Three-Month Daily Consumption of Sugar-Sweetened Beverages Affects the Liver, Adipose Tissue, and Glucose Metabolism

Effects of metformin on behavioral alterations produced by chronic sucrose consumption in male rats

Excessive consumption of sugary drinks negatively impacts the developing brain, producing long-lasting behavioral and metabolic disorders. Here, we study whether treatment with the antihyperglycemic agent metformin prevents some of the anxiety and memory alterations produced by chronic sucrose consumption. Male Sprague-Dawley rats had unrestricted access to water (control group) and a bottle containing a 10% sucrose solution (sucrose group, SUC) for 35 days. In parallel, a group of animals from SUC received metformin (25 mg/kg or 50 mg/kg, orally; MET 25 and MET 50 groups, respectively). After 2 weeks of metformin treatment, the animals weighed less than controls. SUC and MET 50 groups compensated for the caloric intake from the sugary solution by consuming less chow. In contrast, total energy intake in MET 25 was higher than the rest of the groups, but they still weighed less than control and SUC groups, suggesting that at this concentration, metformin delays body growth. The animals were then tested for the open field (OF), elevated plus maze (EPM) and novel object location (NOL) tests. In the OF, SUC animals spent more time in the central zone of the arena, evidenced by an increased number of entries and the distance traveled there. In the EPM, SUC animals spent more time in the open arms and less time in the central square. Metformin treatment prevented the decreased anxiety observed in SUC animals in the OF and EPM. In the NOL test, SUC animals showed less interest in novelty and metformin treatment did not improve this alteration. The preference for open spaces in the OF and EPM were associated with increased serum triglycerides (TG) and malondialdehyde levels in the medial prefrontal cortex (mPFC) and the hippocampus (HIP), while poor memory performance was associated with high basal blood glucose levels. In conclusion, the decreased anxiety-like behavior produced by chronic sucrose consumption was prevented by metformin treatment, through a mechanism that probably involves normalization of TG levels and decreased oxidative stress in mPFC and HIP.

Effect of lifelong sucrose consumption at human-relevant levels on food intake and body composition of C57BL/6N mice

Introduction

Controversies surround the issue if chronic consumption of a high-sugar diet is detrimental to health or not. This study investigates whether lifelong consumption of a higher sucrose diet will induce overeating, and obesity, and cause metabolic dysfunctions such as hyperglycemia and dyslipidaemia in C57BL/6N mice, compared to a lower sucrose diet.

Methods

Male C57BL/6N mice at 3 weeks of age were randomized into consuming a diet with 25 or 10% kcal from sucrose for the rest of their lives. Body weight, food and water intake, fasting blood glucose, insulin, and lipid levels were measured at regular intervals. At the end of the study, organs and tissues were collected and gene expression was measured.

Results

There was no discernible difference in the impact on food intake, body composition, glucose and lipid homeostasis, liver triglyceride content, life expectancy, as well as gene expression related to intermediary metabolism between mice fed a diet with 10 vs. 25% kcal as sucrose over their lifespan. We also showed that switching from a 25% kcal diet to a 10% kcal diet at different life stages, or vice versa, did not appear to affect these outcomes of interest.

Discussion

The results from our study suggest that lifelong consumption of a higher sugar diet generally did not induce overeating and obesity, disrupt carbohydrate metabolism and lipid homeostasis, and reduce life expectancy compared with a lower sugar diet. Our unorthodox findings disagreed with the popular belief that higher sugar consumption is detrimental to health, which should be confirmed in future studies.

Long-Term Memory Function Impairments following Sucrose Exposure in Juvenile versus Adult Rats

We previously described that excessive consumption of sucrose during youth produces fear memory and anxiety-like behavior in adulthood. Here, we evaluated whether high cognitive function is also affected by studying early sucrose consumption in object recognition memory (NOR). Male Sprague Dawley rats were tested for short-term, long-term, and consolidated NOR after 25 days of unlimited sucrose access in juvenile (PD 25–50) or adult age (PD 75–100). All rats spent equal time exploring the two objects during the sample phase T1. When animals were exposed for 2, 24 h or 7 days later to a copy of the objects presented in T1 and a novel object, the sucrose-exposed juvenile group failed to distinguish between the familiar and the novel objects in contrast with the rest of the groups. Sucrose-exposed animals developed hypertriglyceridemia and glucose intolerance, but juvenile animals showed increased fasting glycemia and sustained the glucose intolerance longer. Moreover, sucrose decreased hippocampal proBDNF expression in juveniles while it was increased in adults, and sucrose also increased RAGE expression in adults. The NOR exploration ratio correlated negatively with basal glycemia and positively with proBDNF. Taken together, these data suggest that sucrose-induced alterations in glucose metabolism may contribute to a long-term decline in proBDNF and impaired recognition memory.

