Herbs and plantsGuarana — energy from the jungle or a quiet blow to the heart?
Sources: 8 · Article: 9 488 characters
Guarana may reduce fatigue, but it cannot be considered safe for every heart.
- Henryk Różański says that guarana stimulates the heart, and that high doses of caffeine can cause a noticeable heartbeat.
- The European Medicines Agency (EMA) states that medicines made from guarana seeds should not be used by people with cardiovascular diseases, including high blood pressure or heart rhythm disorders.
- No adverse effects of these medicines had been reported at the time of the assessment, but this restriction on their use was recommended.
What the authors write
Henryk Różański
Guarana extracts increase the force of the heart's contractions and stimulate its electrical conduction system.
„They increase the contractile force of the heart muscle. They improve lung ventilation. They stimulate the heart's electrical conduction system. They increase the secretion of gastric juice, stimulate peristalsis in the digestive tract, and increase the amount of urine produced. The caffeine and theobromine contained in Paullinia increase perception (the reception) and analysis of sensations, and speed up and improve thought processes.”Zwiększają siłę skurczową mięśnia sercowego Usprawniają wentylację płuc. Pobudzają układ bodźcowo-przewodzący serca. Wzmagają wydzielanie soku żołądkowego, pobudzają ruchy robaczkowe przewodu pokarmowego, wzmagają ilość wydzielanego moczu. Kofeina i teobromina zawarte w Paulinia zwiększają percepcję (odbiór) i analizowanie wrażeń, przyśpieszają i usprawniają procesy myślowe.
Henryk Różański
At high doses of caffeine, a noticeable heartbeat may be felt, and its effect on heart function depends on the individual.
„After high doses of caffeine are given, a noticeable heartbeat is felt, but blood pressure does not rise or rises only slightly. Blood pressure rises when caffeine is given in cases of collapse, fainting, drug poisoning, or carbon monoxide poisoning. It widens the coronary arteries. It increases the contractility and excitability of the heart muscle. Caffeine increases the force of the heart muscle's contractions. It stimulates the heart's electrical conduction system. It should also be remembered that caffeine is not a reliable stimulant of heart function. It also stimulates the vagus nerve, which slows heart activity, so the final effect on the heart depends on physiological condition and the sensitivity of the vagus nerve. Small doses of caffeine often slow the heart, while high doses speed it up.”Po podaniu wysokich dawek kofeiny odczuwane jest wyraźne bicie serca, ale ciśnienie krwi nie wzrasta lub wzrasta nieznacznie. Ciśnienie krwi ulega wzrostowi, jeżeli kofeinę podano w przypadku zapaści, omdlenia, zatrucia narkotykowego, zaczadzenia. Rozszerza naczynia wieńcowe. Zwiększa kurczliwość i pobudliwość mięśnia sercowego. Pod wpływem kofeiny wzrasta siła skurczu mięśnia sercowego. Pobudza układ bodźcowo-przewodzący serca. Należ też pamiętać, że kofeina nie jest pewna w pobudzaniu czynności serca. Pobudza bowiem nerw błędny, który hamuje czynności serca, zatem ostateczny efekt nasercowy zależy od kondycji fizjologicznej i wrażliwości nerwu błędnego. Często małe dawki kofeiny zwalniają czynność serca, a wysokie dawki – przyspieszają.
Henryk Różański
Guarana contains caffeine at a reported level of 3.6–5.8 percent, and more rarely up to 7 percent.
„Guarana contains caffeine 3.6–5.8% (more rarely up to 7%), theobromine 0.03–0.17%, theophylline 0.02–0.06%, proanthocyanidins 10%, and saponins. Commercially available powdered guarana contains about 13% protein, 50–60% sugars, about 3% fat, and provides 1426 kJ/338 kcal (per 100 g); potassium 516 mg, phosphorus 177 mg, and iron 2 mg/100 g.”Guarana zawiera: kofeinę 3,6-5,8% (rzadziej do 7%), teobrominę 0,03-0,17%, teofilinę 0,02-0,06%, proantocyjanidyny 10% i saponiny. Dostępna w handlu sproszkowana guarana: białko ok. 13%, cukry 50-60%, tłuszcze ok. 3%, energia 1426 kJ/338 kcal (100 g); potas 516 mg, fosfor 177 mg, żelazo 2 mg/100 g.
Europejska Agencja Leków (EMA)
Medicines made from guarana seeds were recommended against for people with cardiovascular diseases, such as high blood pressure and heart rhythm disorders.
„The HMPC recommended that these medicines not be used by patients with stomach or duodenal ulcers, an overactive thyroid, or cardiovascular diseases such as high blood pressure and heart rhythm disorders. More information about the risks associated with medicines made from guarana seeds, including precautions for their safe use, can be found in the monograph under the “All documents” tab on the Agency’s website: ema.europa.eu/Find medicine/Herbal medicines for human use.”HMPC zalecił, aby leków tych nie stosować u pacjentów z wrzodami żołądka i jelitadwunastnicy, nadczynnością tarczycy lub chorobami układu krążenia, jak nadciśnienie i zaburzenia rytmu serca. Więcej informacji na temat zagrożeń związanych z lekami otrzymywanymi z nasienia guarany, w tym środki ostrożności dotyczące ich bezpiecznego stosowania, znajduje się w monografii, w zakładce „All documents” („Wszystkie dokumenty”) na stronie internetowej Agencji: ema.europa.eu/Find medicine/Herbal medicines for human use.
Europejska Agencja Leków (EMA)
Guarana seeds may be used for the temporary relief of fatigue and weakness.
