/day), sucralose or steviol glycosides (4 × 1 g packets/day each) for 6 weeks. Selected variables were measured before and after treatment in each group and differences within and among groups were assessed. Our results showed that, compared to baseline, there was a modest but significant increase in weight (p = 0.0293) in the sucralose group, while the steviol glycosides group reduced their fat mass (p = 0.0390). No differences were observed in glycaemia; however, there was a significant increase in serum triglycerides (77.8-110.8 mg/dL) and cholesterol (162.0-172.3 mg/dL) in the sucrose group, whereas the steviol glycosides group presented lower triglycerides (104.7-92.8 mg/dL) and TNF-α concentrations (51.1-47.5 pg/mL). Comparison among groups showed differences in serum triglycerides (p = 0.0226), TNF-α (p = 0.0460) and IL-β (p = 0.0008). Our results suggest that, even in a short time span, frequent intake of steviol glycosides may have positive effects on metabolic parameters that may be relevant for human health.

Low-calorie sweeteners augment tissue-specific insulin sensitivity in a large animal model of obesity

PURPOSES

Whether low-calorie sweeteners (LCS), such as sucralose and acesulfame K, can alter glucose metabolism is uncertain, particularly given the inconsistent observations relating to insulin resistance in recent human trials. We hypothesized that these discrepancies are accounted for by the surrogate tools used to evaluate insulin resistance and that PET ¹⁸FDG, given its capacity to quantify insulin sensitivity in individual organs, would be more sensitive in identifying changes in glucose metabolism. Accordingly, we performed a comprehensive evaluation of the effects of LCS on whole-body and organ-specific glucose uptake and insulin sensitivity in a large animal model of morbid obesity.

METHODS

Twenty mini-pigs with morbid obesity were fed an obesogenic diet enriched with LCS (sucralose 1 mg/kg/day and acesulfame K 0.5 mg/kg/day, LCS diet group), or without LCS (control group), for 3 months. Glucose uptake and insulin sensitivity were determined for the duodenum, liver, skeletal muscle, adipose tissue and brain using dynamic PET ¹⁸FDG scanning together with direct measurement of arterial input function. Body composition was also measured using CT imaging and energy metabolism quantified with indirect calorimetry.

RESULTS

The LCS diet increased subcutaneous abdominal fat by ≈ 20% without causing weight gain, and reduced insulin clearance by ≈ 40%, while whole-body glucose uptake and insulin sensitivity were unchanged. In contrast, glucose uptake in the duodenum, liver and brain increased by 57, 66 and 29% relative to the control diet group (P < 0.05 for all), while insulin sensitivity increased by 53, 55 and 28% (P < 0.05 for all), respectively. In the brain, glucose uptake increased significantly only in the frontal cortex, associated with improved metabolic connectivity towards the hippocampus and the amygdala.

CONCLUSIONS

In miniature pigs, the combination of sucralose and acesulfame K is biologically active. While not affecting whole-body insulin resistance, it increases insulin sensitivity and glucose uptake in specific tissues, mimicking the effects of obesity in the adipose tissue and in the brain.

Effects of different sweeteners on behavior and neurotransmitters release in mice

Four natural sweeteners (sucrose, stevioside, maltose and xylitol) and six artificial sweeteners (acesulfame, sucralose, aspartame, cyclamate, saccharin and neotame) were used to study the effects of different sweeteners on the behavior and neurotransmitter release of mice with two-bottle preference experiments. The results showed that very significant preference behavior for 8% sucrose solution, 0.3% stevioside solution, 10 mM acesulfame, 10 mM sucralose and 10 mM aspartame solutions (p < 0.01) was observed on mice. Long-term exposure of sucrose solution and acesulfame solution can affect the behavioral indicators such as solution consumption, feed intake, body weight and the release of neurotransmitters in mice. The solution consumption and the release of neurotransmitters were significantly greater (p < 0.05) than that of the control group (water group), but there was no significant difference in feed intake. The acesulfame-A and acesulfame-B groups had no significant difference on the consumption of solution and feed intake, but there was significant difference in the release of neurotransmitters. The result also showed that different sweetener solutions with similar sweetness had the same effect on the neurotransmitters release, and it can be inferred that mice have an addictive behavioral characteristic to sucrose.

