Long-Term Cola Intake Does Not Cause Evident Pathological Alterations in the Femoral Bone Microstructure: An Animal Study in Adult Mice

Short-term animal experiments and association studies in humans have shown that cola intake may have a detrimental impact on bone mineral density (BMD); however, other bone parameters have not been investigated. This study examined the effects of long-term cola consumption on the femoral bone microstructure using adult mice (n = 32) as an animal model, which were divided into water and cola groups depending on whether they received water or cola along with a standard rodent diet for 6 months. Micro-computed tomography revealed that cola intake did not significantly affect all measured parameters characterizing trabecular bone mass and microarchitecture, as well as cortical microarchitecture and geometry in both sexes, although a slight deterioration of these parameters was noted. Cola consumption also resulted in a slightly, statistically insignificant worsening of bone mechanical properties. In contrast to female mice, males receiving cola had a lower area of primary osteons' vascular canals. Nevertheless, long-term cola intake did not cause evident pathological alterations in the femur of adult mice, possibly due to a balanced diet and no restriction of physical activity. Therefore, the adverse effects of cola consumption on BMD, the only bone parameter studied so far, may be caused by other risk and lifestyle factors.

Acute effect of cola and caffeine on locomotor activity in drosophila and rat

Caffeine is well known for reducing fatigue and its effect on behavior is widely studied. Usually, caffeine is not ingested in its pure form but rather in sugar-sweetened beverages such as cola. Our aim was to compare the acute effect of cola and caffeine on locomotor activity. Rats and flies ingested cola or caffeine solution for 24 hours. The open field test revealed higher locomotor activity in cola groups for both flies and rats. Surprisingly, no differences have been observed between caffeineand control group. We conclude that caffeine itself does not explain the effect of cola on locomotor activity. Effect of cola cannot be generalized and interpreted for any caffeinated drink with other contents. Rather, the observed effect on locomotor activity may be caused by interaction of caffeine with other substances present in cola.

Worsening of Oxidative Stress, DNA Damage, and Atherosclerotic Lesions in Aged LDLr-/- Mice after Consumption of Guarana Soft Drinks

BACKGROUND

Excessive consumption of soft drinks (SD) has become a health problem worldwide due to its association with related cardiovascular diseases. We investigated the possible impacts associated with the consumption of Brazilian guarana (normal and zero) SD in dyslipidemic mice, thus mitigating potential clinical confounders such as poor-quality diet, lifestyle, body composition, and/or comorbidities.

METHODS

Sixteen-month-old LDLr-/- mice were divided into the following groups: (1) control; (2) GSD: normal guarana SD; and (3) Z-GSD: zero guarana SD. All were fed ad libitum, and blood pressure was measured noninvasively. After 8 weeks, aorta, blood, liver, and stomach samples were collected for histological and biochemical analyses.

RESULTS

Guarana soft drinks increased atherosclerosis (~60%) and were associated with hypercholesterolemia, hypertension, oxidative stress, DNA fragmentation, and apoptosis (~2-fold) of blood cells, besides presenting an increase in liver and gastric damage even in normoglycemia. Interestingly, Z-GSD did not cause the aforementioned changes, except in hemodynamic and renal parameters.

CONCLUSIONS

Chronic administration of GSD is prooxidative, compromising the cardiovascular, gastric, and hepatic systems; the effects are due at least in part to free sugar consumption but not to guarana extract per se.

Beneficial effect of sugar-sweetened beverages on the risk of urinary tract infections

Urinary tract infections (UTI) are among the most common bacterial infections. Drinking more liquids increases the frequency of urination and it is recommended as part of the prevention and/or management of UTI. The intake of sugar-sweetened beverages (SSB) is associated with obesity, diabetes and metabolic syndrome. However, cola and other SSB increase liquid intake and diuresis and could, thus, affect the risk of UTI and its complications. We hypothesize that intake of cola has a protective effect on UTI and pyelonephritis. Using an animal model of UTI, we have confirmed that dehydration with minimal urine output leads to higher bacterial counts in the kidneys in comparison to control mice (p = 0.01). The intake of SSB increased liquid intake and thus also diuresis and decreased renal bacterial counts as a marker of induced pyelonephritis (p = 0.036). The preliminary results show that dehydration is a risk factor for UTI and that higher diuresis induced by drinking SSB might be protective against pyelonephritis. The underlying mechanisms could include increased voiding frequency but potentially also active compounds in cola such as caffeine. These findings might have implications for the management of individuals at high risk of UTI. Further studies should verify the hypothesis and evaluate the practical relevance of this concept.

