vaccinium corymbosum l ( vc ) ( blueberries ) and laurocerasus officinalis ( lo ) are summer fruits native to the black sea region . vc contains polyphenols and flavonols which contribute to the powerful antioxidant effect and may diminish glucose level . vaccinium vitis - idaea which is another species of this plant has a positive effect on decreasing glucose and lipid levels . its antioxidant and radical scavenging activities were found to be comparable to or higher than those of the reference antioxidants . we present a case of profound hypoglycemia after combined use of vc juice and lo fruit . a 75-year - old male patient was brought to the emergency department with a complaint of loss of consciousness , after 1 - 2 minutes of cold sweats , palpitations , dizziness and blurred vision . physical examination carried out revealed unconsciousness , loss of cooperation and orientation , cold and sweaty body , arterial blood pressure of 110/70 mmhg , heart rate of 124 pulse / minute and respiratory rate of 24/minute . the patient 's body temperature was normal and there was no evidence of infection . during the follow - up infusion of 20% dextrose was continued . at the end of first hour , the patient was reevaluated . the patient 's pg at the 1 hour was 146 mg / dl and he was clinically stable . when the infusion was stopped , pg decreased rapidly , thus the infusion was continued for nearly 12 hours . the patient had been diagnosed with pre - diabetes before 2.5 years ; his body mass index was 31.5 kg / m . the patient had performed self - finger stick blood glucose test one month ago and glucose level was 92 mg / dl . he used to drink a cup of vc juice ; he boiled the fruit , filtered it and drank it daily for 2 years . about 1.5 to 2 hours before the development of hypoglycemia , the patient had consumed up to 500 ml vc juice and 250 - 300 gram of lo fruit . even though he had not taken hba1c was 4.9% , insulin was 3.5 u / ml ( 5 - 10 u / ml ) and homa - ir was 0.57 . the serum fasting pg was 67 mg / dl , on 2 day it was 91 mg / dl and on 3 day it was 96 mg / dl . physical examination and the laboratory findings of the patient remained completely normal and the patient was discharged . he had continued to drink a cup of vc juice daily during these 3 months . fasting pg was 91 mg / dl , hba1c was 4.9% , insulin was 2.8 u / ml , homa - ir was 0.63 , and the rest of laboratory parameters were normal . some 6 months after development of hypoglycemia , his laboratory tests were increased ( fasting pg was 105 mg / dl and hba1c was 5.5 ) . hypoglycemia is the most common cause of syncope and it is a complication of treatment with oral anti - diabetics or insulin . hypoglycemia may also occur in long - term fasting , liver , kidney and adrenal gland failure and in geriatric patients due to poor diet . this patient had no evidence of organ failure , neurological and cardiac diseases or poor diet . we ruled out insulinoma , as these was no history of weight loss and the insulin / glucose ratio was 0.11 and insulin level was 5.3 u / ml . additionally , 3 months later , his physical examination and laboratory tests were normal . although there was not risk factor for hypoglycemia , the development of hypoglycemia with the use of high doses of these plants suggests that it occurred due to the use of two plants together . moreover , it is also known that majority of pre - diabetic patients who do not comply with medical treatment , dietary and lifestyle changes develop overt diabetes . however , the patient 's pg and hba1c levels were within normal range . the levels of pg and hba1c after 3 months of stopping vc juice were increased . naranjo probability scale is generally the most accepted and widely used method for causality assessment in clinical practice . this score for our patient was eight and it was , therefore , inferred to be probably an adverse drug reaction of vc juice . this may be an unexpected effect of an interaction occurring between the chemical compositions of the two plants . both plants can reduce pg levels by reducing oxidative stress and insulin resistance and may be as alternative treatments for diabetes .
an emergency intervention was performed in a 75-year - old male patient with hypoglycemic attack and blackout . 
 although he was diagnosed with prediabetes before 2 years , he did not take any anti - diabetic drug or follow dietary advice . 
 he drank vaccinium corymbosum l ( vc ) juice daily with a belief that it increases sexual potency . before the development of hypoglycemia 
 , the patient had consumed about 500 ml vc juice in addition to eating 200 - 300 gram of laurocerasus officinalis ( lo ) fruit . 
 the measured plasma glucose ( pg ) level during loss of consciousness was 30 mg / dl . 
 the profound hypoglycemia may be an unexpected side effect of an interaction between the chemical compositions of the two plants , occurred as a result of lo fruit intake that may have a strong pg - lowering effect or related to excessive intake of vc juice . 
 both plants may be considered in the alternative treatment of diabetes .