Chamomile, a popular herbal tea, has frequently been associated with benefits for relaxation and sleep.
A new systematic review and meta-analysis published in Phytotherapy Research comprehensively analyzes the clinical research on chamomile for anxiety, insomnia, and sleep quality.
Key facts from this study:
- 12 randomized controlled trials with 965 total patients were included. Trials tested chamomile for generalized anxiety disorder, state anxiety, insomnia, and sleep quality.
- For generalized anxiety disorder, chamomile significantly improved symptoms after 2-4 weeks of treatment based on the Hamilton Anxiety Rating Scale. But effects were less significant after 8 weeks.
- Meta-analysis found chamomile did not significantly reduce state anxiety compared to placebo.
- Only 1 trial looked at insomnia and found no significant improvement with chamomile.
- However, meta-analysis of 6 trials did find chamomile significantly improved subjective sleep quality compared to placebo when measured on the Pittsburgh Sleep Quality Index scale.
- Chamomile had a fairly good safety profile, with only mild adverse effects reported in a minority of trials.
Source: Phytother Res.
Chamomile Tea: An Herbal Remedy with Rich History
Chamomile is one of the most ancient medicinal herbs, used since Egyptian times for healing purposes.
In the modern era, it is most commonly consumed as a tea to promote relaxation.
But many questions have remained about whether it truly exerts pharmacologic anti-anxiety or sleep-enhancing effects.
Researchers aimed to analyze the full body of clinical trial evidence to date with this comprehensive systematic review and meta-analysis.
Chamomile for Generalized Anxiety Disorder (GAD)
In total, they found 2 randomized controlled trials investigating chamomile for generalized anxiety disorder.
The largest and highest quality was a double-blind, placebo-controlled trial published in 2016, which used a pharmaceutical-grade German chamomile extract.
After 8 weeks of treatment, chamomile did not statistically separate from placebo on the Beck Anxiety Inventory.
However, it did show significant anti-anxiety effects on the Hamilton Anxiety Rating Scale at 2 weeks and 4 weeks of treatment.
This suggests oral chamomile can provide modest anxiolytic benefits for generalized anxiety disorder in the short-term over the first month of use.
The effects then become non-significant by 2 months of continued treatment.
More research is needed, but this level II evidence provides some preliminary support for the traditional use of chamomile tea to reduce worry and anxiety.
Chamomile for State Anxiety: Not Significantly Improved
For state anxiety, measured as situational anxiety at a single point in time, meta-analysis of 3 trials did not show a significant improvement with chamomile over placebo.
However, the researchers caution that the trials were small and had limitations like short treatment duration.
So current evidence is inconclusive for state anxiety reduction.
Insufficient Evidence: Chamomile for Insomnia
A single pilot trial was the only study identified that examined chamomile for insomnia disorder.
It did not find significant effects on the Insomnia Severity Index after 1 month of treatment.
Clearly, more research is needed before conclusions can be drawn about chamomile and insomnia.
But initial evidence does not demonstrate an effect.
Chamomile Improves Sleep Quality
The most robust evidence was for chamomile enhancing sleep quality in people without diagnosed insomnia disorder.
Meta-analysis of 6 randomized trials using the Pittsburgh Sleep Quality Index scale found chamomile significantly improved self-reported sleep quality compared to placebo after about 1 month of treatment.
Effects were shown using various oral dosing regimens across the trials.
So there is accumulating consistent evidence that chamomile can mildly improve sleep quality – even if it does not necessarily help diagnosed insomnia.
This adds supporting data for the traditional reputation of sipping chamomile tea before bed.
Chamomile Tea vs. Extracts: Does Formulation Matter?
An important question is whether drinking chamomile tea confers the same benefits as the more concentrated pharmaceutical extracts used in trials.
Most studies tested German chamomile extract in capsule form.
The researchers tested whether analyzing only the 3 trials using tea made a difference in the sleep meta-analysis.
The results did become non-significant, suggesting tea may be less potent.
However, more head-to-head comparisons are needed to draw definitive conclusions.
Mechanisms for Anti-Anxiety Effects of Chamomile
Chamomile contains a flavonoid compound called apigenin that may exert GABAergic effects in the brain and act as a mild sedative.
Apigenin has affinity for benzodiazepine receptors, helping explain the anti-anxiety properties.
But effects are likely much milder than prescription benzodiazepines.
Other active compounds like terpenoids may contribute additional relaxing properties.
So there are biologically plausible mechanisms by which chamomile flavonoids could impart mild anxiolytic and sleep-enhancing effects.
Chamomile is Usually Safe With Mild Side Effects
Across the 12 clinical trials analyzed, chamomile was found to be fairly safe with no serious adverse events reported.
The only side effects noted were mild gastrointestinal complaints and drowsiness.
This safety profile makes sense given chamomile has been used for centuries with little evidence of risk.
The authors conclude chamomile appears safe for short-term use, but more study is needed to confirm long-term safety.
Limitations and Need for Additional Research
Some important limitations temper the conclusions of this new analysis.
The trials were generally small with fewer than 100 patients each.
They varied in dosing protocols and potency of extracts.
And anxiety and sleep were measured by self-report questionnaires, which can introduce subjectivity compared to objective measures.
So larger, more rigorous trials are still needed to provide higher quality evidence around chamomile.
Takeaways: Chamomile for Anxiety & Sleep
What can we take away from this thorough review of the evidence on chamomile?
Results suggest it is worth trying for those with anxiety, especially generalized anxiety lasting months.
The data also indicates chamomile can mildly improve sleep quality for those struggling with things like falling asleep or restlessness.
However, those with clinically diagnosed insomnia may not see significant effects.
Drinking chamomile tea 1-2 times per day is worth a shot based on its safety profile and existing data.
People may want to additionally try standardized pharmaceutical grade extracts for maximal effects, but more comparative data is needed.
Chamomile is certainly not a panacea or equivalent to prescription medications.
But it may provide modest anxiolytic and sleep-promoting activity for some individuals.
For anxiety and sleep issues, chamomile should be considered as one part of an integrative approach including lifestyle, dietary, behavioral, and additional evidence-based natural supplements.
Those with more severe clinical anxiety or insomnia are encouraged to seek professional treatment.
But chamomile may still be a safe adjunct.
In summary, this high-quality systematic review provides justification for trialing chamomile as a natural intervention for mild to moderate anxiety and sleep problems.
Chamomile tea and supplements likely offer a safe complementary option.
But managing expectations is prudent.
Further rigorous research will help clarify the true therapeutic potential of this ancient herbal remedy.
References