Association between obesity and COVID-19

Background: Since December 2019, most countries have struggled with the novel coronavirus, severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). During the coronavirus disease-2019 (COVID-19) pandemic, weight gain became prevalent because the preventive measures against the spread of SARS-CoV-2 infection resulted in decreased physical activity and increased consumption of unhealthy food among the general public.Current Concepts: Several mechanisms have been proposed for the association between obesity and COVID-19. SARS-CoV-2 infection aggravates inflammation and hypoxia in obese people, which can lead to severe COVID-19 disease. COVID-19 affects the immune system, resulting in various complications. Several cytokines, including interleukin-6, are integral to the progression of COVID-19. Thus, COVID-19-associated inflammation and immune dysfunction predispose patients to the complications of obesity, such as cardiovascular diseases and diabetes mellitus.Discussion and Conclusion: Obese patients are commonly prescribed antidiabetic agents, blood pressure lowering medications, and lipid-lowering medications such as statins. The routine intake of these drugs is a protective factor against all-cause mortality. During the COVID-19 pandemic, preventive measures, such as minimizing team sports and closing public exercise facilities, might have contributed to the weight gain in obese individuals. Thus, an active lifestyle with regular home exercise and a healthy diet should be advised for obese patients.

Integrating the effects of sucrose intake on the brain and white adipose tissue: Could autophagy be a possible link?

Excess dietary sucrose is associated with obesity and metabolic diseases. This relationship is driven by the malfunction of several cell types and tissues critical for the regulation of energy balance, including hypothalamic neurons and white adipose tissue (WAT). However, the mechanisms behind these effects of dietary sucrose are still unclear and might be independent of increased adiposity. Accumulating evidence has indicated that dysregulation of autophagy, a fundamental process for maintenance of cellular homeostasis, alters energy metabolism in hypothalamic neurons and WAT, but whether autophagy could mediate the detrimental effects of dietary sucrose on hypothalamic neurons and WAT that contribute to weight gain is a matter of debate. In this review, we examine the hypothesis that dysregulated autophagy in hypothalamic neurons and WAT is an adiposity-independent effect of sucrose that contributes to increased body weight gain. We propose that excess dietary sucrose leads to autophagy unbalance in hypothalamic neurons and WAT, which increases caloric intake and body weight, favoring the emergence of obesity and metabolic diseases.

Association between Body Mass Index with Sugar-Sweetened and Dairy Beverages Consumption in Children from the Mexico-USA Border

The consumption of sugar-sweetened beverages has been associated with the onset of cardiometabolic diseases. The aim of this study was to describe consumption patterns of sugar-sweetened and dairy beverages and to evaluate their correlation with the body mass index in children residing at the Mexico−USA border. A total of 722 (370 girls, 352 boys) elementary school children aged 9 to 12 years from Tijuana, Mexico, participated in the study. Anthropometric measures were recorded, and a beverage intake questionnaire was completed by the children’s parents. Significant age by sex interactions were found on body mass index Z-scores (p < 0.01). Boys showed higher sugar intake (p < 0.05) and total relative energy consumption from sugar (p < 0.05) than girls. The energy consumption from sugar-sweetened and dairy beverages was similar between sexes (p > 0.05). Sugar intake from beverages was higher than the limit recommended by the World Health Organization in boys (66%) and girls (44%). A high frequency of consumption of sugar-sweetened beverages and similar intake of dairy beverages were found in children from the Mexico−USA border. The high consumption of sugar exceeds international recommendations and should be carefully monitored.

