1.
Effect of Chamomile on the Complications of Cancer: A Systematic Review.
Maleki, M, Mardani, A, Manouchehri, M, Ashghali Farahani, M, Vaismoradi, M, Glarcher, M
Integrative cancer therapies. 2023;22:15347354231164600
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Plain language summary
Cancer and its treatments are associated with a wide range of complications such as mucositis, nausea/vomiting and dermatitis as well as implication for mental health, such as anxiety and depression, which can reduce quality of life (QOL) of patients. Chamomile is a commonly used medicinal herbal that is used in various forms orally and topically. The aim of this systematic review was to evaluate the effectiveness of chamomile, in its various forms of administration, for complications of cancer (any type) and its treatments. 18 controlled intervention studies including 1099 patients were included in the review. Due to the heterogeneity of the studies a meta-analysis was not possible. Benefits were reported for locally applied forms of chamomile for prevention of mucositis (7 of 8 studies), topical application for prevention of dermatitis or phlebitis (4/5), aromatherapy massage for anxiety (2) and QOL (2), tea for depression but not anxiety (1). No effect was seen of syrup for QOL (1). No side effects were reported in the included studies. The authors conclude that chamomile is a safe method to help mitigate the suffering from cancer complications.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Oral use of chamomile infusion may be helpful for people receiving treatment for cancer.
- Studies of this intervention report no safety concerns.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This systematic review examined the use of chamomile in the support of people receiving treatment for cancer. Studies of a variety of chamomile preparations were considered.
Methods
- The authors retrieved 2240 studies from 5 on-line databases, from which 18 studies met the inclusion criteria for analysis.
- Fifteen of these studies were randomised control trials (RCT), three were non-randomised studies. German (Matricaria recutita) and Roman (Chamaemelum nobile) chamomile varieties were included. Studies using blends with other herbs were excluded.
- A narrative review was produced due to heterogeneous patient groups, preparations and trial protocols.
Results
- 1099 patients were included in the analysis, 57% female.
- Risk of bias assessment of 15 RCTs identified 2 RCTs with high risk of bias in blinding or in reporting outcome data.
- Studies in several cancer types were included, four in head and neck cancer (HNC), four in leukaemia, three in breast cancer, one in digestive system cancers, remaining in mixed cancer types.
- Eight studies reported the impact on oral mucositis of chamomile infusions used as mouthwash, or ice chips, or applied as an oral gel. Patients were receiving chemotherapy orstem cell transplantation, with interventions for up to 21 days after chemotherapy. Seven studies reported reduced severity and/or duration of mucositis and associated pain. One study of 14 days’ use after 5-fluorouracil treatment for colorectal cancer showed no impact on oral mucositis.
- One of three studies of psychological impact of cancer treatment used chamomile tea and reported no impact on anxiety but decreased depression. In comparison, two studies of weekly aromatherapy massage using chamomile oil reported reduced anxiety.
- One RCT in children with acute lymphoblastic leukaemia reported increased neutrophil count with 125mg chamomile in syrup versus placebo (p=0.019, 955 CI 15.076-171.324)
- One RCT in breast cancer randomised 45 women receiving usual antiemetics to additional chamomile capsules (500mg) or ginger (500mg) capsules, twice daily for 5 days before and after chemotherapy, or control group of no additional botanicals. Both botanical interventions reduced frequency of vomiting compared with the control group. Frequency of nausea was also reduced by ginger but not by chamomile.
- Five studies evaluated external treatments of chamomile on skin complications of radiotherapy. Reduction in radiation dermatitis in HNC patients with compresses soaked in chamomile infusion was reported.
- No side effects of using chamomile preparations were reported by the studies included in the systematic review.
Conclusion
Chamomile has been studied in a variety of preparations for people receiving treatment for cancer. Several RCTs reported significant amelioration of common side effects of cancer treatments, with reduced severity and/or duration of oral mucositis and associated pain.
Clinical practice applications:
- Chamomile infusion used in the mouth, as mouthwash or ice chips, may be useful for oral mucositis, a common side effect of cancer treatment
- Chamomile infusion may also be considered for mental wellbeing
- Several protocols for using chamomile preparations are described in the review and practitioners may refer to the individual studies cited
- This use of chamomile in the described applications appears to be safe
- (Reviewer’s note: allergy to ragwort would be a contraindication for use of chamomile preparations)
Considerations for future research:
- More detailed comparisons of chamomile preparations would be useful, for use in oral mucositis
- Topical applications may be studied further by researchers in aromatherapy.
Abstract
BACKGROUND AND OBJECTIVES Despite significant advances in the diagnosis and treatment of cancer, many people across the world still suffer from this chronic disease and its complications. Chamomile as an herbal medicine has gained an increasing attention for relieving cancer complications. This study aimed to integrate and synthesize current international evidence regarding the effect of chamomile on cancer complications. METHODS A systematic review was undertaken. Five online databases including Web of Science, PubMed [including MEDLINE], Cochrane Library, Scopus, and Embase were searched and articles published from inception to January 2023 were retrieved. All clinical trials and similar interventional studies on human subjects examining the effects of chamomile on cancer complications were included in the review and research synthesis. Relevant data were extracted from eligible studies after quality appraisals using proper methodological tools. The review results were presented narratively given that meta-analysis was impossible. RESULTS A total of 2240 studies were retrieved during the search process, but 18 articles were selected. The total sample size was 1099 patients with cancer of which 622 participants were female. Fifteen studies used an RCT design. Various forms of chamomile were used such as mouthwash, topical material, tea, capsule, syrup and aromatherapy massage. Chamomile effectively reduced oral mucositis, skin complications, depression, and vomiting and also improved appetite and quality of life among cancer patients. CONCLUSION The use of chamomile as a non-pharmacologic and safe method can be helpful for mitigating cancer complications in patients with cancer. Therefore, it can be incorporated into routine care along with other therapeutic measures to reduce patients' suffering related to cancer. SYSTEMATIC REVIEW REGISTRATION NUMBER (PROSPERO): CRD42022307887.
