Apple cider vinegar and fenugreek seeds have been identified as the most potent herbal remedies for reducing fasting blood glucose and A1c levels in comparison to four other commonly used herbal treatments for type 2 diabetes, as indicated by a recent comprehensive review.
The review encompassed 44 randomized clinical trials, encompassing over 3000 participants, evaluating six herbal remedies: apple cider vinegar, cinnamon, curcumin, fenugreek seeds, ginger, and saffron.
Among these remedies, apple cider vinegar, fenugreek seeds, curcumin (turmeric), and cinnamon exhibited statistically significant reductions in fasting blood glucose in contrast to the control groups in the clinical trials. The review particularly highlighted apple cider vinegar as the most effective in reducing fasting blood glucose levels.
Furthermore, the study revealed that both apple cider vinegar and fenugreek seeds had a statistically significant impact on reducing A1c levels compared to the control groups. However, the herbal treatments did not appear to influence insulin levels or homeostatic model assessment for insulin resistance (HOMA-IR).
The findings, published in Diabetes & Metabolic Syndrome: Clinical Research & Reviews, aim to enhance the understanding of healthcare professionals and individuals with type 2 diabetes regarding the efficacy of diverse herbal remedies, potentially leading to their integration into standard care.
Shiv Mudgal, PhD, the corresponding author of the paper and an associate professor in nursing at the All India Institute of Medical Sciences in Deoghar, India, stated, “Some people use curcumin, some use ginger, some use apple cider, but it’s not clear which is better.”
The research aimed to elucidate the workings of these herbal solutions by assessing insulin levels and HOMA-IR as measurable outcomes, yet no definitive conclusions were drawn. Instead, the authors speculated that the effects of apple cider vinegar and fenugreek seeds on blood glucose and A1c could be linked to delayed gastric emptying and other mechanisms.
However, it’s essential to approach the results with caution, noted Subodh Kumar, MD, the first author and an associate professor in pharmacology at the All India Institute of Medical Sciences in Deoghar, India. The study found apple cider vinegar backed by three clinical trials and fenugreek seeds supported by four studies, both fewer than the other remedies. The authors also identified potential biases in randomization and allocation concealment in several of the included trials.
The majority of studies only encompassed short follow-up periods, leaving the long-term effects of these herbal remedies for managing type 2 diabetes largely uncertain.
Out of numerous popular complementary medicines, the six herbal remedies in the study were selected based on the strength and number of clinical trials supporting their use.
Merlin Willcox, DPhil, a clinical lecturer in general practice at the University of Southampton, UK, and not involved in the research, regarded the limited number of remedies in the review as a drawback. He noted that potentially effective solutions might have been omitted.
Willcox, who co-authored a review of herbal remedies for glycemic control in type 2 diabetes, expressed surprise that apple cider vinegar emerged as the most effective in this analysis. His review concluded that aloe vera leaf gel, psyllium fiber, and fenugreek seeds were most effective at reducing A1c in comparison to the control groups among 18 plant-based remedies.
Mudgal mentioned that no adverse effects were linked to the herbal remedies. However, the evidence for the effects of these remedies over the long term was also limited due to inadequate follow-up periods.
Willcox emphasized the importance of examining evidence for each individual remedy, considering factors like preparation and dosage. He cautioned against the risks associated with relying solely on herbal remedies to complement traditional therapies, as well as the potential pitfalls of obtaining information from unreliable sources.
Approximately 3.6 million individuals in the US utilize herbal remedies to manage type 2 diabetes, as reported in a 2014 study cited by the review authors. This number is substantially higher in other regions, with up to two-thirds of diabetes patients in India and Saudi Arabia incorporating herbal remedies. In the United Kingdom, about half of diabetes patients use herbal medicines.
Experts underscore the risks associated with utilizing herbal medicines alongside conventional treatments. Katherine H. Saunders, MD, DABOM, co-founder of Intellihealth and clinical assistant professor of medicine at Weill Cornell Medicine, highlighted the lack of high-quality data demonstrating efficacy and safety.
For Willcox, the risks are linked to the sources of information patients rely on. Many type 2 diabetes patients avoid discussing herbal medicines with their doctors due to apprehension of a negative or dismissive response. Patients often turn to family, friends, or the internet, sources that may not provide reliable, evidence-based information.
The authors have reported no relevant financial relationships.
Diabetes Metab Syndr. Published online July 7, 2023. Abstract