Studying the impact of some commonly used spices on glycemic index and -load of a carbohydrate-rich meal

This study aimed to evaluate the impact of some commonly used spices on glycemic index (GI) and glycemic load (GL). Cumin (Cuminum cyminum), ginger (Zingiber officinale), and coriander fruits (Coriandrum sativum L.) were the used spices in this study, whereas the widely consumed carbohydrate-rich boiled potato was chosen as the test food. The study included 10 healthy, non-diabetic participants, 6 males and 4 females aged between 20 and 30 years with Body mass index (BMI) below 25 (BMI: mean±SD, 20.98±3.43). On specific meeting days over 5 weeks, the participants consumed the following test meals: glucose (standard food), boiled potato (test food), boiled potato with 0.5g of cumin, boiled potato with 0.5g of coriander, and boiled potato with 0.5g of ginger. Each meal was consumed with 150ml of water after 10-12 h overnight fasting. The glycemic index values were calculated after measuring capillary blood glucose at 0, 30, 60, 90 and 120min. The values of blood glucose responses and the blood glucose incremental area under curve (IAUC) of boiled potato decreased significantly after adding the studied spices (P<0.05). The GI and GL values for boiled potato with each type of the studied spices (GI=88.73, GL=12.32 for boiled potato with cumin, GI=86.53, GL=12.02 for boiled potato with coriander and GI=85.01, GL=11.81 for boiled potato with ginger) were significantly lower than boiled potato alone (GI=93.33, GL=12.96) (P<0.05). The GI and GL values of boiled potato with ginger were significantly the lowest (P<0.05). Despite this significant decrease in GI and GL values of boiled potato after adding the studied spices, their values remained high and intermediate, respectively (GI ≥70 and GL=11-19) and therefore unsuitable for diabetics. This study indicated that spices such as ginger, coriander and cumin had significant impact on GI and GL.