The advice to fill up on curry if you have indigestion may sound counterintuitive. Indeed, if you call the local takeaway for a vindaloo every time you experience heartburn, the chances are you will make your gastric misery worse.
However, reaching for a rogan josh might make more sense in light of new research that suggests a key curry ingredient, the spice turmeric, may be an effective treatment for indigestion.
Researchers at Thailand’s Chulalongkorn University found that compounds in turmeric, specifically curcumin, may be as effective in treating indigestion as drugs for excess stomach acid, such as omeprazole.
In the study, 200 patients aged between 18 and 70 with recurrent stomach problems were given either curcumin capsules or omeprazole, or both, for 56 days, during which they were questioned about their levels of pain and other symptoms. By day 28, all groups said their symptoms had reduced and by day 56, the improvements were even stronger, with the group taking curcumin reporting almost the same relief as those on omeprazole.
An associate professor at the university, Dr Krit Pongpirul, explains: “Turmeric has been used by Thai traditional medicine (TTM) doctors for relieving dyspepsia-like [indigestion] symptoms. It has been included in Thailand’s National List of Herbal Medicines, but good scientific evidence is still essential. TTM doctors generally recommend a powder form of turmeric capsule because fresh turmeric contains a much lower amount of curcuminoids.”
The benefits of turmeric supplements
Turmeric has been used in traditional Southeast Asian medicine for hundreds of years and is believed to have benefits for people suffering from a range of conditions, including high blood pressure, arthritis, depression, anxiety and even heart disease, cancer, and Alzheimer’s.
The compound mainly thought to be behind its health-giving properties, curcumin, gives turmeric its yellow pigment. It is thought that its benefits derive from its anti-inflammatory and antimicrobial properties.
Curcumin was first isolated in 1815 by two German scientists. The first study on its biological activity as an antibacterial was published in 1949 in Nature and the first clinical trial was reported in The Lancet in 1937. Although there are now around 9000 publications on curcumin listed on the US biomedical database detailing tests of its effectiveness against various cancers, diabetes, obesity, cardiovascular, pulmonary, neurological and autoimmune diseases, it is still accepted that more research needs to be done.
Curcumin is in a class of plant compounds called polyphenols. These natural compounds have been observed to regulate numerous biological processes and enzymes linked to inflammation, which plays a major role in many common chronic illnesses, including neurodegenerative, cardiovascular, respiratory, metabolic and autoimmune diseases.
It is this natural anti-inflammatory action that makes turmeric effective against arthritis. According to a review of research published in Food Journal, there is scientific evidence that eight to 12 weeks of turmeric extract treatment (typically 1000mg/day of curcumin) can reduce arthritis symptoms. The US Arthritis Foundation recommends 500mg of curcumin twice a day to reduce inflammation, but as scientific research is limited for long-term use, it’s best to use it for flare-ups.
Curcumin has also been observed to lower cholesterol levels in patients with cardiovascular risk factors, according to another review of controlled trials published in the Nutrition Journal in Oct 2017. Subjects who received turmeric and curcumin experienced a natural cardioprotective effect, with a lowering of “bad” cholesterol and triglycerides, compared to subjects who did not. Levels of “good” cholesterol remained unchanged.
How to take turmeric
For those keen on reaping the health benefits of the spice, which comes from the stem of the Curcuma longa plant, there are caveats. Fresh turmeric – which tastes like a mild, warming ginger and is now sold in some supermarkets – is generally considered safe as it contains only between 0.3 and 5.4 per cent curcumin. Powdered turmeric is also recommended for its health benefits.
For a more turbo-charged turmeric hit, curcumin is available in tablet form in various concentrations in health food stores and online. However, the compound is not easily absorbed by the body. Fortunately, research shows that combining fresh turmeric and curcumin supplements with black pepper may help increase absorption, primarily because a substance in pepper called piperine increases the rate of curcumin absorption by 2000 per cent. For this reason, many curcumin supplements are formulated with black pepper.
The best curcumin supplements
When buying supplements, one of the most important things to be aware of is the distinction between turmeric and curcumin products. Generally, turmeric powders and supplements offer a whole-foods approach, retaining more of the root’s nutrients, while curcumin supplements provide an isolated form of the most active antioxidant compound found in turmeric.
To confuse matters further, there is a distinction between products that contain basic turmeric and those that contain turmeric extract, which is around 20 times stronger than the standard food-grade turmeric used in some supplements, meaning it also has a far higher percentage of curcuminoids.
Turmeric added to food, either as powdered spice or as fresh root, contains considerably lower doses of curcumin than tablets, and the strength of supplements varies considerably. Holland and Barrett, for example, sells products ranging from gummies with 500mg of turmeric to bio-fermented turmeric liquid with 1000mg of turmeric, 250mg of black pepper and 20mg of curcumin.
Experts recommend reading the ingredients label of any supplement carefully and avoiding bulking agents such as magnesium stearate, titanium dioxide, starch, iron oxide or microcrystalline cellulose, which don’t offer any nutritional benefit. It is generally accepted that supplements with higher curcumin levels and added pepper will be more effective as they contain more active ingredients – however, when taking supplements for medical reasons, it is always advisable to speak to a doctor or registered dietician for advice first.
