Background: Tapioca is one of the staple foods of the people of Kerala. If it is not prepared properly during cooking the cyanide present in it will interfere with body functions. The cyanide is metabolized into thiocyanate by the liver. Thiocyanate has been shown to interact with the blood pressure and thyroid function.

Objectives: The objectives of the study are to observe the variation in physiology of the human body due to the effect of low dose cyanide in diet on the blood pressure and thyroid function.

Materials and methods: A descriptive cross-sectional study design was conducted in the department of General Medicine out-patient department of a tertiary care hospital of central Kerala. This research was conducted after obtaining ethical clearance from the institutional ethical committee. The blood pressure of each subject was recorded. The fasting TSH values of each subject were determined.

Results: There were no significant changes in the systolic blood pressure in hypothyroid group (p=0.288) and hyperthyroid group (p=0.915). There were no significant changes in diastolic blood pressure in hypothyroid group (p=0.270) and in hyperthyroid group (p=0.813). There was significant difference in TSH values in the hypothyroid group (p=0.001) and in the hyperthyroid group (p=0.001) compared to the matched controls.

Conclusions: The above study did not show significant changes in the systolic and diastolic blood pressure compared to matched controls.  These findings are unusual since thyroid dysfunction is known to cause increase in blood pressure as seen in various other studies. This means low dose cyanide in diet in a population with cassava as staple food might be protective from hypertension and is good for the cardiovascular system. There was significant increase in TSH values in the hypothyroid group. There was significant decrease in TSH values in hyperthyroid group. These findings are comparable with the values obtained in other studies.

Systolic blood pressure, Diastolic blood pressure, TSH

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