Current WHO recommendation to reduce free sugar intake from all sources to below 10% of daily energy intake for supporting overall health is not well supported by available evidence

Sugar is widely consumed over the world. Although the mainstream view is that high added or free sugar consumption leads to obesity and related metabolic diseases, controversies exist. This narrative review aims to highlight important findings and identify major limitations and gaps in the current body of evidence in relation to the effect of high sugar intakes on health. Previous animal studies have shown that high sucrose or fructose consumption causes insulin resistance in the liver and skeletal muscle and consequent hyperglycemia, mainly because of fructose-induced de novo hepatic lipogenesis. However, evidence from human observational studies and clinical trials has been inconsistent, where most if not all studies linking high sugar intake to obesity focused on sugar-sweetened beverages (SSBs), and studies focusing on sugars from solid foods yielded null findings. In our opinion, the substantial limitations in the current body of evidence, such as short study durations, use of supraphysiological doses of sugar or fructose alone in animal studies, and a lack of direct comparisons of the effects of solid compared with liquid sugars on health outcomes, as well as the lack of appropriate controls, seriously curtail the translatability of the findings to real-world situations. It is quite possible that "high" sugar consumption at normal dietary doses (e.g., 25% daily energy intake) per se-that is, the unique effect of sugar, especially in the solid form-may indeed not pose a health risk for individuals apart from the potential to reduce the overall dietary nutrient density, although newer evidence suggests "low" sugar intake (<5% daily energy intake) is just as likely to be associated with nutrient dilution. We argue the current public health recommendations to encourage the reduction of both solid and liquid forms of free sugar intake (e.g., sugar reformulation programs) should be revised due to the overextrapolation of results from SSBs studies.

Effects of chronic bubble tea administration on behavior and cognition in C57BL/6 mice

PURPOSE

There is a lack of rigorous experimental evidence to verify the effects of bubble tea on body weight and mental health, especially whether it is an addictive thing.

MATERIALS AND METHODS

Male adult C57BL/6 mice were randomly assigned to two groups, including the bubble-tea and the control group. The change in their body weight was calculated. Behavior tests include novel object recognition test (NORT), elevated plus maze test (EPMT), forced swim test (FST), tail suspension test (TST), conditioned place preference (CPP).

RESULTS

There was a significant time effect on weight change of the two groups (F = 36.83, P < 0.01). The bubble tea-treated mice spent significantly less time in the open arms, indicating an increase in anxiety (t = 2.39, P = 0.03). In FST, bubble tea treatment produced a significantly increased immobility time (186.58 ± 29.67 s) as compared to pure water treated group (112.50 ± 46.67 s) (t = -3.79, P < 0.01). Similarly, the immobility time in the TST was also significantly increased by bubble tea treatment (437.63 ± 27.72 s) compared to the treatment with pure water (340.24 ± 77.22 s) (t = -3.36, P < 0.01). We investigated the rewarding effects of bubble tea, using the CPP paradigm, which measures the rewarding properties of abused drugs. Independent-samples t-test revealed no significant difference between the two groups (t = -0.47, P = 0.65).

CONCLUSION

In conclusion, we showed that long-term administration of bubble tea could not induce addictive behavior in mice. Meanwhile, the long-term effects of bubble tea on weight were also very limited. However, long-term consumption of bubble tea can lead to anxiety and depression-like behaviors and impair cognitive function in mice.

Are fat and sugar just as detrimental in old age?

Aging and poor nutrition are independent risk factors for the development of chronic disease. When young animals are given diets high in fat or sugar, they exhibit hallmarks of aging like mitochondrial dysfunction and inflammation, and also develop a greater risk for age-related disease. The same mitochondrial dysfunction and inflammation that progress with aging may also further predispose older individuals to dietary insults by fat and sugar. The purpose of this work is to review the most recent studies that address the impact of fat and sugar consumption on hallmarks of aging (mitochondrial dysfunction and inflammation). Findings from these studies show that obesogenic, high-fat diets can exacerbate age-related disease and hallmarks of aging in young animals, but high-fat diets that are non-obesogenic may play a beneficial role in old age. In contrast, high-sugar diets do not require an obesogenic effect to induce mitochondrial dysfunction or inflammation in young rodents. Currently, there is a lack of experimental studies addressing the impact of sugar in the context of aging, even though empirical evidence points to the detrimental effect of sugar in aging by contributing to a variety of age-related diseases. Fig. 1 Mitochondrial dysfunction and altered cellular communication (e.g. inflammation) progress with advancing age and increase the risk for age-related disease (ARD). Given the physiological changes that occur with age, the impact of high-fat (HFD) and high-sugar diets (HSD) may differ in later and earlier stages of life. HFD can promote the development of hallmarks of aging in young animals and can also exacerbate the risk for ARD when consumed at an old age. However, non-obesogenic high-fat diets may also reduce the risk for ARD in old age by acting on these hallmarks of aging. On the other hand, HSD promotes mitochondrial dysfunction and inflammation without necessarily inducing weight gain in young animals. Empirical evidence points to sugar as a major contributor to age-related disease and more experimental studies are needed to clarify whether aged individuals are more susceptible to its effects.