„Based on the tradition of long-standing use of guarana seeds, the HMPC concluded that they may be used for the temporary relief of symptoms of fatigue and weakness.”Opierając się na tradycji wynikającej z wieloletniego stosowania nasienia guarany HPMPC doszedł do wniosku, że – na podstawie wieloletnich doświadczeń ze stosowaniem nasienia guarany – może ono być stosowane w celu chwilowegookresowego złagodzenia objawów zmęczenia i słabościosłabienia.
Europejska Agencja Leków (EMA)
No adverse effects of these medicines had been reported at the time of the HMPC assessment.
„No adverse effects associated with the use of these medicines had been reported at the time of the HMPC assessment. The HMPC recommended that these medicines not be used by patients with stomach or duodenal ulcers, an overactive thyroid, or cardiovascular diseases such as high blood pressure and heart rhythm disorders.”W chwili przeprowadzania oceny przez HPMC nie zgłoszono żadnych działań niepożądanych związanych ze stosowaniem tych leków. HMPC zalecił, aby leków tych nie stosować u pacjentów z wrzodami żołądka i jelitadwunastnicy, nadczynnością tarczycy lub chorobami układu krążenia, jak nadciśnienie i zaburzenia rytmu serca.
Research from PubMed · Europe PMC
We selected 2 studies with the best, positive results. This is a selection, not a full review of all research.
Total number of studies on this topic in PubMed: 10.
No harmful changes to the heart were found in rats given a mixture containing guarana, but this result cannot be used to assess guarana alone in humans.
Aim of the study: A novel dietary supplement composed of three well-known phytochemicals, namely, Salvia officinalis (sage) extract, Camellia sinensis (oolong tea) extract, and Paullinia cupana (guarana) extract, and two prominent vitamins (thiamine and niacin) was designed to provide nutritional support by enhancing metabolism and maintaining healthy weight and energy.
Results: Organ-specific serum markers (ALT/AST for the liver; CPK/AST for the heart; BUN/creatinine for the kidneys) and genomic integrity showed no STG-induced changes. Some serum components (lipids and proteins) showed insignificant changes. Overall, rats exposed to STG were more active, and the results suggest that STG exposure produces normal serum chemistry and increased antioxidant capacity in rats fed up to seven times the normal human dose, and does not adversely affect any vital target organs. Additionally, this study reiterates the potential benefits of exposure to a pharmacologically relevant combination of phytochemicals compared with a single phytochemical.
Money for the studycompany together with others · AdvoCare International, Carrollton, Division of Pharmaceutical Sciences of AMS College of Pharmacy
Do the authors have ties to companies?yes — the authors reported it
Did a manufacturer help with the study?YES
Type of studyanimal study
“Not stated” does not mean nobody paid — the database does not always record it.
Guarana improved some cognitive results, but also increased heart rate during exercise and slowed its early return to normal.
Aim of the study: This study investigated the acute effects of guarana supplementation on cognitive, technical, physiological, and psychological responses in soccer players before, during, and after high-intensity 4 vs. 4 small-sided games (SSGs).
Results: Guarana significantly increased mean exercise HR (p < 0.05) and slowed early recovery kinetics (p < 0.05) without altering perceived physical exertion (p > 0.05). At the same time, it significantly reduced perceived mental exertion (p < 0.01) and Total Mood Disturbance (p < 0.001). No significant differences between conditions were noted for 24 h wellness indices (p > 0.05). These findings suggest that acute administration of a low dose of guarana may improve basic attentional readiness and was associated with improved technical performance before exercise, although this performance advantage was reduced after high-intensity physical exertion.
Money for the studyuniversity or foundation · Bielefeld University, Germany
Do the authors have ties to companies?no — the authors say so
Did a manufacturer help with the study?NO
Type of studystudy with random allocation to groups (RCT)
“Not stated” does not mean nobody paid — the database does not always record it.
Perspectives and opinion materials
The content below presents the authors’ opinions, interpretations and hypotheses. It is not treated as equal to scientific studies and systematic reviews.
Orthomolecular Medicine News Service Opinion material
„“Playing God in the Garden,” New York Times Magazine, Oct. 25, 1998.) For its part, the FDA also seems to have abdicated its role as guarantor of food safety.”"Playing God in the Garden" New York Times Magazine, Oct 25, 1998.) For its part, the FDA seems to have abdicated its position as guarantor of food safety, too.
Orthomolecular Medicine News Service Opinion material
„None. Supplement Safety Confirmed by America's Largest Database, by Andrew W. Saul, Editor (OMNS December 16, 2019). The 36th annual report from the American Association of Poison Control Centers shows zero deaths from any vitamin. Supporting data are in Table 22B, pp. 1412–1413, at the very end of the report published in Clinical Toxicology. [1] It is interesting that this is placed so quietly way back there, where hardly any news reporter is likely to see it. But wait, there's more: the AAPCC report shows no deaths from any dietary mineral supplement. There were no fatalities from amino acids, creatine, blue-green algae, glucosamine, or chondroitin.”None.Supplement Safety Confirmed by America's Largest Database by Andrew W. Saul, Editor (OMNS December 16, 2019) The 36th annual report from the American Association of Poison Control Centers shows zero deaths from any vitamin. Supporting data is in Table 22B, p 1412-1413, at the very end of the report published in Clinical Toxicology. [1] It is interesting that it is so quietly placed way back there where nary a news reporter is likely to see it. But wait, there's more: The AAPCC report shows no deaths from any dietary mineral supplement. There were no fatalities from amino acids, creatine, blue-green algae, glucosamine, or chondroitin.
Orthomolecular Medicine News Service Opinion material
„John’s wort, valerian, yohimbe, ma huang/ephedra, guarana, kola nut, or yerba mate.”John's wort, valerian, yohimbe, ma huang/ephedra, guarana, kola nut, or yerba mate.
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