A prospective study of artificially sweetened beverage intake and cardiometabolic health among women at high risk

BACKGROUND

Artificially sweetened beverages (ASBs) are commonly consumed and recommended for individuals at high risk for cardiometabolic diseases; however, the health effects of ASBs remain contradictory. Given that cross-sectional analyses are subject to reverse causation, prospective studies with long-term follow-up are needed to evaluate associations between ASBs and cardiometabolic health, especially among high-risk individuals.

OBJECTIVE

The aim of this study was to examine associations of ASB intake and cardiometabolic health among high-risk women with prior gestational diabetes mellitus (GDM).

METHODS

We included 607 women with GDM from the Danish National Birth Cohort (DNBC; 1996-2002) who completed a clinical exam 9-16 y after the DNBC pregnancy for the Diabetes & Women's Health (DWH) Study (2012-2014). We assessed ASB intake using FFQs completed during the DNBC pregnancy and at the DWH Study clinical exam. We examined cardiometabolic outcomes at the DWH clinical exam. We estimated percentage differences in continuous cardiometabolic markers and RRs for clinical endpoints in association with ASB intake both during pregnancy and at follow-up adjusted for prepregnancy BMI, diet, and lifestyle factors. Sensitivity analyses to account for reverse causation were performed.

RESULTS

In pregnancy and at follow-up, 30.4% and 36.4% of women regularly (≥2 servings/wk) consumed ASB, respectively. Consumption of ASBs, both during pregnancy and at follow-up, was associated with higher glycated hemoglobin (HbA1c), insulin, HOMA-IR, triglycerides, liver fat, and adiposity and with lower HDL at follow-up. After adjustment for covariates, particularly prepregnancy BMI, the majority of associations between ASB intake in pregnancy and outcomes at follow-up became null with the exception of HbA1c. ASB intake at follow-up (≥1 serving/d compared with <1 serving/mo) was associated with higher HbA1c (6.5%; 95% CI: 1.9, 11.3; P-trend = 0.007); however, associations were not upheld in sensitivity analyses for reverse causation.

CONCLUSIONS

Among Danish women with a history of GDM, ASB intake was not significantly associated with cardiometabolic profiles.

Oral and Systemic Effects of Xylitol Consumption

Recent results of randomized trials testing the efficacy of xylitol in caries prevention have been conflicting. This narrative review reveals the sources of discrepancy. The following databases were searched for the terms "xylitol" or "artificial sweeteners" restricted to the English language: PubMed, Web of Science, Evidenced-Based Medicine, Scopus, and the Cochrane database. In a separate search, the terms "dental caries" or "cariogenicity" or "glucosyltransferase" or "low glycemic" or "low insulinemic" or "dysbiosis" or "gut microbiome" were used and then combined. In section I, findings regarding the role of xylitol in dental caries prevention, the appropriateness of research methods, and the causes for potential biases are summarized. In section II, the systemic effects of xylitol on gut microbiota as well as low-glycemic/insulinogenic systemic effects are evaluated and summarized. The substitution of a carbonyl group with an alcohol radical in xylitol hinders its absorption and slowly releases sugar into the bloodstream. This quality of xylitol is beneficial for diabetic patients to maintain a constant glucose level. Although this quality of xylitol has been proven in in vitro and animal studies, it has yet to be proven in humans. Paradoxically, recent animal studies reported hyperglycemia and intestinal dysbiosis with artificial sweetener consumption. Upon careful inspection of evidence, it was revealed that these reports may be due to misinterpretation of original references or flaws in study methodology. Any systemic benefits of xylitol intake must be weighed in consideration with the well-established adverse gastrointestinal consequences. The contribution of xylitol to gut dysbiosis that may affect systemic immunity warrants further research.

Simultaneous determination of three sulfanilamide artificial sweeteners in foodstuffs by capillary electrophoresis coupled with contactless conductivity detection based on porous aromatic frameworks enhanced solid phase extraction

In this paper, a simple and easy method of solid phase extraction (SPE) followed by capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D) is evaluated as a novel approach for the simultaneous determination of acesulfame-K (ACE), sodium saccharin (SAC), and sodium cyclamate (CYC) in foodstuffs without derivatization. To reduce the complex matrix interference resulting from the constituents of samples and enriched targets, porous aromatic frameworks (PAFs) enhanced SPE, a suitable sample pretreatment procedure, was introduced. Several factors affecting extraction efficiency and electrophoretic separation were investigated. Additionally, the interaction mechanisms between the host (PAF-6) and guests (ACE, SAC, and CYC) were studied. Under the optimum conditions, three sulfanilamide artificial sweeteners were baseline separated within 8 min, exhibiting a linear calibration over two orders of magnitude (R2 > 0.995). The limits of detection (LOD) and quantification (LOQ) were considered better than those usually obtained by CE with ultraviolet and C4D detection. The proposed SPE–CE–C4D method has been successfully applied to analyse beverage samples and candied fruits with recoveries in the range of 78.89%–92.00%.

