A new wave of international research is spotlighting the risks of high consumption of popular spices—particularly ginger, turmeric, and cinnamon—when used alongside prescription medications. While these aromatic staples have long been celebrated for their health benefits in both traditional Thai cuisine and medicine, current scientific evidence suggests that excessive intake, especially through supplements, could interfere with drug metabolism and trigger dangerous interactions, especially among individuals with chronic health conditions.
From Bangkok’s bustling markets to rural households across Thailand, ginger, turmeric, and cinnamon are cornerstones of everyday cooking and wellness rituals. The use of these spices is deeply entrenched in Thai culture, often recommended in local remedies and embraced for their perceived ability to boost immunity, reduce inflammation, or manage metabolic conditions. However, recent findings originating from a University of Mississippi study—now widely cited by health platforms including The Conversation and major international news outlets—are raising red flags about their safety in concentrated or supplemental forms, particularly for vulnerable groups or those already prescribed medications for chronic diseases.
According to the University of Mississippi research, compounds found in cinnamon—specifically cinnamaldehyde—were shown in laboratory tests to activate bodily receptors that accelerate the clearance of drugs from the bloodstream. This process could diminish the efficacy of key medications, such as blood thinners, diabetes drugs, antidepressants, and certain cancer treatments. Notably, cassia cinnamon, the type most commonly found in supermarkets throughout Thailand and Asia, contains high levels of coumarin, a powerful natural anticoagulant. When consumed in large quantities or combined with drugs like warfarin, coumarin can dangerously increase the risk of excessive bleeding or liver toxicity (CNN Health).
There are also significant differences between cinnamon varieties. “Cassia cinnamon, prevalent in Asian markets, carries higher levels of coumarin than the more expensive Ceylon cinnamon, increasing its potential for harm if overused,” confirmed a leading physician and adjunct associate professor at the George Washington University in an interview with CNN. While small amounts in food are not a concern, the danger lies in chronic or high-dose supplement use—still common in the Thai wellness community where herbal additives are seen as a natural health alternative.
Similar caution is urged with turmeric—widely used in Thai curries and traditional herbal treatments. The active ingredient curcumin has potent anti-inflammatory and antioxidant effects, but laboratory and animal studies indicate it can alter the function of liver enzymes crucial for metabolizing a wide array of prescription medicines. For example, excessive turmeric may intensify the effect of blood thinners (such as warfarin or aspirin), lower blood sugar levels to unsafe thresholds for those on diabetes medication, or amplify the blood pressure-lowering effects of antihypertensive drugs. These risks are not typically associated with the modest amounts consumed in home cooking, but rather with the considerably higher intake found in dietary supplements.
Ginger, a beloved ingredient for its anti-nausea and anti-inflammatory properties, also contains active compounds capable of affecting drug metabolism, particularly through mild blood-thinning action. High-dose or supplementary ginger, especially when combined with anticoagulant therapy, could heighten the risk of bleeding. There is mixed but growing evidence that ginger can interact with diabetes medications as well.
A recently published systematic review and meta-analysis in the Indian Journal of Rheumatology assessed eleven randomized controlled trials involving ginger, turmeric (curcumin), and cinnamon as adjunct therapies for rheumatoid arthritis. Researchers found that curcumin intake significantly improved inflammatory markers and disease symptoms, with minimal adverse events reported. However, evidence for ginger and cinnamon remains less robust due to limited well-controlled studies. Importantly, the review concluded: “Curcumin can be used to improve the outcome of rheumatoid arthritis conventional therapies, but more research is required to conclude the effective dose. Garlic, cinnamon and ginger are potential but remain understudied. Future studies should also consider other herbal plants based on the pre-clinical trial evidence” (SAGE Journals).
Historically, the integration of herbal remedies into the Thai medical system has brought both benefit and complexity. In 2019, the Thai Ministry of Public Health formally endorsed the use of certain traditional medicines for supporting chronic illness management, but strict warnings remain about unregulated supplement use and the interaction with conventional pharmaceuticals (Ministry of Public Health). Many Thais still consult local herbalists or turn to proprietary herbal products, often purchased from community markets without professional guidance.
Thai medical professionals consistently advise caution: “While culinary use is generally safe, patients—especially those managing heart disease, diabetes, hypertension, or cancer—should never start herbal supplements, including those containing ginger, turmeric, or cinnamon, without first consulting their doctor or pharmacist,” explained a clinical pharmacist from a major Bangkok hospital.
International drug safety authorities reiterate these warnings. The US Food and Drug Administration (FDA) does not regulate herbal supplements with the same rigor as pharmaceuticals, so safety and efficacy are not guaranteed. The FDA and European Food Safety Authority recommend restricting curcumin intake to no more than 3 mg/kg body weight, and caution that high or sustained intake—especially through supplements—may cause liver damage or intensify the effects of prescription drugs in unpredictable ways (National Center for Complementary and Integrative Health).
As Thailand sees a continuing rise in non-communicable diseases—such as diabetes and cardiovascular disease, both of which are often managed with chronic medication—the risk posed by unsupervised herbal supplement use also rises. Public health experts recommend a pragmatic approach for Thai consumers: trust in the safety of traditional spice amounts used in food, but avoid high-dose supplements unless prescribed within a medically supervised treatment plan.
Culinary use of these spices and herbs is not only a hallmark of Thai heritage, offering both flavor and a minor health boost, but also an opportunity to savor mindful, moderate practice. The risks highlighted by new research are not meant to discourage traditional cooking, but to raise awareness about the risks of self-medicating with unregulated supplements—a trend accelerated by social media and online marketing.
Looking forward, researchers and Thai health authorities are calling for more local studies to determine safe maximum doses for these commonly used herbs, as well as clearer education for both clinicians and the public. As the culture of wellness grows in Thailand and globally, the message is clear: moderate culinary use of ginger, turmeric, and cinnamon is safe for most people, but concentrated supplement use should always involve professional medical guidance.
Practical advice for Thai readers: Enjoy these treasured flavors in everyday cooking, but resist the temptation to self-treat serious illnesses with high-dose herbal supplements. Always inform your healthcare provider about any herbal products or supplements you may be taking, especially if you are on prescription medicine for chronic diseases. Stay updated with trusted resources and await further guidance from Thailand’s Ministry of Public Health regarding the integration of traditional and modern pharmaceutical care.
Sources: The Conversation, CNN Health, SAGE Journals, National Center for Complementary and Integrative Health, Ministry of Public Health