Described as ‘herbal aspirin’, chamomile is one of the leading herbal remedies worldwide. There are a number of factors to consider when deciding on which foods or supplements to take for the purposes of health.
Scientific evidence is an important consideration, along with the cost. Even if the evidence is convincing and the cost is acceptable, there is still another major factor to throw into the mix. That factor is taste.
I really dislike the taste and smell of chamomile. It's just a personal thing. I am vaguely aware that there is some science to support some health benefits of chamomile.
Chamomile is very affordable and may even grow in your own back garden (as it does in mine). In order for me to include chamomile in my diet on a regular basis, it would have to have incontrovertible evidence of efficacy to justify that taste.
How strong is the evidence base behind 'nature's aspirin'?
What is Chamomile?
Chamomile or Matricaria recutita is a flowering plant that belongs to the Compositae (Asteraceae) or Daisy family. The word ‘chamomile’ comes from the Greek word for 'ground apple'.
Chamomile is also called Baboonig, Babuna, Banunj, and scented mayweed. It is also referred to as the 'star among medicinal species'.
Chamomile can grow within the temperature range of 2 to 20 degrees centigrade. Chamomile can accumulate sodium salts which can help to control salt concentration in topsoil. The roots are very shallow which means that the plant needs to be watered on a regular basis.
The peak flowering season for chamomile occurs during March-April every year. A fascinating tidbit of information from an Indian review paper suggests that 20 'units of labor' are required to collect flowers from an area as small as 0.25 hectares (1).
Chamomile is native to eastern Europe but is now found across Europe, the USA, and Australia. Over 5000 tons of chamomile are produced annually. Argentina is the main producer of chamomile and Germany is the main importer of this plant.
There are many varieties of chamomile but the two most common varieties are:
- Roman (M. nobilis) and
- German (M. recutita).
It is generally considered that the German variety (M.recutita) is the more potent species.
Over 120 key compounds have been identified in chamomile flowers which include 28 terpenoids, 36 flavonoids and 52 additional compounds with pharmacological activity.
Sesquiterpenes, flavonoids (apigenin, quercetin, patulin, and luteolin), coumarins, polyacetylenes including bisabolol and pectin like mucilage are the key bioactives in chamomile.
German chamomile oil is a source of blue essential oil, farnesol, chamazulene, and bisabolol (2).
It is used as medicine, food, and cosmetics.
It is also one of the most popular single-ingredient herbal teas (2).
The medicinal use of chamomile dates back to the times of ancient Greece and Rome. Good-old Hippocrates himself used to prescribe chamomile. I have great respect for Hippocrates (like all doctors I took his oath when I graduated from medical school).
I have some reservations about using the fact that Hippocrates used something as proof of concept (a very common practice). After all, poor Hippocrates had to make do with what he had available locally.
I do think that Hippocrates was an astute physician and great herbalist but this has to be balanced against the limitations of his time. Maybe if Hippocrates were alive today and an Amazon Prime shopper, he would use something else altogether.
The chamomile plant is used in a number of ways for medicinal purposes: the flowers are used as a tea, the plant extract is placed in pills and the oil is used in aromatherapy.
It is commonly used for digestion, skin, heart and mouth issues as well as for anxiety and depression. I also came across some more unusual uses for chamomile including wetting, migraine, and mastalgia (breast pain) which we will address in this article.
There are over 10,000 chamomile products for sale on Amazon. The average cost of 450 mg of chamomile ranges from 20 to 50 cents. Alternatively, you can have the chamomile in my garden for free.
Is There Any Research?
A systematic review of chamomile from 1990 to 2016 found 87 references and 69 were considered to be of decent quality (5). To put this into context, there are over 60,000 publications relating to pharmaceutical aspirin which includes almost 7000 clinical trials.
Does It Help Fight Cancer?
Iranian women with breast cancer who were undergoing chemotherapy were randomized to either ginger plus standard antiemetics (anti-vomiting pills) or chamomile plus standard antiemetics or standard antiemetics for five days before and five days after chemotherapy (6).
