The worldwide prevalence of diabetes is promptly increasing, and it has reached epidemic proportions. Type 2 diabetes (T2D) is more common in both developed and developing countries. Based on the statistics of the International Diabetes Federation (IDF), the current worldwide prevalence of diabetes is 8.3%. They have estimated that by the year 2035, the number of people with diabetes would reach up to 591.9 million. (1)
Diabetes is strongly associated with both microvascular and macrovascular complications causing organ and tissue damage in one-third to one-half of people with diabetes. Microvascular complications include retinopathy (disease of the retina which results in impairment or loss of vision), nephropathy (kidney disease), and neuropathy (disease or dysfunction of one or more peripheral nerves, typically causing numbness or weakness) and macrovascular complications include ischemic heart disease, peripheral vascular disease, and cerebrovascular disease. (2)
Good glycemic control is necessary for managing diabetes-related complications. Although various medications are used to reduce hyperglycemia in patients with diabetes, diabetes and its complications are still the main health challenges which most of these patients face.
Herbal medicines have been used for a long time for the treatment and control of blood sugar in patients with diabetes, and they have already been accepted as an alternative therapy. One of these plants is chamomile.
Chamomile, from the Asteraceae family, is widely consumed in Europe and West Asia. Consuming chamomile because of its healing properties can be dated back to ancient Greece and Rome. Every day, about one million cups of chamomile tea are consumed.
This plant is mainly used because of its anti-inflammatory, analgesic, antispasmodic, wound-healing, anti-microbial and sedation effects. As confirmed by different studies, chamomile has antioxidant, anti-parasitic, antiaging, and anti-cancer effects. The therapeutic property of chamomile is attributed to its components. The major bioactive compounds in chamomile include:
- Sesquiterpenic compounds such as α-bisabolol, bisabolol oxides A and B, chamazulene, and farnesene;
- Phenolic compounds, namely the flavonoids apigenin, quercetin, Patuletin, luteolin, and their glucosides, and also coumarins.
Several studies have indicated the hypoglycemic and hypolipidemic effects of chamomile. One study showed the hypoglycemic, hypolipidemic, and antioxidant effects of chamomile tea on patients with T2D (Rafraf et al., 2014). Another study reported that oral administration of aqueous extracts of chamomile at a dose of 20 mg/kg led to an improvement in glucose homeostasis in normal and streptozotocin-induced diabetic rats (Eddouks et al., 2005).
(Glucose homeostasis is the balance of insulin and glucagon to maintain blood glucose.)
In 2015, the researchers found that although several studies had indicated the effects of chamomile on glycemic control in animal models, only one study was done on human models (Rafraf et al., 2014). Moreover, they came to know that no study had been conducted on depressed patients with T2D.
Therefore, they designed a study titled "the effect of chamomile tea versus black tea on glycemic control and blood lipid profiles in depressed patients with type 2 diabetes” to investigate the effects of chamomile tea on glycemic control, including HbA1c and blood lipid profiles in depressed patients with T2D. (1) (HbA1c is your average blood glucose (sugar) levels for the last two to three months. (3))
Study Design and Participants:
74 depressed patients with T2D participated in this randomized controlled clinical trial. All patients were under the supervision of endocrinologists and psychiatrists and were selected via Beck-II questionnaires.
Inclusion criteria were:
- Duration of diabetes: 5-15 years;
- Beck test score: 11-30;
- No disorders and diseases of the kidney, liver, heart, and thyroid, bleeding disorders and malignancies, autoimmune diseases, and degenerative diseases of the central nervous system;
- No history of hospitalization for mental illness;
- Not using nutritional and antioxidant supplementation during the last 3 months;
- Not using sedative and diuretics during the last 3 months.
Exclusion criteria:
- Having allergy to chamomile;
- Major depression requiring special treatment (Beck test score more than 30);
- Individuals who during the interview, brought up the thoughts of suicide or history of events such as loss of job, divorce, or death of their relatives during last 3 months;
- People who preferred not to drink tea.
Then, the participants were assigned into two groups of 37: chamomile tea group and black tea group. The first group received 3 bags containing 2.5 g of chamomile tea and the second group received 3 bags containing 2.5 g of black tea. The researchers tested the amounts of tea polyphenols presented in both tea bags.
Tea preparation:
At the beginning of the intervention, the patients were advised to prepare their teas according to the instructions.
For 12 weeks, both groups placed each tea bag in 150 cc boiled water and drank it at least half an hour after every meal. The brewing time was the same for both groups.
The participants were asked to tick their consumption of chamomile or black tea in a form. They were also asked not to use another tea and not to change their physical activity, diet, pharmaceutical, and lifestyle as far as possible during the intervention.
Results:
After the intervention,
- The HbA1c mean showed a significant reduction in the first group (chamomile) in comparison with the second group.
- No significant changes were observed in serum lipids mean within and between groups.
- The Beck score significantly reduced in the first group.
- The mean changes showed a significant difference between the two groups.
Limitations of the Study:
- Some conflicting results were reported in this study. The reason might be the special conditions of patients who suffer from different degrees of depression.
- We investigated the effect of chamomile tea on depressed patients with diabetes. Therefore, the findings of this study cannot be generalized to the entire population.
- We did not measure other glucose levels' parameters in the subjects.
For better identification of the effects of chamomile, more human studies are needed.
Conclusions:
The study's results revealed that drinking chamomile tea for 12 weeks (three cups a day) by depressed patients with T2D improved glycemic control and depression state.
Therefore, drinking chamomile tea by these patients is recommended. However, more studies are needed to detect its effects on lipid indicators. (1)
1- http://jnfs.ssu.ac.ir/
2- https://www.ncbi.nlm.nih.gov/
3- https://www.diabetes.org.uk/
