The study, published in Phytotherapy Research, evaluated the associations between the habitual ingestion of guarana and anthropometric and biochemical biomarkers of lipid, glucose and oxidative metabolism, in addition to metabolic disorders.
The researchers, from the Universidade Federal de Santa Maria, Brazil, found the prevalence of various metabolic disorders were inversely associated with guarana ingestion in an elderly population residing in the Amazon Riverine region of the Maués municipality (Brazil) – an area traditionally important for guarana production.
The authors said the results “constitute the first epidemiological study to suggest a potentially protective effect of habitual guarana ingestion against metabolic disorders.”
“In general, the results suggest that guarana consumption, most likely due to the bioactive compounds present in the beverage, potentially conveys a protective effect against the metabolic disorders investigated here,” said the authors, led by Cristina da Costa Krewer, from the Universidade Federal de Santa Maria.
“The catechins, caffeine, and other xanthines present in guarana likely contribute to these results; however, the exact mechanism of action remains to be elucidated,” they added.
The guarana plant (Paullinia cupana), known for its high caffeine content, contains a variety of bioactive compounds, including tannins, saponins, catechins, epicatechins, proanthocyanidols.
Experimental models, in addition to in vitro assays have described several biological effects that guarana shares with green tea, including high antioxidant activity, antimicrobial effects and anticarcinogenic properties.
Previous investigations have suggested that guarana positively affects lipid metabolism, enhances weight loss, and increases basal energy expenditure.
“The investigation of guarana consumption is important, in a manner similar to the investigation of other potentially beneficial foods such as green tea, soybeans and red wine, in larger population groups,” said the authors.
The objective of the new study was to analyse the association between guarana consumption and the prevalence of obesity, hypertension, type-2 diabetes and dyslipidemia in an elderly population living in the Maués municipality in Brazil.
The authors explained that the research was performed in Maués “because this location is historically important for guarana production.”
“Evidence has suggested that the native Sateré-Maués people, who live in a native indigenous reserve localized in Maués, were the first to farm guaraná,” they added.
A total of 637 elderly volunteers (aged 60 years or older) were included in the case-controlled study. The elderly participants were classified into those who habitually ingested guarana and a control group of those who had never ingested guarana – based on self-reported data of previous intake.
da Costa Krewer and colleagues reported that the prevalence of metabolic disorders was negatively associated with guarana intake.
“The group that consumed guarana showed a lower prevalence of hypertension, obesity and metabolic syndrome than the group [who never ingested guarana],” they said.
However, the prevalence of type-2 diabetes was found to be identical between the habitual intake and never ingested populations.
Males who habitually ingested guarana were, on average, found to have lower waist circumferences, whilst females in the GI group had lower cholesterol (total and LDL-cholesterol) levels than the control group.
The researchers concluded that the results “indicate that there is a protective effect associated with habitual guarana ingestion,”
They added that the finding that guarana ingestion may reduce the prevalence of metabolic disorders is “in concordance with previous results obtained from experimental models and clinical investigations that used guarana as a supplement.”
However, da Costa Krewer and co-workers warned that due to the cross-sectional design of the study, “it is not possible to determine whether the associations found represent cause-and-effect relationships.”
“We believe that, despite the methodological limitations, the results described in this study suggest that habitual guarana ingestion contributes positively to the prevention of various metabolic disorders in the elderly,” they added.
Source: Phytotherapy Research
Published online ahead of print, doi: 10.1002/ptr.3437
“Habitual Intake of Guaraná and Metabolic Morbidities: An Epidemiological Study of an Elderly Amazonian Population”
Authors: C. da Costa Krewer, E.E. Ribeiro, E.A.M. Ribeiro, R.N. Moresco, et al.