The study found no significant differences between the ginger, chamomile or control group suggesting that ginger or chamomile could be considered in this patient population. The ginger was noted to be significantly better at controlling symptoms of nausea and so was likely the overall winner from an herbal perspective.
A common and troublesome side-effect of chemotherapy is oral mucositis which refers to the loss of oral mucosa and ulceration. This can be extremely painful and can prevent patients from eating and drinking.
A study from 216 compared the effect of using chamomile during chemotherapy to a control group and found a statistically significant difference in the pain score and occurrence of mucositis in favor of the chamomile group (7). The chamomile was well-tolerated in this vulnerable patient population.
Recently, researchers from the UAE published the results of testing the anti-oxidant and anti-cancer effects of chamomile using a series of laboratory tests which they listed as DPPH, MTT and the Folin-Ciocalteu assay (8). Before we get lost in molecular biology, suffice it to say that chamomile looked promising as an anti-oxidant and possible anti-cancer agent.
There is no clinical evidence to suggest that chamomile has a direct anti-cancer effect, although it may make things easier for people undergoing chemotherapy.
Does Chamomile Fight Free Radical Damage, Pain & Inflammation?
Patients with osteoarthritis of the knee/knees were randomized to either chamomile oil, diclofenac gel or placebo three times daily for 21 days (9). Study participants were allowed to use oral acetaminophen as required. The study found statistically significant reductions in the use of acetaminophen as compared to the diclofenac or placebo arm.
No significant differences were noted in a validated questionnaire assessment of osteoarthritis symptoms. My small brain cannot reconcile these two findings - what people said and what people did were different. The chamomile crew said that they had no difference in symptoms but they took less analgesia? I don't like dissonance.
A randomized double-blind study comparing a blend of myrrh, chamomile plus coffee charcoal to standard treatment with mesazaline for colitis (l0). A total of 96 adults with known ulcerative colitis took part in this study.
No significant differences in relapse rates between the two groups were noted which lead the authors to suggest that future studies in the area are warranted.
There is no convincing evidence that chamomile has anti-inflammatory properties.
Does it Fight Insomnia, Anxiety, and Depression?
This is an area that is backed up by a number of clinical studies.
It is unknown how chamomile might exert an antidepressant effect but it is generally believed that it does. Possible mechanisms of action include effects on neurochemicals or the neuroendocrine system.
Generalized anxiety disorder is diagnosed when people have excessive worry about daily matters along with restlessness, fatigue, impaired concentration, irritability, muscle tension, and sleep disturbances.
Chamomile at a dose of 1500mg/day for 8 weeks was tested in an open-label study in 180 adults with a generalized anxiety disorder (11). The chamomile acted quickly in that responders had a 50% or greater improvement in their symptom scores within two weeks and 58.1% of study subjects had a meaningful response to treatment.
Encouraged by these results, the same researchers undertook a larger longer-term study. Adults with a diagnosis of generalized anxiety disorder were invited to participate in a 2 phase study at the University of Pennsylvania (the same department that carried out the depression study) (12).
Phase 1 of the study involved 12 weeks of chamomile 500 mg three times daily.
Phase 2 of the study involved randomizing responders to either placebo or chamomile. Logically, if chamomile worked, you would expect to see worsening symptoms or relapses in the placebo arm of the study.
Chamomile reduced symptom severity but did not significantly reduce the relapse rate. Another interesting and noteworthy observation was the fact that significant reductions in weight and BP were noted in the chamomile arm of the study.
Just last year, the same group studied the effect of chamomile in 45 adults with generalized anxiety disorder for 3 days and found statistically significant improvements in symptoms that were associated with beneficial changes in salivary cortisol (13). This advances the field even further and starts to explore the biological basis for the effects of chamomile on anxiety.
In another study, a total of 57 study subjects with symptoms of anxiety and depression were randomized to either chamomile or a lactose placebo (14). The study also took place at the Department of Family Medicine at the University of Pennsylvania but with different authors to the studies listed above.
The aim of the study was to build on the results of the earlier study which showed that chamomile has anxiolytic effects to specifically see if it has antidepressant effects. The interventions (chamomile or placebo) were started at a dose of one capsule per day and carefully titrated up to two capsules per day in the second week.