Biomarker approaches to assessing intakes and health impacts of sweeteners: challenges and opportunities

The term 'sweeteners' encompasses both nutritive and non-nutritive sweeteners, which when added to food/beverages, can enhance the flavour and other functional properties of food/beverage products. This review considers how dietary biomarker approaches may enhance current understanding of nutritive sweetener (namely free sugars) and non-nutritive or low-energy sweetener (LES) intakes and how these may impact health. Recent public health strategies to reduce free sugar consumption will help contribute to challenging sugar intake targets. Robust evaluation is needed to determine the effectiveness of these approaches to reducing free sugar consumption. LES provides a sweet taste without the addition of appreciable energy and can help maintain the palatability of reformulated products. All LES undergo rigorous safety evaluations prior to approval for use. Whilst intervention data suggest LES can be beneficial for health (relating to weight status and glycaemic control), debate persists on their use and findings from population-based research are mixed, in part because of potential contributing factors such as reverse causality. Additionally, assessments often consider only certain sources of LES (e.g. LES-beverages) and/or LES as a homogeneous group despite differing biological fates, thus not adequately capturing intakes of individual LES or allowing for reliable estimation of overall intakes. Urinary biomarker approaches developed/investigated for sweetener consumption have the potential to overcome existing limitations of dietary data by providing more objective intake data, thereby enhancing population-based research. In conclusion, such biomarker approaches to the concomitant study of free sugars and LES intakes are timely and represent interesting developments in an area of significant public health interest.

SWEET MAPS: A Conceptualization of Low-Calorie Sweetener Consumption Among Young Adults

BACKGROUND

The extent to which low-calorie sweeteners (LCSs) are helpful or harmful for weight management and metabolic health is unclear, because LCS effects may depend on the context in which they are consumed.

OBJECTIVE

To develop a conceptual framework for LCS consumption.

METHODS

Young adults ages 18-35 y, who reported LCS consumption, were recruited from a private, urban, university in the mid-Atlantic United States. Concept mapping, a mixed-method approach was used to identify, organize, and quantify determinants of LCS consumption. First, participants (n = 68) identified reasons for their LCS consumption through brainstorming; content analysis of those reasons identified 37 specific determinants of LCS consumption. Second, participants (n = 93) sorted all 37 determinants conceptually. Third, participants (n = 97) rated the extent to which each of the 37 determinants was reflective of their own consumption. Similarity matrices, multidimensional scaling, and hierarchical cluster analysis produced a series of 2-dimensional concept maps (SWEET MAPS).

RESULTS

The SWEET MAPS identified 37 determinants, organized within 8 factors reflective of 3 overarching motives: perceived health benefits, palatability, and accessibility of LCSs. At the determinant level, the most highly rated determinants that exceeded the boundary (rating >3.0) were: "I want something that tastes sweet," "I am trying to maintain/control my weight," "They contain fewer calories," "They are available," and "I want to save calories because I am eating a high-calorie meal."

CONCLUSIONS

LCS consumption is a function of many inter-related determinants spanning biological, psychological, and social domains. The SWEET MAPS are an important and novel use of concept mapping methods that can be used to inform the design and interpretation of future studies evaluating LCS effects.

The acute effects of the non-nutritive sweeteners aspartame and acesulfame-K in UK diet cola on glycaemic response

Substituting sugar-sweetened for artificially sweetened beverages may reduce energy intakes. This study aims to ascertain the acute glycaemic effects of the NNS aspartame and acesulfame-K in UK diet-cola (DC). Ten healthy participants attended the laboratory fasted on three occasions. Individuals drank (1) 25 g glucose in 125 mL water + 236 mL water, (2) 25 g glucose in 125 mL water with 236 mL DC and (3) 236 mL sucrose-sweetened cola with 125 mL water. Blood (glucose) was measured pre-test and every 15 minutes over a 120-minute period using portable glucometers. The glucose-control and glucose + DC elicited similar blood glucose rises above pre-prandial levels. Sucrose-sweetened cola showed a non-significant lower rise in postprandial glycaemia, exhibiting the lowest glycaemic index (GI) (77.0 ± 9.1). GI of glucose (100.0 ± 15.2) and glucose + DC (104.3 ± 8.5) was similar and a one-way repeated-measures ANOVA showed no significant differences in glycaemic response between test drinks (F(2,29) = 1.68, p > .05). Results demonstrate the glycaemic inactivity of non-nutritive sweeteners.

