Histidine is an essential amino acid with health benefits that include anti-inflammatory, anti-oxidant, glucoregulatory, and weight management. The current expert opinion for histidine intake is 8 and 12 mg/(kg body weight per day), an estimate that was extrapolated from the infant requirement for histidine. Further, the clinical safety of histidine supplementation above the average dietary intake has not been determined.The overarching objectives are to 1) measure the safety of histidine supplementation and 2) measure the potential benefits of histidine at doses above the average intake and current recommendation in a healthy adult population.
Histidine is an essential amino acid with health benefits that include anti-inflammatory, anti-oxidant, glucoregulatory, and weight management. Because of the extended period of time (\>35 days) that is required to deplete body histidine pools in adults, it has not been possible to fully determine histidine requirements. The current expert opinion for histidine intake is 8 and 12 mg/(kg body weight per day), an estimate that was extrapolated from the infant requirement for histidine. The average intake of histidine from a normal adult diet in the U.S., Europe, and Japan was reported between 2.12 and 2.40 g/day with the 99th percentile intake in men at 50-70 years of age consuming 5.20 g/day. The clinical safety of histidine supplementation above the average dietary intake has not been determined. Therefore, this study will utilize graded doses of histidine that are at are moderately above the average intake to identify safety and benefits of histidine in a healthy human population. Further, the clinical safety of histidine supplementation above the average dietary intake has not been determined.The overarching objectives are to 1) measure the safety of histidine supplementation and 2) measure the potential benefits of histidine at doses above the average intake and current recommendation in a healthy adult population. Following the completion and review of a health history questionnaire, vitals, and a biochemical panel, participants will be deemed healthy by a nurse practitioner and able to participate. After baseline measures are obtained, supplements (encapsulated histidine) will be provided at three graded doses (4 g/day, 8 g/day and 12 g/day) a forth dose (16 g/day) will be consumed if no adverse effects are observed at the three graded doses. Each dose will be for 28 days followed by a three week recovery period. At baseline, weeks 2 and 4 of supplement, and recovery a basic biochemical panel, anthropometric, urinary and serum zinc, will be conducted. Additionally, body composition will be conducted at baseline and week 4 of each dose. Changes in dietary intake and physical activity will be measured with 4-day food records and Actigraph activity monitors, respectively. Changes in sleep patterns will be measured with the Pittsburgh sleep questionnaire.
ingestion of encapsulated high quality histidine for four continuous weeks followed by a washout period of 3 weeks
Human Metabolic Research Unit
Ithaca, New York, United States
Change in concentration of zinc in mg/ml
The safety of histidine supplementation at each dose is monitored through blood markers of zinc
Time frame: at week 0 and 4 of each dose
Change in concentration of liver enzymes (ALT, ALP, and AST) in Units per Liter
The safety of histidine supplementation at each dose is monitored through circulating liver enzymes
Time frame: at weeks 0 (washout), 2 and 4 of each dose
Change in body weight in kilograms
The safety of histidine supplementation at each dose is monitored through changes in weight
Time frame: at weeks 0 (washout), 2 and 4 of each dose
Change in concentration of total protein and albumin in g/dl
The safety of histidine supplementation at each dose is monitored through circulating total protein and albumin
Time frame: at weeks 2 and 4 of each dose
Change in concentration of blood urea nitrogen, Creatinine, bilirubin and glucose each in mg/gL
The safety of histidine supplementation at each dose is monitored through circulating blood urea nitrogen, Creatinine, bilirubin and glucose
Time frame: at weeks 0 (washout), 2 and 4 of each dose
Change in concentration of C-reactive protein mg/L
The safety of histidine supplementation at each dose is monitored through circulating CRP
Time frame: at weeks 0 (washout), 2 and 4 of each dose
HgbA1c in %
The safety of histidine supplementation at each dose is monitored through circulating HgbA1c
Time frame: at week 4 of each dose
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Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
40
Change in heart rate in beats per minute
The safety of histidine supplementation at each dose is monitored through heart rate
Time frame: weeks 0 (baseline and washout), 1, 2, 3, and 4 of each dose
Change in systolic and diastolic blood pressures in mmHG
The safety of histidine supplementation at each dose is monitored through blood pressure
Time frame: weeks 0 (baseline and washout), 1, 2, 3, and 4 of each dose
Change in hours of sleep
The effects of histidine will be assessed with changes in sleep pattern as determined using a subjective measurement tool
Time frame: week 0 to 4 of each dose
Change in dietary intake of energy, macronutrients, and amino acids measured in kcals and g/day with 4 day food record
The effects of histidine will be assessed with changes dietary intake as determined with 4 day food records
Time frame: week 0 to 4 of each dose
Change in physical activity measured in steps per day
The effects of histidine will be assessed with changes in physical activity patterns using an Actigraph
Time frame: week 0 to 4 of each dose
Change in subjective mood measured in arbitrary units
The effects of histidine will be assessed with changes in mood as determined using a subjective visual analog scale. 100 mm line is anchored by two opposing statements. The higher number the greater the mood.
Time frame: week 0 to 4 of each dose
Change in subjective desire to eat measured in arbitrary units
The effects of histidine will be assessed with changes in desire to eat will be determined using a visual analog scale. 100 mm line is anchored by two opposing statements. The greater the number the stronger the desire.
Time frame: week 0 to 4 of each dose