Spices and diabetes: Urgent need for more human trials to assess benefits, say Asia researchers
Spices have long been known for their antioxidant, anti-inflammatory, and potential anti-diabetic properties, notes a review published in Food Chemistry.
The polyphenols in 80 spices have been proven to exhibit anti-glycation properties and could contribute to the prevention and management of diabetes, say researchers from Singapore’s Clinical Nutrition Research Centre, the Singapore Institute for Clinical Sciences, and the Agency for Science, Technology and Research (A*STAR)
“The spice polyphenols may influence glucose metabolism via several mechanisms, such as glucose absorption in the intestine, stimulation of insulin secretion from pancreatic b-cells, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in the insulin-sensitive tissues, and modulation of hepatic glucose output,” they write.
“Therefore, the seasoning of foods with spices has been suggested not only to increase the antioxidant content of meals, but also to have an anti-diabetic effect.”
Despite this, they add that the beneficial effects of spices in reducing fasting and postprandial glucose levels, as well as the interpretation of the actions of bioactive compounds in spices “remains complicated.”
The review assesses the research to support the notion that cinnamon, ginger, turmeric, cumin, coriander, aniseed, fenugreek, garlic and onion, cloves, mustard, black pepper and curry leaves can aid diabetes treatment.
“Currently, recommendations are warranted to support the consumption of spices which are rich in bioactive components for seasoning of foods at low-dosage,” it finds.
But with many South East Asia countries battling a diabetes epidemic - and the Singapore government declaring a 'war on diabetes - researchers add that there is considerable scope for further research.
“Most of the evidence presented has been based on cell culture or animal models instead of human model studies. Hence, there is an urgent need to carry out further studies in humans with spices that had been suggested to reduce glycemic response. It is imperative to confirm its effects and efficacy in human trials,” they write.
The review also points out that the mechanisms of individual phenolic compounds remain unknown because each spice usually contains a wide range of them.
Research is also needed on the metabolism of bioactive compounds in spices to propose recommendations on dietary intake, effective dosage, and dietary guidelines, notes the review. it also cautions that spices are generally used in seasoning of recipes in small amounts, and the chemical composition and bioavailability of antioxidant compounds may be affected during food preparation.
Nevertheless, the review concludes: “Seasoning of foods with spices may increase the daily intake of antioxidants and provide a possible means of decreasing the risk for developing diabetic complications and metabolic abnormalities.”
“[However], In future, a greater body of scientific evidence supporting the benefits of spices in the overall maintenance of health and protection from diseases will be expected.”
Source; Food Chemistry
Published online ahead of print: http://dx.doi.org/10.1016/j.foodchem.2016.08.111
“Spices in the management of diabetes mellitus”
Authors: Xinyan Bi, et al.