Gymnemic acids lozenge reduces short-term consumption of high-sugar food: A placebo controlled experiment

Suppression of sweet taste-related responses by plant-derived bioactive compounds and eating. Part I: A systematic review in humans

The taste of food plays a crucial role in determining what and how much we eat. Thus, interventions that temporarily block sweet taste receptors offer a promising approach to addressing unhealthy behaviours associated with sugary foods. However, the relationship between reduced sweet taste response and food consumption remains unclear, with contradictory findings. Certain studies suggest that a diminished perception of sweetness leads to a sense of fullness and results in reduced food intake, while others suggest the opposite effect. To shed some light, our systematic review looked into the relationship between diminished sweet taste response and food consumption by examining the effects of bioactive compounds that experimentally inhibit sweetness in healthy individuals. This review was registered in the International Prospective Register of Systematic Reviews and conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Scottish Intercollegiate Guidelines Network, and covered original papers included in Web of Science, PubMed, Scopus, Food Science Source and Food Science and technology abstracts. We identified 33 peer-reviewed English-language studies that fit the topic and met the inclusion criteria. The current literature predominantly focuses on the immediate impact of oral gymnemic acids, failing to provide preliminary evidence in support of the specific threshold hypothesis, above which food consumption decreases and below which the opposite effect occurs. Additionally, there was inconsistency in the findings regarding the short-term desire to eat following sweetness inhibition. Considering the downstream effects on energy intake and their clinical applications, further research is needed to clarify both the acute within-session effects (i.e., not wanting any more now) and the longer-term effects (i.e., deciding not to start eating) linked to oral sweet-taste-suppressing compounds.

The Effect of a 14-Day gymnema sylvestre Intervention to Reduce Sugar Cravings in Adults

Gymnemic-acids (GA) block lingual sweet taste receptors, thereby reducing pleasantness and intake of sweet food. Objective: To examine whether a 14-day gymnema-based intervention can reduce sweet foods and discretionary sugar intake in free-living adults. Healthy adults (n = 58) were randomly allocated to either the intervention group (INT) or control group (CON). The intervention comprised of consuming 4 mg of Gymnema sylvestre containing 75% gymnema acids, a fibre and vitamin supplement, and an associated healthy-eating guide for 14 days; participants in the CON group followed the same protocol, replacing the GA with a placebo mint. Amount of chocolate bars eaten and sensory testing were conducted before and after the 14-day intervention (post-GA or placebo dosing on days zero and 15, respectively). Food frequency questionnaires were conducted on days zero, 15 and after a 28-day maintenance period to examine any changes in intake of sweet foods. A range of statistical procedures were used to analyse the data including Chi square, t-test and two-way analysis of variance. Post dosing, INT consumed fewer chocolates (2.65 ± 0.21 bars) at day zero than CON (3.15 ± 0.24 bars; p = 0.02); there were no differences between groups at day 15 (INT = 2.77 ± 0.22 bars; CON = 2.78 ± 0.22 bars; p = 0.81). At both visits, a small substantive effect (r < 0.3) was observed in the change in pleasantness and desire ratings, with INT showing a slight increase while CON showed a small decrease over the 14-day period. No differences were found in the intake of 9 food categories between groups at any timepoint. There were no differences in consumption of low sugar healthy foods between visits, or by group. The 14-day behavioural intervention reduced pleasantness and intake of chocolate in a laboratory setting. There was no habituation to the mint over the 14-day period. This study is the first to investigate the effect of longer-term gymnema acid consumption on sweet food consumption outside of a laboratory setting; further research is needed to assess how long the effect of the 14-day intervention persists.

An Exploration of the Role of Sugar-Sweetened Beverage in Promoting Obesity and Health Disparities

PURPOSE OF REVIEW

The mechanistic role of sugar-sweetened beverage (SSB) in the etiology of obesity is undetermined. We address whether, compared to other foods, does consumption of SSB (1) automatically lead to failure to compensate for the energy it contains? (2) fail to elicit homeostatic hormone responses? (3) promote hedonic eating through activation of the brain's reward pathways? We followed the evidence to address: (4) Would restriction of targeted marketing of SSB and other unhealthy foods to vulnerable populations decrease their prevalence of obesity?

RECENT FINDINGS

The data are lacking to demonstrate that SSB consumption promotes body weight gain compared with isocaloric consumption of other beverages or foods and that this is linked to its failure to elicit adequate homeostatic hormone responses. However, more recent data have linked body weight gain to reward activation in the brain to palatable food cues and suggest that sweet tastes and SSB consumption heightens the reward response to food cues. Studies investigating the specificity of these responses have not been conducted. Nevertheless, the current data provide a biological basis to the body of evidence demonstrating that the targeted marketing (real life palatable food cues) of SSB and other unhealthy foods to vulnerable populations, including children and people of color and low socioeconomic status, is increasing their risk for obesity. While the mechanisms for the association between SSB consumption and body weight gain cannot be identified, current scientific evidence strongly suggests that proactive environmental measures to reduce exposure to palatable food cues in the form of targeting marketing will decrease the risk of obesity in vulnerable populations.