2.
Effect of dietary nitrate on human muscle power: a systematic review and individual participant data meta-analysis.
Coggan, AR, Baranauskas, MN, Hinrichs, RJ, Liu, Z, Carter, SJ
Journal of the International Society of Sports Nutrition. 2021;18(1):66
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Previous reviews have concluded that dietary nitrate (NO3−) improves maximal neuromuscular power in humans, but these were based on a limited number of studies. This is the first systematic review and meta-analysis evaluating the effects of dietary NO3− supplementation on muscular power in humans. The study also aims to quantify the size of this beneficial effect. 19 studies with a total of 268 participants were included. Most of these used concentrated beetroot juice as the source of NO3− given as an acute dose (short term high level). A positive effect of dietary NO3− on muscle power was observed in all 19 studies. Analyses were done on sub groups - age, sex and the amount of muscle mass engaged in the activity. Dietary NO3− intake significantly increases maximal muscle power in humans. The magnitude of this effect has practical and clinical importance; not just for athletes but also for patient groups. This effect is independent of subject age, sex, or the amount of muscle mass engaged in the activity but may be greater with acute vs. repeated dosing. Further research is needed to determine factors such as the optimal supplementation regimen and target population.
Expert Review
Conflicts of interest:
None
Take Home Message:
- This meta-analysis lends quantitative support to previous narrative reviews that nitrate supplementation can enhance maximal power output.
- These findings are highly relevant to team and strength sport athletes, who may not otherwise be supplementing with nitrates.
- These findings are also highly relevant for older populations, where risk of falls and fractures are high and can lead to significant adverse effects on health and quality of life.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
- In 2007, researchers uncovered the ingestion of dietary nitrates reduced the oxygen cost of submaximal exercise, and since, over 100 studies have examined the effects of nitrates on endurance performance.
- With regards to the impact of nitrates on maximal force output, only trivial results had been previously found.
- This review study found that while nitrates do not impact force development, they do demonstrate primary effect on the speed of muscle contraction (i.e. muscular power is the product of force x speed).
- The reviews primary finding was that nitrate intake can significantly enhance muscular power, regardless of subject age or sex.
Clinical practice applications:
- These new findings highlight the ability of dietary nitrates to improve neuromuscular power production is highly relevant for team sport athletes, due to the explosive nature of these sports with constant accelerations and decelerations during training and competition.
- In the general population, falls and fractures amongst older adults significantly reduces quality of life and costs the healthcare system hundreds of millions of pounds to treat.
- Improved contractile properties of muscle, most notably speed of contraction, may offer protection to older adults as well as the benefit of additional nitric oxide (NO) to support vascular health as well.
- The typical intake of dietary nitrates in the general population is about 31-185mg/day in Europe and 40-100mg/day in North America. Most studies use doses between 300-600mg of dietary nitrates. Increasing dietary or supplemental intake is key to achieving the neuromuscular effect.
Considerations for future research:
- The results of the present meta-analysis clearly demonstrate that dietary nitrates increases muscle power in humans, but the mechanism responsible for this effect is still unclear.
- There are notable differences between rodent and human metabolism of dietary nitrates, therefore the biochemical mechanism by which nitrate intake improves human muscle power requires additional study.
Abstract
BACKGROUND Previous narrative reviews have concluded that dietary nitrate (NO3-) improves maximal neuromuscular power in humans. This conclusion, however, was based on a limited number of studies, and no attempt has been made to quantify the exact magnitude of this beneficial effect. Such information would help ensure adequate statistical power in future studies and could help place the effects of dietary NO3- on various aspects of exercise performance (i.e., endurance vs. strength vs. power) in better context. We therefore undertook a systematic review and individual participant data meta-analysis to quantify the effects of NO3- supplementation on human muscle power. METHODS The literature was searched using a strategy developed by a health sciences librarian. Data sources included Medline Ovid, Embase, SPORTDiscus, Scopus, Clinicaltrials.gov , and Google Scholar. Studies were included if they used a randomized, double-blind, placebo-controlled, crossover experimental design to measure the effects of dietary NO3- on maximal power during exercise in the non-fatigued state and the within-subject correlation could be determined from data in the published manuscript or obtained from the authors. RESULTS Nineteen studies of a total of 268 participants (218 men, 50 women) met the criteria for inclusion. The overall effect size (ES; Hedge's g) calculated using a fixed effects model was 0.42 (95% confidence interval (CI) 0.29, 0.56; p = 6.310 × 10- 11). There was limited heterogeneity between studies (i.e., I2 = 22.79%, H2 = 1.30, p = 0.3460). The ES estimated using a random effects model was therefore similar (i.e., 0.45, 95% CI 0.30, 0.61; p = 1.064 × 10- 9). Sub-group analyses revealed no significant differences due to subject age, sex, or test modality (i.e., small vs. large muscle mass exercise). However, the ES in studies using an acute dose (i.e., 0.54, 95% CI 0.37, 0.71; p = 6.774 × 10- 12) was greater (p = 0.0211) than in studies using a multiple dose regimen (i.e., 0.22, 95% CI 0.01, 0.43; p = 0.003630). CONCLUSIONS Acute or chronic dietary NO3- intake significantly increases maximal muscle power in humans. The magnitude of this effect-on average, ~ 5%-is likely to be of considerable practical and clinical importance.