Cardiorenal Involvement in Metabolic Syndrome Induced by Cola Drinking in Rats: Proinflammatory Cytokines and Impaired Antioxidative Protection

We report experimental evidence confirming renal histopathology, proinflammatory mediators, and oxidative metabolism induced by cola drinking. Male Wistar rats drank ad libitum regular cola (C, n = 12) or tap water (W, n = 12). Measures. Body weight, nutritional data, plasma glucose, cholesterol fractions, TG, urea, creatinine, coenzyme Q₁₀, SBP, and echocardiograms (0 mo and 6 mo). At 6 months euthanasia was performed. Kidneys were processed for histopathology and immunohistochemistry (semiquantitative). Compared with W, C rats showed (I) overweight (+8%, p < 0.05), hyperglycemia (+11%, p < 0.05), hypertriglyceridemia (2-fold, p < 0.001), higher AIP (2-fold, p < 0.01), and lower Q₁₀ level (−55%, p < 0.05); (II) increased LV diastolic diameter (+9%, p < 0.05) and volume (systolic +24%, p < 0.05), posterior wall thinning (−8%, p < 0.05), and larger cardiac output (+24%, p < 0.05); (III) glomerulosclerosis (+21%, p < 0.05), histopathology (+13%, p < 0.05), higher tubular expression of IL-6 (7-fold, p < 0.001), and TNFα (4-fold, p < 0.001). (IV) Correlations were found for LV dimensions with IL-6 (74%, p < 0.001) and TNFα (52%, p < 0.001) and fully abolished after TG and Q₁₀ control. Chronic cola drinking induced cardiac remodeling associated with increase in proinflammatory cytokines and renal damage. Hypertriglyceridemia and oxidative stress were key factors. Hypertriglyceridemic lipotoxicity in the context of defective antioxidant/anti-inflammatory protection due to low Q₁₀ level might play a key role in cardiorenal disorder induced by chronic cola drinking in rats.

Exercise Ameliorates Endocrine Pancreas Damage Induced by Chronic Cola Drinking in Rats

Purpose

This study evaluates whether the daily practice of an exercise routine might protect from endocrine pancreas damage in cola drinking rats.

Methods

Forty-eight Wistar rats were randomly assigned to 4 groups depending on a) beverage consumption ad libitum, water (W) or cola beverage (C), and b) physical activity, sedentary (S) or treadmill running (R). Accordingly, 4 groups were studied: WS (water sedentary), WR (water runner), CS (cola sedentary) and CR (cola runner). Body weight, nutritional data, plasma levels of glucose, creatinine, total cholesterol and cholesterol fractions, and triglycerides (enzymocolorimetry), and systolic blood pressure (plethysmography) were measured. After 6 months, euthanasia was performed (overdose sodium thiopental). Pancreatic tissue was immediately excised and conventionally processed for morphometrical and immunohistochemical determinations.

Results

The effects of running and chronic cola drinking on pancreas morphology showed interaction (p<0.001) rather than simple summation. Cola drinking (CS vs WS) reduced median pancreatic islet area (-30%, 1.8 10⁴ μm² vs 2.58 10⁴ μm², p<0.0001) and median β-cell mass (-43%, 3.81 mg vs 6.73 mg, p<0.0001), and increased median α/β ratio (+49%, 0.64 vs 0.43, p< 0.001). In water drinking rats (WR vs WS), running reduced median α-cell mass (-48%, 1.48 mg vs 2.82 mg, p<0.001) and α/β ratio (-56%, 0.19 vs 0.43, p<0.0001). Differently, in cola drinking rats (CR vs CS), running partially restored median islet area (+15%, 2.06 10⁴ μm² vs 1.79 10⁴ μm², p<0.05), increased median β-cell mass (+47%, 5.59 mg vs 3.81 mg, p <0.0001) and reduced median α/β ratio (-6%, 0.60 vs 0.64, p<0.05).