Beverages and Non-alcoholic fatty liver disease (NAFLD): Think before you drink

BACKGROUND & AIMS

Beverages and Non-alcoholic fatty liver disease (NAFLD) both the terms are associated with westernized diet and sedentary lifestyle. Throughout recent decades, dietary changes have boosted demand of beverages to meet the liquid consumption needs, among which rising consumption of several calorie-rich beverages have increased the risk of fatty liver disease. Meanwhile, certain beverages have capacity to deliver many unanticipated health benefits thereby reducing the burden of NAFLD and metabolic diseases. The present review therefore addresses the increasing interconnections between beverages intake among population, dietary patterns and the overall effect of these beverage on the development and prevention of NAFLD. Methods In the present review, some frequently consumed beverage groups have been analyzed in light of their role in the advancement and prevention of NAFLD, including sugar sweetened, hot and alcoholic beverages. The nutritional composition of different beverages makes the progression of NAFLD distinctive.

RESULTS

The ingestion of sugar-rich beverages has demonstrated the metabolic burden and in all cases, raises the risk of NAFLD, while intake of coffee and tea has decreased this risk without any significant adverse effects. In some cases, low to moderate alcohol intake has been shown to minimize the risk of advanced fibrosis and NAFLD-mortality.

CONCLUSION

Together, this review discusses and supports work on new dietary approaches and clinical studies to accomplish nutrition-oriented NAFLD care by improving the drinking habits.

Inflammatory Bowel Diseases: Is There a Role for Nutritional Suggestions?

Nutrition has an important impact on inflammatory bowel diseases (IBD). In particular, several studies have addressed its role in their pathogenesis, showing how the incidence of IBD significantly increased in recent years. Meanwhile, nutrition should be considered a component of the treatment of the disease, both as a therapy itself, and especially in the perspective of correcting the various nutritional deficiencies shown by these patients. In this perspective, nutritional suggestions are very important even in the most severe forms of IBD, requiring hospitalization or surgical treatment. Although current knowledge about nutrition in IBD is increasing over time, nutritional suggestions are often underestimated by clinicians. This narrative review is an update summary of current knowledge on nutritional suggestions in IBD, in order to address the impact of nutrition on pathogenesis, micro- and macro-nutrients deficiencies (especially in the case of sarcopenia and obesity), as well as in hospitalized patients.

Efficacy and Safety of Lactobacillus plantarum K50 on Lipids in Koreans With Obesity: A Randomized, Double-Blind Controlled Clinical Trial

BACKGROUND

Only few studies have investigated the role of probiotics in the development of obesity. We aimed to determine the efficacy and safety of an intake of Lactobacillus plantarum K50 (LPK) on body fat and lipid profiles in people with obesity.

METHODS

This randomized, double-blind, placebo-controlled, clinical trial involved 81 adults with a body mass index of 25-30 kg/m² who were assigned randomly to a diet including 4 × 10⁹ colony-forming unit of LPK or a placebo. Changes in body fat, anthropometric parameters, and biomarkers of obesity were compared using a linear mixed-effect model.

RESULTS

After 12 weeks of treatment, body weight, fat mass, and abdominal fat area did not change significantly in the two groups. However, total cholesterol levels decreased from 209.4 ± 34.4 mg/dL to 203.5 ± 30.9 mg/dL in the LPK group, but increased from 194.7 ± 37.5 mg/dL to 199.9 ± 30.7 mg/dL in the placebo group (P = 0.037). Similarly, triglyceride levels decreased from 135.4 ± 115.8 mg/dL to 114.5 ± 65.9 mg/dL in the LPK group, with a significant difference between groups. LPK supplementation also tended to decrease leptin levels compared with placebo. It also changed the distribution of gut microbiota significantly, with an increase in L. plantarum and a decrease in Actinobacteria, both of whose changes in abundance were correlated with changes in visceral adiposity, with borderline significance.

CONCLUSION

A 12-week consumption of LPK reduced the total cholesterol and triglyceride levels significantly with favorable alterations in microbiota, suggesting potential benefits for controlling blood lipid profiles.