Study subjects who were noted to have a >/= 50% reduction in the depression symptoms score were further increased by one capsule per week to a maximum of 5 capsules per day.
A statistically significant reduction in depression score was noted in the chamomile treated study subjects as compared to the placebo arm of the study. The authors were satisfied that chamomile has antidepressant effects in addition to anxiolytic effects.
Now to look at sleep.
Elderly residents at a nursing home in Iran were randomly allocated to a chamomile extract or a wheat flour placebo for one month (15). Both groups reported poor sleep quality at baseline with no differences noted between the arms at baseline.
At the end of one month of intervention, the chamomile arm had statistically significantly improved sleep quality as compared to controls. The study team also reported that the chamomile was well tolerated.
In another related study, 80 Taiwanese post-partum women with poor sleep quality (I had no idea that there were post-partum women with normal or good quality sleep) were randomized to either chamomile or what they called ‘regular post-partum care’ (I wonder what that would be apart from changing diapers) (16).
There was a statistically significant improvement in sleep and mood initially but this returned to baseline after 4 weeks.
There is good evidence to support chamomile for anxiety, depression, and insomnia. I am doubly impressed with the fact that the same researchers systematically built on the results of their earlier studies which tells a very compelling story.
Does It Improve Heart Health?
There are 12 publications relating to chamomile and heart health. That being said, there are no human clinical studies looking at chamomile and heart health.
One non-human study is worth mentioning (17). Extracts of chamomile were tested for their ability to lower BP in rats. This was just a single dose study but it did show a decrease in systolic BP, diastolic BP and heart rate.
I don't need to include chamomile in my diet for my heart as there is no clinical evidence to justify it.
Does it Relieve Congestion?
There are no clinical studies to guide us here.
Part of the reason for the lack of data related to the fact that congestion is not really a medical/scientific term. Assuming that congestion means nasal stuffiness or sinusitis there are no studies on these topics.
Chamomile does not relieve congestion.
Does It Improve Digestion?
The key study on chamomile in infantile colic was published in 2017 and came from a group of Italian pediatricians (18). Colic is thought to be due to gut hypersensitivity. They randomized 166 infants with colic to either chamomile plus lemon balm plus Lactobacillus acidophilus (HA122) probiotics versus Lactobacillus reuteri DSM 17938 versus simethicone.
They measured mean daily crying and fussing time. If you have ever had a child with colic, I am sure you can actually hear the screams in your head. I certainly can. The study found that there was a statistically significantly higher response rate to the chamomile-lemonbalm-probiotic arm at 28 days.
Chamomile alone has not been shown to be of benefit for colic or diarrhea.
Does It Help Migraine?
Topical chamomile gel was tested in 100 patients who had migraine pain without an aura and this was compared to a placebo gel (19).
Symptoms of pain, nausea, vomiting, and photophobia were statistically significantly decreased in the chamomile arm of the study.
These results suggest that chamomile may be a useful strategy in people who suffer from migraines.
Care would have to be taken not to make things worse. Chamomile can cause dermatitis and I can't think of anything worse than having a full-blown migraine headache except maybe a full-blown migraine along with dermatitis.
Careful use of chamomile gel may help with migraine headaches (See side effects for more details)
Can It Help Bedwetting?
A very unusual study from Tehran School of Traditional Medicine (a very prolific source of papers on complementary and herbal medicines) looked at chamomile for urinary incontinence or bedwetting in children (20). They randomized 80 children to either chamomile oil or placebo for 8 weeks. The chamomile oil was blended especially for the study participants.
The placebo arm of the study used almond oil. The use of topical oils as a method of delivery of medicinal/therapeutic agents is common in Traditional Persian Medicine. The researchers bought chamomile flowers from a reputable local shop and had the plant formally identified by an experienced botanist.
The plant was dried, ground and boiled in an almond oil/water mixture. The chamomile oil was carefully applied to the area near the pubic bone and perineal area (the area around the vagina in girls and anus in boys and girls) at night.
