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Research seeds: Turmeric and dyspepsia

Turmeric and dyspepsia research seed
Turmeric (Curcuma longa)

In this article, we discuss the “Curcumin and proton pump inhibitors for functional dyspepsia: a randomised, double blind controlled trial”

Plant name and species

Turmeric (Curcuma longa)

Aim of study

To compare the efficacy of curcumin versus omeprazole in improving patient-reported outcomes in people with dyspepsia.

Study method

The study was  a randomised, double blind controlled trial. Participants were split into the following three groups; curcumin plus omeprazole (C+O), curcumin only (C only), and omeprazole only (O only). Each participant was provided with specific instructions to take two large capsules four times a day, along with one small capsule once a day, for a total duration of 28 days. These doses were based on the recommendation provided by the National List of Herbal Medicine committee. The Short-Form Leeds Dyspepsia Questionnaire (SF-LDQ) and the Severity of Dyspepsia Assessment (SODA) were used to assess symptoms.

Herbal preparation

Capsules containing 250mg of curcumin extracted from turmeric were used.

Sample size

Overall, the C+O group had 53 participants, the C group had 49 patients and the O group had 49 participants.

Results of study

At the beginning of the trial all 3 groups had similar levels of SODA scores (which measured pain intensity, non-pain symptoms and satisfaction). On day 56 there was a significant improvement in SODA pain intensity and non-pain symptoms and life satisfaction in the three groups, with no significant difference in efficacy between the groups.


Curcumin has been shown to be safe in numerous human studies, with only minor toxicity associated with the molecule. This is in part why it is increasingly being viewed as a biomolecule capable of being administered for an extended period without causing side effects. 

Side effects of headaches, nausea, vomiting and/or diarrhoea, stomach pain and constipation happen in more than 1 in 100 people taking omeprazole. More serious side effects after taking omeprazole for more than a year include bone fractures, gut infections and vitamin B12 deficiency as well as an increased risk of developing stomach cancer (1). 

Curcumin was shown to be effective in all of the subtypes of functional dyspepsia, and while both curcumin and omeprazole were both effective for functional dyspepsia they did not seem to have a synergistic effect. Interestingly patients with a high body mass index indicated a trend towards liver function impairment in the curcumin group, and so larger studies are needed. However, this could indicate a common issue with the reductionist method of extracting isolated compounds from plants instead of administering whole plant extracts in their more natural and traditional preparations. Normally herbalists administer whole turmeric preparations to support liver function. Isolating a compound from the plant means we lose the synergy effect which can both decrease safety and efficacy.

Curcumin is an isolated compound found in turmeric and is administered here in high concentrations. Although curcumin is naturally found in turmeric, it is not normally present in such high levels. However, the chemical complexity of more traditional natural extracts means that there is a whole array of other medicinal compounds found that can contribute synergistically to both the therapeutic efficacy of the plant and its safety. 


Curcumin and omeprazole worked equally well for treating functional dyspepsia, and curcumin seems to be a safer option long term. Administering the two medicines together made no difference to efficacy.


Website N. Side effects of omeprazole. nhs.uk. Published July 5, 2023. https://www.nhs.uk/medicines/omeprazole/side-effects-of-omeprazole/

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