Effects of High White and Brown Sugar Consumption on Serum Level of Brain-Derived Neurotrophic Factor, Insulin Resistance, and Body Weight in Albino Rats

Background

In recent decades, consumption of simple sugars has increased dramatically, which contributes to health problems including insulin resistance and obesity. In this study, we investigated the effects of high concentrations of white sugar (WS) and brown sugar (BS) on serum concentration of brain-derived neurotrophic factor (BDNF), insulin resistance, and body weight in albino rats.

Methods

Twenty-four male Wistar rats were randomly divided into three groups: control, a group treated with 15% WS, and a group treated with 15% BS. Rats were given WS and BS by gavage (daily) for 42 days. At the end of the intervention period, serum level of BDNF, insulin resistance, and body weight were measured.

Results

Body weight and insulin resistance were significantly increased and serum BDNF level was decreased in both WS and BS groups compared to the control group (P<0.05). In the WS-treated rats, the amount of changes in the insulin resistance, body weight, and serum BDNF level was greater compared to that in BS-treated (P<0.05).

Conclusion

Due to the adverse effects of consuming high levels of WS and BS on serum level of BDNF, insulin resistance, and body weight, high intakes of these sweeteners are not recommended.

Effect of Fibroblast Growth Factor 21 on the Development of Atheromatous Plaque and Lipid Metabolic Profiles in an Atherosclerosis-Prone Mouse Model

Fibroblast growth factor 21 (FGF21) is a hormonal regulator of lipid and glucose metabolism. We aimed to investigate the effect of an FGF21 analogue (LY2405319) on the development of atherosclerosis and its associated parameters. ApoE^−/− mice were fed an atherogenic diet for 14 weeks and were randomly assigned to control (saline) or FGF21 (0.1 mg/kg) treatment group (n = 10/group) for 5 weeks. Plaque size in the aortic arch/valve areas and cardiovascular risk markers were evaluated in blood and tissues. The effects of FGF21 on various atherogenesis-related pathways were also assessed. Atherosclerotic plaque areas in the aortic arch/valve were significantly smaller in the FGF21 group than in controls after treatment. FGF21 significantly decreased body weight and glucose concentrations, and increased circulating adiponectin levels. FGF21 treatment alleviated insulin resistance and decreased circulating concentrations of triglycerides, which were significantly correlated with plaque size. FGF21 treatment reduced lipid droplets in the liver and decreased fat cell size and inflammatory cell infiltration in the abdominal visceral fat compared with the control group. The monocyte chemoattractant protein-1 levels were decreased and β-hydroxybutyrate levels were increased by FGF21 treatment. Uncoupling protein 1 expression in subcutaneous fat was greater and fat cell size in brown fat was smaller in the FGF21 group compared with controls. Administration of FGF21 showed anti-atherosclerotic effects in atherosclerosis-prone mice and exerted beneficial effects on critical atherosclerosis pathways. Improvements in inflammation and insulin resistance seem to be mechanisms involved in the mitigation of atherosclerosis by FGF21 therapy.

Effect of Lactobacillus sakei, a Probiotic Derived from Kimchi, on Body Fat in Koreans with Obesity: A Randomized Controlled Study

BACKGROUND

The increased prevalence of obesity has led to increases in the prevalence of chronic diseases worldwide. There is interest whether probiotics have an effect on obesity, but the effectiveness and safety of only a few probiotics for the treatment of obesity have been reported. The purpose of this study was to investigate whether ingestion of Lactobacillus sakei (CJLS03) derived from kimchi causes weight loss in people with obesity.

METHODS

This randomized, double-blind, placebo-controlled, clinical trial involved 114 adults with a body mass index (BMI) ≥25 kg/m2 who were assigned randomly to a CJLS03 or placebo group. The groups received two allocations of either 5×109 colony-forming units of CJLS03/allocation or the equivalent vehicle for 12 weeks. Demographic and biochemical parameters, and body composition including fat and muscle mass were measured at baseline and after 12 weeks. Changes in body fat, weight, and waist circumference were compared between the two treatment groups. Adverse events were monitored during study period.

RESULTS

Body fat mass decreased by 0.2 kg in the CJLS03 group and increased by 0.6 kg in the placebo group (0.8 kg difference, P=0.018). After the 12 weeks, waist circumference was 0.8 cm smaller in the CJLS03 group than in the placebo group (P=0.013). BMI and body weight did not change after the 12 weeks. Adverse events were mild and did not differ between the two groups.

CONCLUSION

These data suggest that L. sakei (CJLS03) might help people with obesity reduce body fat mass without serious side effects (ClinicalTrials.gov: NCT03248414).