Conclusion

This study is likely the first reporting experimental evidence of the beneficial effect of exercise on pancreatic morphology in cola-drinking rats. Presently, the increase of nearly 50% in β cells mass by running in cola drinking rats is by far the most relevant finding. Moderate running, advisably indicated in cola consumers and patients at risk of diabetes, finds here experimental support.

Chronic effects of soft drink consumption on the health state of Wistar rats: A biochemical, genetic and histopathological study

The present study was performed to examine the effects of chronic soft drink consumption (SDC) on oxidative stress, biochemical alterations, gene biomarkers and histopathology of bone, liver and kidney. Free drinking water of adult male Wistar rats was substituted with three different soft drinks: Coca‑Cola, Pepsi and 7‑Up, for three consecutive months. The serum and organs were collected for examining the biochemical parameters associated with bone, liver and kidney functions. Semi‑quantitative reverse transcription polymerase chain reaction was used to observe the changes in the expression of genes in the liver and kidney, which are associated with oxidative stress resistance. Histopathological investigations were performed to determine the changes in bone, liver and kidney tissues using hematoxylin and eosin stains. SDC affected liver, kidney and bone function biomarkers. Soft drinks increased oxidative stress, which is represented by an increase in malondialdehyde and a decrease in antioxidant levels. SDC affected serum mineral levels, particularly calcium and phosphorus. Soft drinks downregulated the expression levels of glutathione‑S‑transferase and super oxide dismutase in the liver compared with that of control rats. Rats administered Coca‑Cola exhibited a hepatic decrease in the mRNA expression of α2‑macroglobulin compared with rats administered Pepsi and 7‑Up. On the other hand, SDC increased the mRNA expression of α1‑acid glycoprotein. The present renal studies revealed that Coca‑Cola increased the mRNA expression levels of desmin, angiotensinogen and angiotensinogen receptor compared with the other groups, together with mild congestion in renal histopathology. Deleterious histopathological changes were reported predominantly in the bone and liver of the Coca‑Cola and Pepsi groups. In conclusion, a very strict caution must be considered with SDC due to the increase in oxidative stress biomarkers and disruption in the expression of certain genes associated with the bio‑vital function of both the liver and kidney.

Prenatal dietary load of Maillard reaction products combined with postnatal Coca-Cola drinking affects metabolic status of female Wistar rats

Aim

To assess the impact of prenatal exposure to Maillard reaction products (MRPs) -rich diet and postnatal Coca-Cola consumption on metabolic status of female rats. Diet rich in MRPs and consumption of saccharose/fructose sweetened soft drinks is presumed to impose increased risk of development of cardiometabolic afflictions, such as obesity or insulin resistance.

Methods

At the first day of pregnancy, 9 female Wistar rats were randomized into two groups, pair-fed either with standard rat chow (MRP-) or MRPs-rich diet (MRP+). Offspring from each group of mothers was divided into two groups and given either water (Cola-) or Coca-Cola (Cola+) for drinking ad libitum for 18 days. Oral glucose tolerance test was performed, and circulating markers of inflammation, oxidative stress, glucose and lipid metabolism were assessed.

Results

MRP+ groups had higher weight gain, significantly so in the MRP+/Cola- vs MRP-/Cola-. Both prenatal and postnatal intervention increased carboxymethyllysine levels and semicarbazide-sensitive amine oxidase activity, both significantly higher in MRP+/Cola + than in MRP-/Cola-. Total antioxidant capacity was lower in MRP+ groups, with significant decrease in MRP+/Cola + vs MRP-/Cola+. Rats drinking Coca-Cola had higher insulin, homeostatic model assessment of insulin resistance, heart rate, advanced oxidation of protein products, triacylglycerols, and oxidative stress markers measured as thiobarbituric acid reactive substances compared to rats drinking water, with no visible effect of MRPs-rich diet.

Conclusion

Metabolic status of rats was affected both by prenatal and postnatal dietary intervention. Our results suggest that combined effect of prenatal MRPs load and postnatal Coca-Cola drinking may play a role in development of metabolic disorders in later life.