Suppression of Oral Sweet Sensations during Consumption of Sweet Food in Humans: Effects on Gastric Emptying Rate, Glycemic Response, Appetite, Food Satisfaction and Desire for Basic Tastes

Suppression of oral sweet sensation (OSS) acutely reduces intake of sweet-tasting food due to lower liking. However, little is known about other physiological responses during both the prandial and postprandial phase. Here, we explored the effects of Gymnema sylvestre (GS)-based suppression of OSS of several types of sweet-tasting food (muffin, sweet yogurt, banana) on gastric emptying, blood glucose (BG), plasma insulin (PI), appetite indices (hunger, fullness and prospective consumption), satisfaction and desire for tastes. Fifteen healthy subjects (22 ± 3 years, 9 women) took part in the study. Subjects rinsed their mouth with either GS solution or distilled water before eating the sweet-tasting food. Subjects felt decreased sweet taste intensity and reduced taste liking associated with GS rinsing after consuming each food, compared with rinsing with distilled water (p < 0.05). Gastric emptying, BG, PI and appetite indices during and after the prandial phase did not significantly change with GS rinsing compared to rinsing with distilled water (p > 0.05). Higher desire for sweet taste as well as lower satisfaction (p < 0.05) in the postprandial phase were observed with GS rinsing. These results suggest that the suppression of OSS does not affect gastric emptying, glycemic response and appetite during and after consumption of sweet-tasting food.

Consuming Gymnema sylvestre Reduces the Desire for High-Sugar Sweet Foods

Background. Gymnemic acids, from the plant Gymnema sylvestre (GS), selectively suppress taste responses to sweet compounds without affecting the perception of other taste elements. The aim of this study was to investigate the effect of consuming a GS-containing mint on the desire to consume high-sugar sweet foods directly thereafter. Methods. This study utilized a single-blind, crossover design comparing the consumption of a mint (dissolving tablet) containing 4 mg of gymnemic acids with an isocaloric placebo in 56 healthy young men and women. Participants were given samples of their favourite chocolate (varied between 14–18 g; energy varied between 292–370 kJ) and were directed to rate on their hunger on 100-mm visual analogue scales 30 s prior to consuming high-sugar sweet food (chocolate). They then consumed the GS mint or placebo mint and rated their perceived pleasantness and desire for more chocolate on separate visual analogue scales immediately following consumption of the high-sugar sweet food before being offered up to five additional servings (and asked to rate hunger, pleasantness and desire to eat more chocolate between each ingestion period). Results. The number of chocolate bars eaten decreased by 0.48 bars (21.3%) within a 15-min period of consumption of the GS mint (p = 0.006). Desire to eat more of the high-sugar sweet food (p = 0.011) and pleasantness of the high-sugar sweet food (p < 0.001) was reduced after GS mint intake. Those who reported having a ‘sweet tooth’ had a greater reduction in the pleasantness of chocolate (p = 0.037) and desire to eat more (p = 0.004) after consuming the GS mint for the first serving of a high-sugar sweet food following the mint. Conclusion. Consuming gymnema-containing mints compared to placebo significantly reduced the quantity of chocolate eaten mainly due to a decrease in the desire and pleasantness of consuming it.

Pathways and mechanisms linking dietary components to cardiometabolic disease: thinking beyond calories

Calories from any food have the potential to increase risk for obesity and cardiometabolic disease because all calories can directly contribute to positive energy balance and fat gain. However, various dietary components or patterns may promote obesity and cardiometabolic disease by additional mechanisms that are not mediated solely by caloric content. Researchers explored this topic at the 2017 CrossFit Foundation Academic Conference 'Diet and Cardiometabolic Health - Beyond Calories', and this paper summarizes the presentations and follow-up discussions. Regarding the health effects of dietary fat, sugar and non-nutritive sweeteners, it is concluded that food-specific saturated fatty acids and sugar-sweetened beverages promote cardiometabolic diseases by mechanisms that are additional to their contribution of calories to positive energy balance and that aspartame does not promote weight gain. The challenges involved in conducting and interpreting clinical nutritional research, which preclude more extensive conclusions, are detailed. Emerging research is presented exploring the possibility that responses to certain dietary components/patterns are influenced by the metabolic status, developmental period or genotype of the individual; by the responsiveness of brain regions associated with reward to food cues; or by the microbiome. More research regarding these potential 'beyond calories' mechanisms may lead to new strategies for attenuating the obesity crisis.

Effects of gymnemic acids lozenge on reward region response to receipt and anticipated receipt of high-sugar food

A gymnemic acids lozenge that blocks sweet taste receptors reduced the decision to consume candy in humans even before the candy was tasted after the gymnemic acids dose, suggesting that blocking sweet taste receptors reduces valuation of sweet foods. The present study used functional magnetic resonance imaging (fMRI) to test whether the gymnemic acids lozenge reduces reward region response to both intake and anticipated intake of high-sugar food, as well as ad lib candy intake relative to a placebo lozenge. Here we show for the first time that a gymnemic acids lozenge versus placebo lozenge significantly reduced activation in the striatum and orbitofrontal cortex in response to anticipated tastes of high-sugar milkshake, and significantly reduced dorsolateral prefrontal cortex response to tastes of milkshake. We also replicated evidence that a gymnemic acids lozenge versus placebo lozenge significantly reduced ad lib candy intake. Results also provide novel evidence that an initial taste of a high-sugar food increases reward region (i.e., caudate) response to anticipated intake of more of the high-sugar food. Results suggest that blocking sweet taste receptors not only reduces reward region response to intake of high-sugar foods, but also reduces anticipated reward from high-sugar foods, potentially via a feedback loop regarding the availability of sweet taste receptors to convey perceptual input regarding sweet tastes. Collectively, results imply that the gymnemic acids lozenge might prove useful in decreasing high-sugar food intake.