How much should I take?
As a regular supplement to aid general well-being, some experts recommend buying tablets with around 200mg of turmeric extract, and 20mg of black pepper extract or BioPerine, but if you’re taking it to help with a chronic condition or you’re on other medication, check with your doctor first.
There is no reference nutrient intake (RNI) for turmeric per see, but there is for curcumin. The World Health Organisation advises a daily dose of up to 3mg per kg of bodyweight of curcuminoids, which includes curcumin. The average daily intake in an Indian diet, however, is much higher with no apparent ill-effects - between 60 and 100mg per kg of bodyweight.
Dosage and choice of turmeric or curcumin will depend on whether it is being used to treat a specific condition. For example, as mentioned above, eight to 12 weeks of 1000mg/day of curcumin has been shown to reduce arthritis symptoms.
According to the NHS Specialist Pharmacy Service, when taken as a medicine, a common dose of turmeric is 400 to 600mg three times a day, which is equivalent to 60g of fresh turmeric root or 15g of turmeric powder. In clinical cancer trials, doses of 4000 to 8000mg (4 to 8g) a day of curcumin are typical.
Turmeric side effects
Jo Cunningham is a registered dietician at Green Light Nutrition and is a specialist in digestive disorders, gut health and cancer. She explains that while fresh and powdered turmeric added to food is generally beneficial and safe, taking high doses can be problematic.
“I wouldn’t blanket recommend taking high-dose turmeric or curcumin supplements because although there are some studies that say high doses might be safe, it has also been found to impede the effects of several chemotherapy drugs,” she explains. “For anyone being treated for cancer, I would normally recommend adding turmeric to food in fresh form or as a powdered spice, not as a supplement.
“However, we do know turmeric has anti-cancer effects, and studies show it can prevent cancer growth and kill some types of cancer cells, although most of these studies are in animals. It can reduce inflammation, and inflammation is at the root of lots of diseases, including some cancers and arthritis.”
She advises that anyone being treated for cancer should speak to an oncology pharmacist before taking curcumin supplements.
There are also a range of other cautions related to high-dose turmeric supplements. They may increase the risk of kidney stones and they can lessen the efficacy of aspirin, ibuprofen and paracetamol. For people taking warfarin or other blood thinners, turmeric supplements may also increase the risk of bleeding.
People taking tacrolimus medication, which is used to treat a range of skin complaints, are also advised against consuming high amounts of curcumin. People with allergies to some spices may develop a rash, hives or abdominal pain.
Cunningham says the results from the Thai study should also be treated with caution.
“There are occasions when someone who has dyspepsia [indigestion] and takes a lot of turmeric can worsen the condition. I advise a simple food approach. Add it as an ingredient little and often. Dried or fresh are both beneficial. Go with what you like the best.”
More research is needed
Despite being among the most studied dietary supplements, experts say more studies into turmeric are needed before it can safely be recommended as a treatment for chronic conditions. Earlier this year researchers at the University of Arizona, led by professor of medicine Dr Janet Funk, evaluated 389 clinical trials on how curcumin supplements may influence various health conditions, including type 2 diabetes, osteoarthritis, digestive conditions, cancer and dementia.
They concluded that the evidence suggests supplements may help people with osteoarthritis, insulin resistance and diabetes, but cautioned that many of the studies were small and were not well designed. A similar criticism has been levelled against the Thai indigestion study because there was no placebo included.
So, if you are looking to tune in to the benefits of turmeric safely and if you want a change from curry, try making a turmeric latte, buying fresh turmeric to add to cooking or sprinkling some spice on your scrambled egg or over rice with black pepper.
The five health benefits of turmeric
- Joint pain relief. Several studies show that curcumin is an effective anti-inflammatory and provides the same level of relief for arthritic pain as common drugs such as ibuprofen and aspirin.
- Alzheimer’s disease. A study conducted at UCLA found that curcumin may help boost the activity of macrophage cells within the body, helping them to clear the damaging proteins, called amyloid plaques, found in Alzheimer’s disease. Macrophages play an important role in the immune system – they help the body fight against foreign proteins and then effectively clear them.
- Depression and mental illness. A 2019 meta-analysis of research projects concluded that curcumin, if added to standard care, might improve depressive and anxiety symptoms in people with depression. A 2020 study published in Frontiers in Psychiatry suggested that curcumin had a positive effect on a number of pathological processes that caused depressive disorders.
- Brain health. Turmeric’s antioxidant and anti-inflammatory properties may also help in preventing or reducing the symptoms of other neurodegenerative diseases such as dementia, Huntington’s disease, multiple sclerosis and Parkinson’s disease.
- Heart disease. Studies have found that curcumin improves the function of the lining of blood vessels, the endothelium. Endothelial dysfunction causes blood pressure and blood clotting problems and is a major cause of heart disease. One study also found that for heart health, curcumin can be as effective as exercise in postmenopausal women.