22 Jan Clinical proof lacking for the benefit of herbs and spices in GI disorders
January 21, 2019
Herbs and spices, like ginger, turmeric, peppermint, fennel, aloe vera, and garlic, have been used to treat ailments for centuries. What we don’t know is how most of them work and how they compare to modern medicine. To answer that second question specifically for functional gastrointestinal (GI) disorders, a research group led by Dr. Miguel Saps reviewed all published studies on the subject from 2000 to 2018. Functional GI disorders include abdominal migraine, functional dyspepsia, functional abdominal pain, and irritable bowel syndrome (IBS).
The herbs and spices with the most controlled clinical trials (with results published in English) are peppermint oil, STW5, turmeric, cannabis, aloe vera, and ginger.
Peppermint Oil: Scientists have learned that the menthacarin in peppermint oil is at least partially responsible for its soothing effect on the GI system. It works by blocking the calcium channels, which in turn relaxes the smooth muscle of the intestine. Peppermint oil can also relax the esophagus. Clinical trials with peppermint oil in patients with functional GI disorders consistently demonstrate a reduction in abdominal pain. In these trials, the recommended dosage was taken for at least two weeks. Most people were able to tolerate that dosage. Side effects were observed at high dosages and with individuals who also have gastroesophageal reflux disease (GERD).
STW 5: STW 5 is a combination of nine herbs that work together to alleviate symptoms associated with functional GI disorders. The science behind how the cocktail of herbs work is still being worked out. Clinical trials demonstrated that it is effective in treating IBS and dyspepsia symptoms over four weeks, and the best part…relief comes within an hour!
Turmeric: Turmeric is known to block inflammatory signals, thus acting as an anti-inflammatory agent. It has been used to treat inflammation in a variety of diseases including inflammatory bowel disease and diabetes. Scientists have guessed that it would also help in functional GI disorders either through reducing inflammation in the gut or acting on the gut-brain axis. Unfortunately the jury is still out on if and how turmeric helps in IBS. Multiple clinical trials have inconsistent findings.
Cannabis: There is a synthetic form known as Dronabinol. In clinical trials, there was no improvement in GI symptoms.
Aloe Vera: In addition to treating sunburns, aloe vera is believed to have anti-inflammatory, analgesic, and anti-diabetic properties. An oral form was tested to see if it would reduce GI symptoms. The results of three studies showed no significant improvement in symptoms and side effects were common amongst study participants.
Ginger: Ginger is known to sooth the gut. A small number of patients in the clinical trials noticed decreased abdominal pain and bloating. One study suggested this may be due to an increase in gastric emptying.
These clinical trials are all informative but have caveats. Most had a small number of participants and only compared the herb or spice to a placebo, not to the current standard treatment. As scientists and doctors learn more about how these ancient remedies work, we will be able to better use them to ease our GI systems and keep the side effects to a minimum.
If you’re interested in the scientific details, check out the following scholarly journal article.