The study enrolled boys and girls. The rationale for the study was the fact that chamomile can reduce the overactivity of the detrusor muscle at the neck of the bladder in addition to having action on the neuromuscular chemicals. The average frequency of wetting decreased significantly in the treatment arm of the study.
I think that this study is interesting but I would not recommend trying this at home. Topical oils are a specialty of Persian Medicine and significant damage could be done by placing the oils in the wrong place.
Does It Help Mastalgia?
Cyclic mastalgia (painful breasts) can precede menstruation in some women and can really impact negatively on their quality of life (21).
Chamomile drops taken three times daily were compared to placebo drops in 60 women. Statistically significant decreases in pain were noted in both groups and chamomile was statistically significantly better than placebo.
The authors of the study recommend that chamomile should now be studied head to head with standard treatments for mastalgia such as danazol or bromocriptine. This study was just published last year and it is too soon to expect follow-up studies.
Meantime, the authors recommend chamomile as a safe and effective alternative for this condition.
Mastalgia may be very uncomfortable but it is not life-threatening. For that reason, I think that even before we get the results of head-to-head studies, that it is entirely reasonable to try chamomile drops especially when we factor in the side-effect of danazol (voice changes and excessive hair growth) and bromocriptine (dizziness and constipation).
Does It Promote Skin Health?
A 6-month double-blind, placebo-controlled, randomized study on healthy post-menopausal females studied the effect of a combination of soy extract, fish protein polysaccharides, extracts from white tea, grape seed, and tomato, vitamins C and E as well as zinc and chamomile extract (22).
Improvements in wrinkles, sagging, laxity and pigmentation were noted in the treatment arm of the study but it is impossible to say which of the ingredients made the difference.
A study at UC Davis found that chamomile had anti-oxidant effects on skin cells in a laboratory model (23). Unfortunately, those skin cells were not actually attached to a human face which limits the impact of this study.
The effectiveness of chamomile for skin health is largely based on anecdotal reports from patients and physicians and not data.
Does It Help Diabetes?
Any herbal remedy looking for street credibility has to have something to offer diabetic patients. Short term intake of chamomile significantly improved glycemic control and antioxidant status compared to hot water in 64 adults with type 2 diabetes (24). The hot drinks (water or chamomile) were taken three times daily after meals in the study.
Very preliminary data suggests that chamomile may have anti-diabetic effects and is worth studying in larger trials.
Is It Safe?
Chamomile is generally regarded as safe (25).
Care should be taken when choosing a commercial brand of chamomile. Adulteration of chamomile with related species is common (1).
A quick hack to check the quality of chamomile blue oil is to check the depth of the blue color. The bluer the color, the higher the level of terpenoids and chamazulene in the oil (1).
Pollen in chamomile and especially when applied to the eye area can cause allergic conjunctivitis (26).
I have seen posts on-line claiming that chamomile has almost ‘no side effects’. I disagree. I have seen blogs that say that chamomile is safe in pregnancy and can be taken to relax the digestive tract in pregnant women and yet the very same blogs quote studies that say that chamomile can cause uterine contractions and should be avoided in pregnancy.
It is true that chamomile can cause uterine contractions (27). The basic rule in medicine is ‘First do no harm’. So says that Hippocratic Oath that I mentioned earlier. Therefore, the HBS stand on this is as follows: chamomile should not be taken during pregnancy.
There is a single case report of chamomile induced increase in breast milk production (galactogoue effect) (28). This could be a good or bad thing depending on your perspective in life.
People who are allergic to members of the daisy family can be cross allergic to chamomile. Additionally, chamomile can be contaminated with other plants eg dog fennel.
Chamomile interacts with blood-thinning medication and care should be taken in people who need these medications to avoid excessive bleeding.
Chamomile can increase the drug levels and toxicity of cyclosporin which is an anti-rejection drug used in renal transplant patients (29).
May I officially withdraw my earlier offer of giving away the chamomile in my back garden.
Despite my aversion to the taste of chamomile, I have to admit that I am impressed with some of the science around mood and sleep. I think that next time I feel a little stressed that I might just order a chamomile tea instead of a coffee.