Non-Nutritive Sweeteners and Their Implications on the Development of Metabolic Syndrome

Individuals widely use non-nutritive sweeteners (NNS) in attempts to lower their overall daily caloric intake, lose weight, and sustain a healthy diet. There are insufficient scientific data that support the safety of consuming NNS. However, recent studies have suggested that NNS consumption can induce gut microbiota dysbiosis and promote glucose intolerance in healthy individuals that may result in the development of type 2 diabetes mellitus (T2DM). This sequence of events may result in changes in the gut microbiota composition through microRNA (miRNA)-mediated changes. The mechanism(s) by which miRNAs alter gene expression of different bacterial species provides a link between the consumption of NNS and the development of metabolic changes. Another potential mechanism that connects NNS to metabolic changes is the molecular crosstalk between the insulin receptor (IR) and G protein-coupled receptors (GPCRs). Here, we aim to highlight the role of NNS in obesity and discuss IR-GPCR crosstalk and miRNA-mediated changes, in the manipulation of the gut microbiota composition and T2DM pathogenesis.

In search for an alternative to sugar to reduce obesity

Consumption of table sugar has been increasing despite the warnings of public health officials as to the potential adverse consequences of sugar consumption. The World Health Organization recommends restricting consumption of sugars to no more than 10% of daily caloric intake, with a proposal to lower this level to 5% or less for optimal health. Unfortunately substituting sugar with the currently available artificial sweeteners does not appear to have favorable clinical effects. Given the health-related concerns with the currently available sweeteners such as increased risk of obesity and type 2 diabetes there is renewed interest in identifying a safe and palatable sweetener. The sweet extracts of natural plants such as stevia and monk fruit as well as naturally occurring rare sugars have become attractive alternatives. Although most of the sweeteners are sugars, there are some proteins such as braziien and miraculin that have intense sweetness and are being developed as sweeteners. Several companies are pursuing the development of "bitterness-blockers" to remove flavor defects. Other novel approaches include coating mineral carriers with sugar or hollowing out the sugar crystals. Naturally occurring rare sugars such as D-allulose (D-psicose), D-tagatose, D-sorbose and D-allose are attractive sweeteners. They do have the bulk and the mouth fill of table sugar with reduced caloric content (0.2 kcal/g for D-allulose). Additional randomized controlled trials are necessary to define the long term safety and efficacy of these sugars.

Astrogliosis and decreased neural viability as consequences of early consumption of aspartame and acesulfame potassium in male Wistar rats

Artificial sweeteners are mainly used as substitutes for sucrose derivates. In this study, we analyzed if the chronic consumption of aspartame or acesulfame potassium at an early age, produces histological alterations, astrogliosis and decreased neuronal viability, in hippocampus, prefrontal cortex, amygdala and hypothalamus of male Wistar rats. A histological analysis was performed on male Wistar rats that consumed aspartame or acesulfame potassium during 90 days, initiating the consumption of sweeteners immediately after weaning. The evaluation of neuronal morphology in different areas of the brain was performed with hematoxylin - eosin staining. To measure astrogliosis and neuronal viability, we used the immunohistochemical technique, with the glial fibrillary acidic protein immunomodulators (GFAP) and with neuronal-specific enolase (NSE). The consumption of aspartame or acesulfame potassium promoted morphological changes of neurons including increased pyknotic nuclei and vacuolization in all the brain areas studied. In hippocampus, prefrontal cortex, amygdala and hypothalamus, astrogliosis and reduction of neural viability were observed in sweeteners consumers in comparison with the control group. Chronic consumption of ASP and ACK from early stages of development and during long periods, may promote neural modifications, astrogliosis and decrease neuronal viability in prefrontal cortex, amygdala, hippocampus, and hypothalamus.